AGM M4 GBB

[snorkelman]

tbh it seems like they're getting bought by the bucket load at the moment, so you'll see RA-Tech going out of stock every few days or so (they were out of stock for a few days last week, came back into stock and then sold out again) Personally I'd just keep an eye on it or email them and ask when its next back in.

 

The adjustable npas aluminium bolt on its own at 60 dollars will fit - attach that to your stock AGM nozzle tube stick the lot back into your AGM bolt carrier along with the AGM oring (ditch the RA-tech red one)

 

The complete npas adjustable set with steel bolt carrier at 260 bucks will fit too, Im running that on here just get the WA part number one (their prime/ino one is longer)

 

The only combo I've had any difficulty with was the middle ground option - ie the complete npas aluminium bolt and nozzle assembly (150 bucks) when fitted into an AGM bolt carrier - my AGM carrier has the hole for the sidelock plate 0.5mm lower down side of the AGM bolt carrier than the RA-Tech steel bolt carrier has its hole. As a result if i try to fit the entire RA-tech internals into the AGM bolt carrier the RA-T side plate refuses to fit.

 

The complete 150 buck assembly (same one used in the complete bolt carrier 260 buck option) is quite nice The RA-tech nozzle tube features removable nozzles you can buy for a couple of bucks each, which is handy feature if you chew one up and might prove cheaper in long run than buying complete new nozzle plastic tubes at 15 to 20 bucks a pop if they're in the habit of chewing regularly.

 

the full 260 buck assembly still has a niggle or two Id have liked to see fixed in particular the loose fit of their aluminium side lock plate in their steel bolt carrier

 

i.e. unless theres something I've missed that makes a loose fit for these two parts somehow desirable, then I dont see why they cant make the two parts a nice snug fit (or better still modify the two parts to allow a small loctited grub screw to be used to hold them together for extra peace of mind)

 

[Stealthbomber]

Just to input something I've found when asked to "fix" an AGM M4 (I've searched and it hasn't been addressed):

I was able to fix the forward assist by simply stretching out the spring underneath the ratchet arm. It was squashed up and making the arm sit too low, barely making contact with the notches on the bolt carrier.

Mine is currently in bits again while I repaint the receiver and I took a look at the f/a at the same time.

I agree about the spring but I also think the casting of the part that locks into the ratchet is a bit soft and rounded.

As well as replacing the spring I'm going to try and sharpen the front edge slightly with a dremel sanding drum.

[the hot tuna]

tbh it seems like they're getting bought by the bucket load at the moment, so you'll see RA-Tech going out of stock every few days or so (they were out of stock for a few days last week, came back into stock and then sold out again) Personally I'd just keep an eye on it or email them and ask when its next back in.

 

The adjustable npas aluminium bolt on its own at 60 dollars will fit - attach that to your stock AGM nozzle tube stick the lot back into your AGM bolt carrier along with the AGM oring (ditch the RA-tech red one)

 

The complete npas adjustable set with steel bolt carrier at 260 bucks will fit too, Im running that on here just get the WA part number one (their prime/ino one is longer)

 

The only combo I've had any difficulty with was the middle ground option - ie the complete npas aluminium bolt and nozzle assembly (150 bucks) when fitted into an AGM bolt carrier - my AGM carrier has the hole for the sidelock plate 0.5mm lower down side of the AGM bolt carrier than the RA-Tech steel bolt carrier has its hole. As a result if i try to fit the entire RA-tech internals into the AGM bolt carrier the RA-T side plate refuses to fit.

 

The complete 150 buck assembly (same one used in the complete bolt carrier 260 buck option) is quite nice The RA-tech nozzle tube features removable nozzles you can buy for a couple of bucks each, which is handy feature if you chew one up and might prove cheaper in long run than buying complete new nozzle plastic tubes at 15 to 20 bucks a pop if they're in the habit of chewing regularly.

 

the full 260 buck assembly still has a niggle or two Id have liked to see fixed in particular the loose fit of their aluminium side lock plate in their steel bolt carrier

 

i.e. unless theres something I've missed that makes a loose fit for these two parts somehow desirable, then I dont see why they cant make the two parts a nice snug fit (or better still modify the two parts to allow a small loctited grub screw to be used to hold them together for extra peace of mind)

 

What are the differences between the $150 assembly and the $260 full assembly? That $110 difference is looking good.

[Stealthbomber]

What are the differences between the $150 assembly and the $260 full assembly? That $110 difference is looking good.

$150 buys you the bolt - the part that's plastic on the AGM gun.

$260 buys you the bolt and the bolt carrier. That's the whole thing that whizzes backwards and forwards.

 

On green gas your bolt carrier takes quite a hammering (especially if the bolt catch works) and a replacement bolt carrier will cost you $100 at least. A steel one from RA-tech will cost $130.

 

Perhaps it's prudent to buy the whole lot at the same time and receive it all pre-assembled and ready to go?

[the hot tuna]

Okay, I just needed that cleared up. I will get the full assembly as you suggested, thanks.

 

I didn't know the stock "thing that whizzes back and forth" was plastic.

[snorkelman]

Perhaps it's prudent to buy the whole lot at the same time and receive it all pre-assembled and ready to go?

 

The only real benefit of buying them together as one assembly is that 20 bucks saving

 

Sure it turns up preassembled but then folks can find they have to take it apart, throw away the ill-fitting red o-ring in favour of an off the shelf one and stick it back together again, much same as you would if you bought the two parts seperately

 

Its also worth checking the e-clip they fitted closely as mine was warped and sloppy fit straight out of the box A few hundred rounds and it was so dished and opened out that it just wouldnt hold the spring retainer onto rear of the blowback chamber. Chucked a fresh one of my own in its place and its been fine since

 

[Luis21]

See, I really hate RA-Tech right now.

 

They're making a monopoly off of us right now. Even some real commercial AR-15 bolts and carriers aren't even that expensive and they're mil spec!!! But hey, they can sell it however they want since they're the only ones who make an NPAS......

 

Sure, the complete NPAS might be a good deal since a single Prime CNC'ed steel bolt carrier is just $174 plus HK shipping.

 

But dang, for $260 I can buy a WE SCAR. Hopefully you don't ever, ever, ever have to buy any bolt carrier group part again besides a $5 nozzle for that price.

 

However, I'm very skeptical on buying the complete set right now.

 

I am noticing that the weak part when using green gas/propane is the back of the whole loading nozzle/bolt. Part #2.

 

The whole loading nozzle tank seems to be handling the propane/green gas fine. All I was thinking of getting was the $60 metal NPAS part. Again just part #2. Keep the plastic AGM loading nozzle and I think you'll be good to go. This route would be so much cheaper and I think it'll last. Just get a bolt carrier of your choice.

 

Also snorkelman, you said that with the $260 BCG that you had to replce WA part #1? That's the whole loading nozzle. Can you verify that?

 

Also can you give us an over view of the $260 BCG? How's the blowback? Which nozzle do you prefer? Plastic?

 

I'm thinking the upper receiver might break in the long run with the metal bolt face returining to battery with so much energy behind it.

 

Please let me know before I shell out so much.

 

And again, for $260 you better not have to replace anything on the BCG.

 

Thanks,

 

-Luis

[crasstoe]

Could I just buy this and fit it to the standard bolt & bolt carrier?

 

Which metal hop up is the easiest to use?

[Luis21]

Could I just buy this and fit it to the standard bolt & bolt carrier?

 

Which metal hop up is the easiest to use?

 

You could do that but Snorkelman mentioned that the sidelock plate(part #7) won't secure the bolt/loading nozzle because the hole on the AGM bolt carrier doesn't align.

 

I'd wait until Snorkelman verifies that. However I'd recommend securing the little steel insert on the AGM bolt carrier or getting a new bolt carrier. If the little steel insert on the bolt carrier that engages the bolt catch falls off then your bolt will get torn up like this:

 

 

 

Beware.

 

As for the metal hop-up, Prime is a good choice. I'd look into the PGC hop-up for AEG barrels.

 

-Luis

 

[snorkelman]

@ luis - the only replacement of parts I did to the complete RA-Tech kit was the eclip (part 18) and the o-ring (part 19) Anythign else Ive mentioned changing,replacing or swapping was strictly temporary - e.g. to see how a 150 dollar kit or a 60 dollar kit bought on their own would fit along with AGM parts.

 

@crasstoe - as luis said when I was fitting the parts you get in the 150 bucks kit into a stock AGM bolt carrier I didnt have the clearance neccessary to fit the RA-T aluminium side plate. The cut out in the side of the AGM bolt carrier was the right size to fit the sidelock (without a bolt inside the bolt carrier the sidelock could slip straight in), it was just positioned half a mill further down than on the RA-T bolt carrier - which meant the groove inside the sidelock wasnt capable of lining up with the ridge on the side of the RA-T aluminium nozzle tube thats meant to run along it.

 

YMMV though, might just have been mine.

 

@ luis again, as far as the 260 buck set goes you get everything you'll need:

 

A the RA Tech aluminium nozzle tube which is equiv of WA part 1 (the only real difference other than material its made from is that you can unscrew the nozzle from the main tube and replace the nozzle as a seperate part)

 

B the RA Tech aluminium adjustable NPAS bolt (the equiv of Wa part 2 and does away with WA parts 3 4 5 11 and 12) this comes assembled with the remaining bolt parts - WA part numbers 10 13 14 17 18 19 and 166 - though I'd give their eclip (part 18) a thorough check for distortion and I'd dump their red o-ring (part 19) in favour of a normal off the shelf one

 

C an aluminium version of WA part 7 - the side lock plate

 

D a steel version of the bolt carrier.

 

 

buy the 260 dollar kit and you get A, B, C and D

 

buy the 150 dollar kit you get A and B (I think maybe C with it?)

 

buy the 60 dollar kit you get B

 

 

that 60 dollar kit B is going to be an improvement over the usual plastic part 2, but it is subject to the same impact forces on its rear face, so I wouldnt expect it to last forever, eventually its going to fail at same point as the plastic ones. Whats going to matter is how long it takes before it does that. I'd like to think it'll take a fair while.

 

Thats not the only place the standard bolt setup breaks though, I've seen a few folks posting broken plastic nozzle tubes (WA part 1), if you're going to buy the 60 dollar set B then you're obviously still going to be as succeptible as ever to those part 1 breakages.

 

Going by where it breaks (and a quick look at the stock AGM plastic parts) I cant help wonder wether part of the problem might be with the fit of part 1 to part 2:

 

When you fit the two parts together part 1 has a keyed section that part 2 locates in, and then a thru pin goes thru both parts at that point to hold them together. So far so good

 

But looking at the fit of the two AGM parts when assembled here, thats the only real point of contact between them. The entire rear face of part 1 has a tiny gap between it and the corresponding face of part 2.

 

Soooo, if the front face of part two is getting smacked by the inside of the bolt carrier, then Id expect most of the impact force transferring thru to part 1 is focused in that little area around the thru pin, not spread around the entire rear face of part 1. Might explain why part 1 has a tendency to give out around the thru pin

 

the only other thing to consider if you're looking at the 60 bucks kit is that theres no upgrade path available from RA-Tech if you stat with that part

 

e.g. if you buy the 150 buck kit you can go back later and buy the steel bolt carrier for 130 - you take a 20 dollar hit compared to buying the two parts together but thats it.

 

however if you buy the 60 bucks part, then although you could go back later and buy a steel RA-T bolt carrier, there isnt the option of buying an RA-T aluminium nozzle tube (WA part1) on its own to complete the set.

 

 

As far as the stock AGM bolt carrier goes Im not really sure theres anything you can do to secure the little steel reinforcing nub set into the front of it where it contacts the bolt catch. It looks for all the world like a tiny steel pin thats been cast into the bolt carrier itself. Give it enough whacks and its going to loosen up inside the carrier and then drop out. I think the original WA carrier uses same design and suffers same problem? Id reckon best the end user could do is keep an eye on it, clean up the bolt carrier once it eventually falls out, then just keep cleaning the carrier up as it gets chewed (untill eventually its so far back along the carrier that the bolt catch no longer catches it).

 

Far as hop units go Id be inclined to just buy the red RA-T hop rubber and shove it into the stock AGM hop unit and see how it goes. I went the whole hog bought the RA-teh cnc'd chamber as well as their hop rubber.

 

Works fine, no dribblers rolling out the barrel (and no over hop now the AGM arm has been fettled to fit it properly), but seeing as it is the AGM arm thats in there and the AGM adjuster cylinder attached to it I do have to ask myself just how much of that is actually down to the 55 dollar CNC'd hop unit and how much is down to the 7 dollar red hop rubber inside it

Edited July 19, 2009 by snorkelman

[Luis21]

@ luis - the only replacement of parts I did to the complete RA-Tech kit was the eclip (part 18) and the o-ring (part 19) Anythign else Ive mentioned changing,replacing or swapping was strictly temporary - e.g. to see how a 150 dollar kit or a 60 dollar kit bought on their own would fit along with AGM parts.

 

@crasstoe - as luis said when I was fitting the parts you get in the 150 bucks kit into a stock AGM bolt carrier I didnt have the clearance neccessary to fit the RA-T aluminium side plate. The cut out in the side of the AGM bolt carrier was the right size to fit the sidelock (without a bolt inside the bolt carrier the sidelock could slip straight in), it was just positioned half a mill further down than on the RA-T bolt carrier - which meant the groove inside the sidelock wasnt capable of lining up with the ridge on the side of the RA-T aluminium nozzle tube thats meant to run along it.

 

YMMV though, might just have been mine.

 

Anyways as far as the 260 buck set goes you get everything you'll need:

 

A the RA Tech aluminium nozzle tube which is equiv of WA part 1 (the only real difference other than material its made from is that you can unscrew the nozzle from the main tube and replace the nozzle as a seperate part)

 

B the RA Tech aluminium adjustable NPAS bolt (the equiv of Wa part 2 and does away with WA parts 3 4 5 11 and 12) this comes assembled with the remaining bolt parts - WA part numbers 10 13 14 17 18 19 and 166 - though I'd give their eclip (part 18) a thorough check for distortion and I'd dump their red o-ring (part 19) in favour of a normal off the shelf one

 

C an aluminium version of WA part 7 - the side lock plate

 

D a steel version of the bolt carrier.

 

 

buy the 260 dollar kit and you get A, B, C and D

 

buy the 150 dollar kit you get A and B (I think maybe C with it?)

 

buy the 60 dollar kit you get B

 

 

that 60 dollar kit B is going to be an improvement over the usual plastic part 2, but it is subject to the same impact forces on its rear face, so I wouldnt expect it to last forever, eventually its going to fail at same point as the plastic ones. Whats going to matter is how long it takes before it does that. I'd like to think it'll take a fair while.

 

Thats not the only place the standard bolt setup breaks though, I've seen a few folks posting broken plastic nozzle tubes (WA part 1), if you're going to buy the 60 dollar set B then you're obviously still going to be as succeptible as ever to those part 1 breakages.

 

Going by where it breaks (and a quick look at the stock AGM plastic parts) I cant help wonder wether part of the problem might be with the fit of part 1 to part 2:

 

When you fit the two parts together part 1 has a keyed section that part 2 locates in, and then a thru pin goes thru both parts at that point to hold them together. So far so good

 

But looking at the fit of the two AGM parts when assembled here, thats the only real point of contact between them. The entire rear face of part 1 has a tiny gap between it and the corresponding face of part 2.

 

Soooo, if the front face of part two is getting smacked by the inside of the bolt carrier, then Id expect most of the impact force transferring thru to part 1 is focused in that little area around the thru pin, not spread around the entire rear face of part 1. Might explain why part 1 has a tendency to give out around the thru pin

 

 

as far as the stock AGM bolt carrier goes Im not really sure theres anything you can do to secure the little steel reinforcing nub set into the front of it where it contacts the bolt catch. It looks for all the world like a tiny steel pin thats been cast into the bolt carrier itself. Give it enough whacks and its going to loosen up inside the carrier and then drop out. I think the original WA carrier uses same design and suffers same problem? Id reckon best the end user could do is keep an eye on it, clean up the bolt carrier once it eventually falls out, then just keep cleaning the carrier up as it gets chewed (untill eventually its so far back along the carrier that the bolt catch no longer catches it).

 

Thanks for the great info Snorkel. I really appreciate it.

 

However how do you like your $260 set-up? How hard is it striking the front of the receiver where the nozzle goes in?

 

Thanks,

 

-Luis

[sacairsoftsn00py]

I was just shooting my AGM M4 GBBR outside today. It has not been that hot out here in Virginia USA. Its probably only gotten around the mid 70's to mid 80's...Perfect skirmish weather IMO. I have the following parts installed in my gun:

 

Pro-Arms Hi-Power Loading Nozzle

Pro-Arms Hop Up Unit

KM 6.04mm TN barrel for M4

Guarder Hard Type Hop Bucking

G&P Steel Bolt catch

RA-Tech Winter Recoil Spring

 

I have been shooting on semi-auto for a good 90+ percent of my guns life in my hands. Today, the stock AGM flute valve broke in half on me. It has been 10 days since I have had the gun. I have shot under 2000 rounds through it using green gas/propane through the gun. I have only used 134a/duster gas for about 2-3 magazine's worth of BBs.

 

In the 10 days that I have owned the gun (and under 2000 rounds through it), I have done the following:

 

1. Busted the reinforced steel inserts on the bolt carrier and bolt catch

2. Cracked the Loading Nozzle

3. Busted the flute valve

4. Two of the magazines leak from the top through the output valve.

5. Cracked Part #7

 

I have 4 other magazines that hold gas. I have not put BBs through the other magazines I have. On both of the leaky magazines, the o-ring in the output valve keeps on getting "sucked in"/ dislodged.

 

Based on the parts diagram that came with the AGM M4, the o-rings have a 3mm inner diameter with 1mm cross section and 5mm total diameter. I have measured it using a ruler ( i dont have any fancy shmancy calipers to use) and the o-rings hold true to the measurement from the manual.

 

I hopped on e-bay and found 3mm ID x 1mm o-rings. I also found some 4mm ID x 1mm orings. Each packet cost $2.50 plus $2 shipping for one 50 piece packet of o-rings. I plan on using these o-rings to replace the stock valve o-rings that the gun came with.

 

I also found some 3.5mm ID x 1.5mm and 3mm ID x 1.5mm o-rings on Amazon. I purchased some of them as well (just in case the o-rings above does not work). Do note that the o-rings from Amazon cost more. It was $0.99 for a pack of 5 for the measurements I just posted. Shipping cost was a little over $7.

 

---------------

 

 

From experience, the gun is not advisable for those who are not mechanically inclined. It costs quite a pretty penny repairing the gun and there is no guarantee that your gun will work and hold up even with the upgrade parts installed.

 

What started out as $178 now has the following spent on it:

 

$62 for Pro Arms Hop Unit and Hi-Power Loading Nozzle

$39 for G&P Bolt Catch

$22 for RA-Tech Winter Recoil Spring

 

I have also purchased the following parts for the following reasons:

 

$115 for Airsoft Surgeon Light Weight Bolt Carrier - lighter bolt carrier means easier cycling/crisper blowback (more resistant to wear than the pot metal Bolt Carrier Group)

 

$19 for G&P Anti Rotation Llinks- to keep the lower receiver pins from popping out (I could manually push the trigger pin out)

 

$45 Airsoft Surgeon Loading Nozzle- Intended to be a just in case part but now, I have a busted flute valve and cracked part #7.

 

$8 MAG replacement spring set for WA M4- just in case part

 

$10 G&P Hop Bucking for WA M4 -intended to replace the stock hop bucking...just in case the Pro-Arms hop unit breaks on me.

 

I will post up which setup works best to save some people cash. At least you know which parts would end up breaking...

 

[snorkelman]

Thanks for the great info Snorkel. I really appreciate it.

 

However how do you like your $260 set-up? How hard is it striking the front of the receiver where the nozzle goes in?

 

Thanks,

 

-Luis

 

Has only had couple of thousand rounds/powered cycles thru it thus far so not much of a test, but the only places showing any wear at all are:

 

1 inside of the charging handle (where the front of the fake gas key on top of the bolt carrier contacts against it) its worn a very faint circle in the paint of that part

 

2 the lip of the hop up chamber has enough wear to remove the black anodized finish (but only the actual facing edge that sits right against the barrel extension, not the chamfered area leading to hop rubber)

 

3 one segment of the moulded in barrel extension has a teeny chip of paint missing from it, all the other segments are all unscratched

 

everythign else - face of the bolt carrier, face of the gas key, face of the aluminium bolt (and the removable white plastic RA-Tech nozzle screwed into that) are all wear free. Not a mark or score or nibbled bit out of any of them yet.

 

to be honest the AGM cast bolt carrier is pretty heavy to start with, so not as though ones a super-lightweight part and the other a hulking steel monster - on the scales theres only 30-odd grammes or so difference between the complete RA-Tech unit (241g) and the cast metal AGM carrier with plastic AGM bolt (206g)

 

 

[Luis21]

I was just shooting my AGM M4 GBBR outside today. It has not been that hot out here in Virginia USA. Its probably only gotten around the mid 70's to mid 80's...Perfect skirmish weather IMO. I have the following parts installed in my gun:

 

Pro-Arms Hi-Power Loading Nozzle

Pro-Arms Hop Up Unit

KM 6.04mm TN barrel for M4

Guarder Hard Type Hop Bucking

G&P Steel Bolt catch

RA-Tech Winter Recoil Spring

 

I have been shooting on semi-auto for a good 90+ percent of my guns life in my hands. Today, the stock AGM flute valve broke in half on me. It has been 10 days since I have had the gun. I have shot under 2000 rounds through it using green gas/propane through the gun. I have only used 134a/duster gas for about 2-3 magazine's worth of BBs.

 

In the 10 days that I have owned the gun (and under 2000 rounds through it), I have done the following:

 

1. Busted the reinforced steel inserts on the bolt carrier and bolt catch

2. Cracked the Loading Nozzle

3. Busted the flute valve

4. Two of the magazines leak from the top through the output valve.

5. Cracked Part #7

 

I have 4 other magazines that hold gas. I have not put BBs through the other magazines I have. On both of the leaky magazines, the o-ring in the output valve keeps on getting "sucked in"/ dislodged.

 

Based on the parts diagram that came with the AGM M4, the o-rings have a 3mm inner diameter with 1mm cross section and 5mm total diameter. I have measured it using a ruler ( i dont have any fancy shmancy calipers to use) and the o-rings hold true to the measurement from the manual.

 

I hopped on e-bay and found 3mm ID x 1mm o-rings. I also found some 4mm ID x 1mm orings. Each packet cost $2.50 plus $2 shipping for one 50 piece packet of o-rings. I plan on using these o-rings to replace the stock valve o-rings that the gun came with.

 

I also found some 3.5mm ID x 1.5mm and 3mm ID x 1.5mm o-rings on Amazon. I purchased some of them as well (just in case the o-rings above does not work). Do note that the o-rings from Amazon cost more. It was $0.99 for a pack of 5 for the measurements I just posted. Shipping cost was a little over $7.

 

---------------

 

 

From experience, the gun is not advisable for those who are not mechanically inclined. It costs quite a pretty penny repairing the gun and there is no guarantee that your gun will work and hold up even with the upgrade parts installed.

 

What started out as $178 now has the following spent on it:

 

$62 for Pro Arms Hop Unit and Hi-Power Loading Nozzle

$39 for G&P Bolt Catch

$22 for RA-Tech Winter Recoil Spring

 

I have also purchased the following parts for the following reasons:

 

$115 for Airsoft Surgeon Light Weight Bolt Carrier - lighter bolt carrier means easier cycling/crisper blowback (more resistant to wear than the pot metal Bolt Carrier Group)

 

$19 for G&P Anti Rotation Llinks- to keep the lower receiver pins from popping out (I could manually push the trigger pin out)

 

$45 Airsoft Surgeon Loading Nozzle- Intended to be a just in case part but now, I have a busted flute valve and cracked part #7.

 

$8 MAG replacement spring set for WA M4- just in case part

 

$10 G&P Hop Bucking for WA M4 -intended to replace the stock hop bucking...just in case the Pro-Arms hop unit breaks on me.

 

I will post up which setup works best to save some people cash. At least you know which parts would end up breaking...

 

Thanks for the great report Snoopy.

 

I would also definitely not recommend this gun to those who are NOT willing to put in work, money, and time into it. If you have high expectations for this gun, don't get it.

 

However this is a great platform for a beast rifle. You're essentially paying for the externals and the trigger components.

 

You can go balls out on upgrades and you'll still be under a brand new WA or G&P.

 

I personally am going to make my AGM undestructible internally and still be under $500. I feel that it's great since you spend about the same for a bomb-proof AEG set-up.

 

Now that I look at it, the RA-Tech complete bolt carrier group is the way to go.

 

Also I'm assuming the winter spring is lighter since gas guns have more problems cycling during the cold and need less resistance from the buffer spring, correct? And that the summer spring(or whatever it's called) is stiffer because the hotter it is the faster that bolt carrier is going to kick so a little more resistance is good, correct?

 

I am also trying to get the hardest possible kick out of my AGM. The stock blowback is super weak. Hopefully the heavier steel bolt and a lighter buffer spring will make this possible.

 

-Luis

 

EDIT: Thanks Snorkel. Sounds like it's a good buy so far, only time will tell in the long run. It comes with the plastic nozzle correct? Or did you buy it separately?

 

Edited July 19, 2009 by Luis21

[sacairsoftsn00py]

For harder kick, I would go with a heavier bolt carrier, heavier recoil spring guide rod, lighter tension recoil spring, stock recoil buffer, more durable charging handle...

 

my reasoning:

 

Heavier bolt carrier group, the more mass/dense the punch will be...lighter recoil spring, the quicker the blow back....

 

The rate of fire will be slower and there will be lesser shock when the bolt slams into the hop unit. The bolt face comes in contact with the back of the hop unit.

---------

 

I am going for responsiveness with a lighter bolt. Faster ROF=more rounds put through the gun before the magazine cools down should i decide to go full auto. The lesser the kick, the more accurate your follow up shot will be.

 

I do hope I can find the right combination for this sucker. I hope I'm lucky enough that the parts I ended up buying lines up with the seals from the magazine, bolt carrier group seals, and nozzle-hop seal. I'd like full auto function to be as good as can be even if I don't really use it. I should find out in a week or so.

 

----------

 

I was considering the RA-Tech bolt carrier group but there's so many mixed reviews on them when installed in an AGM M4...

Edited July 20, 2009 by sacairsoftsn00py

[snorkelman]

EDIT: Thanks Snorkel. Sounds like it's a good buy so far, only time will tell in the long run. It comes with the plastic nozzle correct? Or did you buy it separately?

 

Aye they supply it with a white plastic nozzle already screwed into their aluminium nozzle tube (Wa part1), the spare aluminium nozzles they sell seperately for 3 bucks a pop and the spare white plastic ones are 2 bucks each.

 

as far as springs go the RA-Tech winter spring and AGM standard spring are pretty much identical, I've included an RA-T summer spring (RAT-S) for comparison

 

 

gauge

AGM 0.47"

RAT-W 0.47"

RAT-S 0.55" (17AWG)

 

O/D

AGM 23.0mm

RAT-W 23.2mm

RAT-S 23.5mm

 

coils

AGM 34

RAT-W 34

RAT-S 33

 

uncompressed length

AGM 300mm

RAT-W 310mm

RAT-S 290mm

 

basically if you do the maths on them the AGM and RAT-W work out to be within 5 percent or so of each other, while the RAT-S is around 1 and a half times as strong

 

Edited July 20, 2009 by snorkelman

[Luis21]

For harder kick, I would go with a heavier bolt carrier, heavier recoil spring guide rod, lighter tension recoil spring, stock recoil buffer, more durable charging handle...

 

my reasoning:

 

Heavier bolt carrier group, the more mass/dense the punch will be...lighter recoil spring, the quicker the blow back....

 

The rate of fire will be slower and there will be lesser shock when the bolt slams into the hop unit. The bolt face comes in contact with the back of the hop unit.

---------

 

I am going for responsiveness with a lighter bolt. Faster ROF=more rounds put through the gun before the magazine cools down should i decide to go full auto. The lesser the kick, the more accurate your follow up shot will be.

 

I do hope I can find the right combination for this sucker. I hope I'm lucky enough that the parts I ended up buying lines up with the seals from the magazine, bolt carrier group seals, and nozzle-hop seal. I'd like full auto function to be as good as can be even if I don't really use it. I should find out in a week or so.

 

----------

 

I was considering the RA-Tech bolt carrier group but there's so many mixed reviews on them when installed in an AGM M4...

 

That's good reasoning you got there for your light weight bolt option.

 

However you said that if I went with the heavier bolt that there would be less shock when it slams back into the hop-up unit. Not true. The RA-tech Bolt Carrier Group(BCG) is heavy, so it'll be carrying more energy on it's way forward so it'll hit with more force.

 

 

Aye they supply it with a white plastic nozzle already screwed into their aluminium nozzle tube (Wa part1), the spare aluminium nozzles they sell seperately for 3 bucks a pop and the spare white plastic ones are 2 bucks each.

 

as far as springs go the RA-Tech winter spring and AGM standard spring are pretty much identical, I've included an RA-T summer spring (RAT-S) for comparison

 

 

gauge

AGM 0.47"

RAT-W 0.47"

RAT-S 0.55" (17AWG)

 

O/D

AGM 23.0mm

RAT-W 23.2mm

RAT-S 23.5mm

 

coils

AGM 34

RAT-W 34

RAT-S 33

 

uncompressed length

AGM 300mm

RAT-W 310mm

RAT-S 290mm

 

basically if you do the maths on them the AGM and RAT-W work out to be within 5 percent or so of each other, while the RAT-S is around 1 and a half times as strong

 

Thanks for the info Snorkel. You're today's MVP, the most valuable poster.

 

I'm assuming that even thought the summer spring is shorter that it's still stiffer due to the larger gague.

 

Thanks,

 

-Luis

Edited July 20, 2009 by Luis21

[sacairsoftsn00py]

I made a mistake with that statement. Hopefully its not a sign of me having alzheimers disease

 

You get the idea

 

On a side note, I might have another part coming in the next 4 days. I purchsed an Airsoft Surgeon Bolt Carrier assembly. The carrier comes with a pre-installed bolt/ loading nozzle. Hopefully its a straight drop in kit that will get that blasted AGM M4 shooting right on both semi auto and full auto.

 

Airsoft Surgeon Loading Nozzle for WA M4

$64.30

----------------------------------------------------------------

Airsoft Surgeon Light Weight Aluminum Bolt Carrier for WA M4

G&P Anti-Rotation Links for WA M4

G&P Hop Up Bucking for WA M4

MAG Spring Kit for WA M4

$188.30

----------------------------------------------------------------

RS Charging Handle for AR-15

RS AR-15Castle Nut Wrench

$39.85

----------------------------------------------------------------

4mm ID x 1mm Orings (50 count)

$4.50

----------------------------------------------------------------

3mm ID x 1mm Orings (50 count)

$4.50

----------------------------------------------------------------

3mm ID x 1mm orings (10 count)

3mm ID x 1.5mm orings (10 count)

$11.46

----------------------------------------------------------------

Airsoft Surgeon Bolt and Loading Nozzle Set for Western Arms (WA) M4A1 Series

$101.02

 

I also purchased some o-rings hoping I could remedy the leaky output valve issue that I along with everyone else who uses propane/green gas seems to have with the AGM magazines...

 

 

hot dang....a little over 400 bucks. 100 bucks probably ended up being eaten by shipping....

[Luis21]

Should of went with the $260 RA-Tech BCG or even an Inokatsu BCG for $185 off AEX.

 

However I think that you'll find your set-up and that you'll save alot of people money so we appreciate that.

 

The airsoft surgeon BCG's are the ones that come stock in the G&P WOCs. They should be pretty good. Just be sure to buy alot of part #2's since they will break after long propane/green gas use.

 

-Luis

[Stealthbomber]

I didn't know the stock "thing that whizzes back and forth" was plastic.

Erm, hang on...

 

I said the bolt was the plastic part. That's the thing you get (in aluminium IIRC) for $160

 

For $250 you get the bolt AND blot carrier. The stock bolt carrier isn't plastic. It's pot metal with a tiny steel insert where the bolt catch is supposed to lock it.

The RATech bolt carrier is, I think, Steel.

 

I'm thinking the upper receiver might break in the long run with the metal bolt face returining to battery with so much energy behind it.

That's an interesting point.

 

I wonder if the built-in "barrel extension" in the AGM gun actually causes the bolt assembly to come to a stop more forcefully than in the original design. Could this be what's causing the cracks people see in the back of their bolts rather than them being caused by green gas?

[snorkelman]

That's an interesting point.

 

I wonder if the built-in "barrel extension" in the AGM gun actually causes the bolt assembly to come to a stop more forcefully than in the original design. Could this be what's causing the cracks people see in the back of their bolts rather than them being caused by green gas?

 

bolt face doesnt get to ground out against the extension

 

e.g. drop a bolt carrier group into the upper without a charging handle in there and the bolt will seat around 0.7mm deeper into the extension than it will with the charging handle in place. The fake gas key on top of the carrier bottoms out against the inside face of the charging handle first

 

likwise remove the bolt from the bolt carrier and drop the bolt down into the upper on its own, when pressed fully home into the extension it'll go another mil or so deeper again

 

so between the bolt carrier itself and the gas key on top of it, the bolt face is around 1.5mm or so away from being fully home/grounding against the barrel extension

 

 

 

 

 

[Stealthbomber]

bolt face doesnt get to ground out against the extension

 

e.g. drop a bolt carrier group into the upper without a charging handle in there and the bolt will seat around 0.7mm deeper into the extension than it will with the charging handle in place. The fake gas key on top of the carrier bottoms out against the inside face of the charging handle first

 

likwise remove the bolt from the bolt carrier and drop the bolt down into the upper on its own, when pressed fully home into the extension it'll go another mil or so deeper again

 

so between the bolt carrier itself and the gas key on top of it, the bolt face is around 1.5mm or so away from being fully home/grounding against the barrel extension

Erm, okay...

 

I was actually talking about whether the bolt carrier hits against the outer edge of the barrel extension.

I must admit, I dunno if the tab on the end of the charging handle is what takes the impact instead though.

[snorkelman]

Erm, okay...

 

I was actually talking about whether the bolt carrier hits against the outer edge of the barrel extension.

I must admit, I dunno if the tab on the end of the charging handle is what takes the impact instead though.

 

nopes bolt carrier stands off from the face of the extension by the 0.7mm when charging handle is in place (otherwise bolt carrier and bolt would be reaching same depth with charging handle in or removed)

 

does look like the impact is on the charging handle - little circle of wear to the metal on the inside face of the handle where the fake gas key sits against it, and corresponding bruising of the finish on outside of it where outside face of the handle rests against the little rubber bump stop thats fitted in the upper.

 

in comparison theres zero wear on finish of front face of the carrier (other than where it strikes the mag catch) but wear can be seen on the finish on front face of its gas key.

 

 

 

 

 

 

[sacairsoftsn00py]

There is wear on the inner part of the charging handle where the bolt carrier latches on to so you can pull the bolt carrier group back. I'm thinking that a mod could be done so a buffer material can be added in place in addition to the one thats inside the top receiver. Perhaps shave down the contact point on the charging handle and glue a rubber padding on it.

 

Some people have opted to go with a RS charging handle. I got one for myself just in case the stock charging handle breaks. The RS one already has a hole in it, perhaps the front part of it can be dremeled to spec where you can just add one of the prime buffers to it?

 

The bolt face comes in contact with the hop up unit before it comes in contact with the molded barrel extension. If you look at the bolt carrier, it does not come close the ejection port all the way. The contact points of the bolt carrier group are the sides, back, bolt face, and bolt handle catch....the front area of the bolt carrier does not come in contact with anything. At least it should not as if it did, you are pounding on your upper receiver.

 

 

Luis-

 

I had the feeling that the AS bolt carrier group is the same one that the G&P WOC's use. The bolt and bolt carrier has the same color on them as the ones installed in the G&P. One of my friends in California has one and claims he has fired over 3k rounds through his bolt carrier assembly on green without any problems.

 

I have also purchased a separate AS bolt/ loading nozzle to be used on my AS light weight bolt carrier so I will have 2 BCG's to play around with . Should any of them break part number 2, I still get to have the stock AGM one as replacement...I should be set. Hopefully.

 

The main reason why people got their AGM M4 GBBR is that its cheap. I'm trying to find the cheapest but most reliable set up possible. If push comes to shove and I just end up with broken BCG's, I just have to spend another 300 bucks on an RA-Tech NPAS BCG. Until then, I am hoping for the best with the parts coming in

---------------

 

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Jul 20, 2009 7:42 PM

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Jul 20, 2009 11:48 AM

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Jul 17, 2009 11:37 PM

Shipment information sent to FedEx

 

 

AS Bolt Carrier w/ Loading nozzle, and AS Bolt (Loading nozzle) is inbound. Hope I get my hands on it the next couple of days

Edited July 20, 2009 by sacairsoftsn00py

[KWP]

The new 5KU mags weigh 630g and are said to not leak on Green gas.

Is that a bolt stop selector switch?

 

http://www.ebairsoft.com/metal-50rds-magazine-p-2377.html