AGM M4 GBB

[jonny2400]

http://www.waridiot.org/index_eproduct_vie...?products_id=87

 

5 WA M4 mags 129 USD... thoughts

 

http://www.airsoftireland.com/forums/index...c=16360&hl=

 

 

Edited July 5, 2009 by jonny2400

[Stealthbomber]

thanks stealth, now i'm stuck on another problem, I can get all the other pins out, but i can't get no 213 out, because it's a hollow type pin... anyone know how to punch out this type of pin?

Well....

 

A "proper" punch (or "drift" as they're properly called) for a roll-pin is usually dual diameter. The point is thin enough to slip through the middle of the pin (which locates the drift centrally) and the rest is a diameter slightly smaller than the pin.

It's far more common for a drift to simply have a flat end though.

 

If you want to do it properly you can get a set of drifts (such as THESE) off eBay pretty cheap.

Do a search on eBay for "pin drift" or "pin punch".

Obviously, make sure the set you buy is small enough to work with your pin.

 

Instead of doing it properly () I happen to have an ice-cream tub full of old jewellers screwdrivers.

I picked out 3 or 4 that have the correct diameter shaft and grind the point off with a dremel to leave me with a suitable drift.

 

If you go to a local market stall you can often pick up a horrid cheap set of chinese jewellers screwdrivers for less than a quid. Buy some and (as long as you already have a dremel - every airsofter needs a dremel!) you can make yourself a set of drifts pretty easily.

 

There's nothing special about knocking out a roll-pin.

The main thing is to use a drift as large as possible (as long as it's actually slightly smaller than the pin).

The worst thing that can happen when you're knocking out a roll-pin is that you use something smaller than neccesary.

If that happens the drift will force its way down inside the pin and this, in turn, will force the pin to stretch wider and it becomes a nightmare to remove the drift or the pin.

If this happens the best thing you can do is use another (bigger) drift to try and knock the pin out from the opposite side.

[snorkelman]

http://www.waridiot.org/index_eproduct_vie...?products_id=87

 

5 WA M4 mags 129 USD... thoughts

 

my thoughts are you're reading it wrong? its cost of one mag plus 129 USD to buy the five pack (166 dollars total)

 

seeing as its the same AGM mags that gunner are selling at 22 dollars a pop - total for five from gunner is 164 shipped HK airmail (which is what waridiot include as their inclusive postage method) or 177 shipped EMS from gunner (which war idiot would want 186 for) then it just seems the usual going rate give or take a dollar or two

 

bolt carier group

far as bolt group goes I'm getting on OK with the complete RA-tech WA steel bolt carrier group. bolt carrier on that is the steel part while the 'nozzle and bolt' assembly inside it is cnc'd alloy. Overall weight for that is 242 grammes versus 206 grammes for the standard AGM bolt carrier group so I work that out as being just under 20 percent heavier.

 

Preflight check on that unit would be:

 

Dump the original Ra-T red oring from the piston - its a bit soft and 'grabby'

Check and make sure the thru pin just in front of the oring (that holds the bolt into the nozzle housing) is fully seated and not poking out at one end

Make sure the aluminium side plate is in place and not binding the runner on side of the nozzle housing

Give it a little silicon oil around oring

check and make sure that the nozzle n bolt part snaps back into place nicely under its spring tension when you draw it out from the carrier and let it go, and its good to go

 

CO2 mags

I'd like to see CO2 mags out too - sure unregulated CO2 is 850 PSI but there isnt a single airsoft gun running that directly out of their mag, all the CO2 mags throttle down the output PSI supplied to the gun from the mag. Theres no physical reason that throttled output pressure couldn't be equiv of propane - its just that most of them feel obliged to set that output pressure higher than what propane would provide.

 

Option of a co2 mag with propane levels of pressure output (or just a little higher) would be ideal IMO. It's never going to beat straight bottled propane in price stakes, but you'ld get similar running costs (maybe slightly cheaper) than running green gas, with a lower temperature floor (and none of the pong you get with commercial propane that always makes me want to puke).

 

Maybe GHK will do one at some stage - their mag design would make it relatively easy to accommodate a caplet and crude pressure reg (a wee bit more awkward than their CO2 AK mag but not much) and they've already got experience of restricting output pressure on CO2 mags from their AK mag work.

 

hop up

Got chance to try mine outdoors today overall range was good but was fair bit of overhop with Red Ra-tech rubber and Ra-tech hop chamber, so on getting back home I ended up fettling the actuating lever to reduce the pre-engagement (size of the nubs, top surface of the lever from pivot point back to the spring so it can pivot higher inside the hop unit, and lower bottom face of the lever at the adjuster end, where it would bottom out against the inner barrel). Not likely to be an issuie if running the AGM rubber and AGM hop unit.

 

On going back out with it I was still getting a slight curving up, but none of the 'reach for the skies' it was producing earlier so I've now fettled it a teeny bit more (just wont be able to test that till later in the week now)

 

drifting out roll pins

if I havent got punches to hand my prefered method is to find a scrap drill bit thats same diameter as the pin (large enough not to go thru it, small enough to clear the hole the pins in) and use the shank end of that against face of the roll-pin. Then just tap the pointy end of the drill bit with flat side of a pair of pliers to get it started

Edited July 5, 2009 by snorkelman

[stew_b_10]

http://www.waridiot.org/index_eproduct_vie...?products_id=87

 

5 WA M4 mags 129 USD... thoughts

 

http://www.airsoftireland.com/forums/index...c=16360&hl=

 

looks like we need a guinea pig...

[Stealthbomber]

drifting out roll pins

if I havent got punches to hand my prefered method is to find a scrap drill bit thats same diameter as the pin (large enough not to go thru it, small enough to clear the hole the pins in) and use the shank end of that against face of the roll-pin. Then just tap the pointy end of the drill bit with flat side of a pair of pliers to get it started

To put my trianspotting health & safety hat on for a moment...

 

You probably shouldn't be using s drill bit as a drift. The metal should be hardened to the point where it could shatter and send splinters of drill bit all over the place.

Even if it doesn't shatter a drill can crack sharply and if you happen to be holding it at the point where it cracks you could end up with a lump of drill bit stuck in your thumb.

 

To be honest, with the amount of cheap & nasty drill sets on the market these days (usually those gold coloured drill bits) this isn't a huge concern but, as a rule of thumb, you shouldn't be using a drill-bit as a drift.

[snorkelman]

aye maybe so but Ive never had a problem in twenty seven years of doing it

[Luis21]

Okay guys,

 

I finally got my hop-up fixed.

 

The initial problems were:

 

- The hop-up arm wasn't putting enough downwards pressure on the hop-up bucking.

 

- The force from the bolt face going forward to chamber the BB was greater than the pressure being put on by the hop-up.

 

- The bolt face nozzle/flute valve isn't too long. I fitted the nozzle into the hop-up rubber and it only went in aabout 3-4mm.

 

- The nub inside the hop-up rubber was way too short to fully come down to put a good backspin on the BB.

 

- When adjusting the hop-up, I wouldn't see a diffrence between the lowest and highest setting.

 

- The BBs were getting chambered way too hard past the chamber. You would be able to shoot them out if you fired fast enough they rolled out. However since they were already past the hop-up, they weren't getting any backspin at all. This affected accuracy as well as range. Not good.

 

The solution:

 

- I added matter to the top of the hop-up rubber so more pressure would be put downwards by the hop-up arm.

 

- The hop-up now puts enough pressure on the BB to get a good grip when it's being chambered by the bolt face.

 

First, I put a thin coat of silicone glue on top of the hop-up rubber where the hop-up arm pushes down.

 

 

I then cut out a piece of electric tape about 2cm in length.

 

 

Finally, I wrapped the tape on top of the silicone glue coat on the hop-up rubber. Not too tight, just enought to hug the rubber.

 

 

As of now, the BBs don't roll out of the barrel anymore whatsoever. Not even on the lowest hop-up setting. I haven't tested range and accuracy with this new mod but it shouldn't be bad at all. It should be an improvement since my hop-up can actually put a good backspin on the BBs now.

 

I heard that some people had masking tape on their hop-up rubbers straight from the factory. These people didn't have the problem with BBs rolling out of the barrel.

 

I was going to file down the flute valve but I decided not to mess with the gas chamber and its compression. Plus I've filed down too many things on this gun already.

 

After this mod, the hop-up rubber is going to be a tiny bit tighter. Don't be concerned, this will allow it to grip the BBs better.

 

-Luis

Edited July 5, 2009 by Luis21

[snorkelman]

I was going to file down the flute valve but I decided not to mess with the gas chamber and its compression. Plus I've filed down too many things on this gun already.

 

when set up as an NPAS setup as the AGM uses it, the front section of the flute valve doesnt need any real length, it has no bearing on compression etc in that config, instead its only use is to stabilise the valve disc in the chamber (and provide something to shove inside the spring to centre it too) - if you look at the RA-tech variable one you can see the stem is really short.

 

It only needs to be its full length when in a PPS system, as the valve disc is held open in the chamber by pressure of the BB against the flute. Rest of the time its closed as the spring sits behind the disc in that setup (pushing the valve disc and stem forwards). So on a PPS you should only be able to seat a BB against the nozzle when you apply pressure on the BB to force the flute valve in.

 

Where it would need to be cut down is in following circumstances - in an NPAS config when its so long that when placing a BB against it and the nozzle the BB doesnt seat evenly against the rim of the nozzle, but instead actually rests on the point of the valve stem.

 

Now by default it shouldnt be that long on the AGM but if folks opt to shim the valve disc to bring it closer to the nozzle to reduce FPS, then the valve stem will obviously be sitting further forwards too and it may start to poke out far enough to cause that 'resting on point of the valve stem' issue.

 

[Luis21]

when set up as an NPAS setup as the AGM uses it, the front section of the flute valve doesnt need any real length, it has no bearing on compression etc in that config, instead its only use is to stabilise the valve disc in the chamber (and provide something to shove inside the spring to centre it too) - if you look at the RA-tech variable one you can see the stem is really short.

 

It only needs to be its full length when in a PPS system, as the valve disc is held open in the chamber by pressure of the BB against the flute. Rest of the time its closed as the spring sits behind the disc in that setup (pushing the valve disc and stem forwards). So on a PPS you should only be able to seat a BB against the nozzle when you apply pressure on the BB to force the flute valve in.

 

Where it would need to be cut down is in following circumstances - in an NPAS config when its so long that when placing a BB against it and the nozzle the BB doesnt seat evenly against the rim of the nozzle, but instead actually rests on the point of the valve stem.

 

Now by default it shouldnt be that long on the AGM but if folks opt to shim the valve disc to bring it closer to the nozzle to reduce FPS, then the valve stem will obviously be sitting further forwards too and it may start to poke out far enough to cause that 'resting on point of the valve stem' issue.

 

Thanks for the highly useful info Snorkel. I'm sure others will appreciate it too.

 

-Luis

 

[stew_b_10]

Luis,

 

Are you sure you didn't have the adjuster ring on wrong? when you do, you don't get any hop, but when its on correctly (the 'thinner' side of the little 'tabs') it appears to operate just like my AEG hops, and i can see the difference just looking into the hop.

[snorkelman]

your welcome, only thing I should add is

 

a - cutting a little is as good as cutting a lot. Altough it can be pretty short theres never going to be a need to cut any more than two to five mill off of it at most

 

b - soon as you cut it its no longer going to be long enough to use as a positive pressure flute valve ..though as it works fine as a negative (and can be shimmed as per MDKs instructions to reduce FPS) I cant think of any real reason why anyone would want to swap it over to PPS layout

Edited July 5, 2009 by snorkelman

[Luis21]

Luis,

 

Are you sure you didn't have the adjuster ring on wrong? when you do, you don't get any hop, but when its on correctly (the 'thinner' side of the little 'tabs') it appears to operate just like my AEG hops, and i can see the difference just looking into the hop.

 

Yes, I analyzed the hop-up dial and how it works. It's a tapered design. I had it the right way too, but no matter how I adjusted it it didn't make a diffrence. For me at least.

 

@ Snorkelman: Thanks again for the little extra tips. I'm sure they'll come handy in the future.

 

Thanks,

 

-Luis

[Luis21]

Big update guys!

 

In order to fix the issue with the BBs rolling out of the barrel, don't do the guide I posted a couple posts up. After testing it, the BBs started to roll out again and the gun was over hopping the BBs.

 

Instead cut about 5-7mm off the tip of the flute valve. The litttle 3 pronged valve that you can see by looking into the loading nozzle. After cutting off a bit off the flute valve, put a BB on top of the loading nozzle and make sure it's perfectly seated on the nozzle.

 

Then just wrap a bit of electrical tape only around the hop-up rubber and the BB pissing should stop immediately, no matter what hop-up setting it's on.

 

My gun is ready now, I just need magazines.

 

-Luis

 

P.S. Big thanks for the suggestion Marshal.

[Spencerman]

Oh well, it was as I dreaded. I have just tested out the firing of this gun, and I have the drippy bb problem. Any chance that someone can illustrate the cure as described on the previous page please, as I dont quite follow it and wouldnt like to ruin the part.

[MDK_Marshal]

Quite simple... You just remove the floating valve from the nozzle, and chop the front down a couple of mm. Stops the BB rolling off the nozzle when placed upon it; This means that the BB is being pushed by the nozzle, and not by the floating valve.

[muckymick]

when i first got mine the bb's did fall through the hop up and out the barrel so i took the barrel and hop unit apart to find that the barrel was upside down and the hop rubber was fitted in the hop chamber wrong.I reasembled it correctly , now every thing work as it should and the bb's no longer fall out the barrel

[Downslide]

MDK - I think by "Illustrate" he meant, "take a picture of," but I could be wrong.

 

This thread is fantastic as far as information goes. I am going to see if I can snag an hour or 2 to go thru it this week and pull all of the tips n tricks out, and condense it into one thread, or at least pop a glossary of links to the respective posts.

 

Also, has anybody found a translated parts list/ schematic of the AGM? My Chinese is well, non-existent.

[falconfour4]

I got a few more bits from ebaybanned today.

 

The aluminium speed buffer is actually a hard recoil buffer, it is very well made, the same length as the AGM factory fitted buffer and it has a loose weight inside it to increase recoil, it actually works quite nicely.

 

I also got another set of anti rotation links, and this time the screw threads are all ok, if anyone can write a guide on how to fit these i would be most grateful.

 

Lastly i got one of these http://www.ebairsoft.com/style-rail-carbine-p-2185.html (daniel defence 9.5 fsp rail)

i emailed ebaybanned before i bought it to check that it would fit the AGM M4 and of course they advised that it would no problem.

Surprise surprise it doesnt, the threaded barrel nut doesnt even reach the threads on the body. either the bottom of the barrel is too thick or i am doing something wrong (a DD fitting guide would be nice ).

I dont really want to start grinding away at my barrel so i have put the old RIS back on for now which is a shame because the DD rail would look awesome.

[ruchik]

Well I figured out how to stop the damn o-ring from unseating on the valve shaft. And to somewhat fix the wobbly barrel.

 

The barrel isn't attached to the receiver by anything other than two slots that fit into two nubs. The delta ring tightens over both the barrel and the receiver to hold them together. Wrapping teflon tape around both the base of the barrel and the receiver, then tightening the delta ring over works awesome. Very slight wobble, but unnoticeable when handling, unless you grab the barrel and shake it about.

 

The valve seal is a little trickier. You have to wrap teflon tape around the o-ring, and the part of the shaft just in front of the o-ring, NOT behind the o-ring on the main body of the shaft. If you do, the silicon lube gets under the tape and loosens it, then the gas pressure just rips it apart. By making sure only the o-ring and the small area in front of it is covered in tape, when the brass plug goes over the o-ring, you get a tight fit and nothing gets the chance to loosen up. The original problem is that the o-ring is just too loose, and pops out from under the brass cap eventually.

 

And I keep saying it, but the PGC hopup chamber is ace. It's exactly the same shape as the original, comes with an excellent rubber, AND allows you to use AEG barrels, without any mods at all. The original WILL break fairly soon, the PGC is reinforced. Also does not exhibit the BB's rolling out symptom.

Edited July 6, 2009 by ruchik

[beretta]

The body pins just push out. have the hammer cocked when ya do it though, it'll hold together better. the pin with the screws is the hammer axel. just push them into place and when both are in, attach the links to the pin head on one of the body pins and the other end of it has a hold for the screw. this'll screw straight into the hammer axel pin. i just did it a few mins ago and it literally took 2 minutes. all you need is allen keys.

 

I got a few more bits from ebaybanned today.

 

The aluminium speed buffer is actually a hard recoil buffer, it is very well made, the same length as the AGM factory fitted buffer and it has a loose weight inside it to increase recoil, it actually works quite nicely.

 

I also got another set of anti rotation links, and this time the screw threads are all ok, if anyone can write a guide on how to fit these i would be most grateful.

 

Lastly i got one of these http://www.ebairsoft.com/style-rail-carbine-p-2185.html (daniel defence 9.5 fsp rail)

i emailed ebaybanned before i bought it to check that it would fit the AGM M4 and of course they advised that it would no problem.

Surprise surprise it doesnt, the threaded barrel nut doesnt even reach the threads on the body. either the bottom of the barrel is too thick or i am doing something wrong (a DD fitting guide would be nice ).

I dont really want to start grinding away at my barrel so i have put the old RIS back on for now which is a shame because the DD rail would look awesome.

[falconfour4]

so when i knock the old pins out i wont have any springs flying off no?

[the hot tuna]

I will purchasing one next week and I need some info-

 

I'm trying to run on a budget of less than $300 USD and I want this thing to run smoothly. I've read through most of the threads and have found some info here and there, but I was wondering if someone could put up a list of links to go to for upgrade for the AGM M4.

 

Links for-

 

-must have upgrades when first purchasing.

-upgrades to consider.

-Metal body kits.

 

Basically I'd like to have links to everything that you could put on the AGM M4. Also, is the aluminum hop up chamber from Ebaybanned worth getting?

 

 

 

thanks, Holt.

Edited July 6, 2009 by the hot tuna

[beretta]

so when i knock the old pins out i wont have any springs flying off no?

 

Nope, nothing will pop out on ya, what i did though was to press them out with an allen key and follow through with the allen key so everything is still held in place. then with the new pin you just push it in as you are pushing out the allen key. i had the lower receiver removed from the upper at the time too.

[3vi1-D4n]

Here is what I had to do to a few of the ones my team mates and I bought (ours is the original 061), these are all mods out of the box.

 

- Add tape to the hop rubber so BBs don't fall out (20 Mins)

- Clean the barrel (1 min)

- Modified the bolt catch (30 mins)

- Loose barrel nut mod due to a worn receiver thread (One of the M4 only) (15 mins)

- Modified the bolt face and hop unit so it doesn't destroy the hop unit (preventative measures - 15 mins)

- Bolt carrier reinforcement (replaced one of the pins on the bolt with a screw) (15 mins)

 

The original mag is dead but the spare mags don't leak at all.

 

I also modded the selector switch so it doesnt fall out, and I modded the AGM to take WE pins

 

I have both the WE and the AGM. And I like both guns. Both guns are equally skirmishable, but if you are on a budget the AGM is the easy choice as it has ironed out a lot of issues with the WA.

Edited July 6, 2009 by 3vi1-D4n

[the hot tuna]

3vi1-D4n you have a PM.