AGM M4 GBB

[Pablissimo]

You can't legally buy 134a in the US anymore. So Duster gas is essentially the same thing, depending on the brand it might be a tad bit lower power. I stick with RadioShacks stuff because it was the best in all the tests i did a long time ago.

 

I'm debating just getting the replacement bolt set instead of the complete carrier too.

 

With all due respect, 134a is readily available in the US. I just bought a few cans yesterday. (http://www.biglots.com/specials/WeeklyAd.aspx?sid=9999&style=f)

[Roecar]

Snorkleman, you said you got your metal RATech bolt/NPAS to with with your AGM? How are the tolerances? There was another member who was having issues with his getting stuck or something like that.

[snorkelman]

how much has that all cost in total?

 

I went all spendy on it and bought parts I really didnt need, ignoring those bits the siginficant parts I'd reckon are:

 

rifle incl EMS shipping from gunners $189

 

steel bolt carrier with aluminium adjustable NPAS dim-grey $260

ra-tech hop rubber $007

ra-tech steel bolt catch $015

Inokatsu buffer $015

ra-tech plastic nozzle shell $020*

 

*I got this chucked in as a freebie but the side lock plate from it is a much smoother fit than the alloy one that comes with the steel bolt carrier assembly (if you dont mind fettling with a bit of wet and dry paper then the aluminium one supplied with the steel bolt carrier assembly will probably work out fine in the end)

 

ra-tech CNC hop up chamber $055

 

I'm torn on this part its very nicely made but.. if Ebay banned ones at 20 bucks do turn out to be OK adn stealth just got a naff one they might be a better option, add to that the original AGM one is a pretty 'nylony' style plastic (ie has a bit of flex to it and not super hard) which I dont see breaking anytime soon (more likely to chew up than crack) No matter which one you buy you end up using the AGM actuating lever and the AGM adjustment drum, its only the main body of the hop up you're getting for the dough..

 

So at moment Im going to stick my neck out and still recommend the RA-tech one (at least untill I get chance to test rifle again tomorrow using RA-tech hop rubber along with the AGM hop unit) if the AGM unit turns in similar performance then Id be inclined to stick with it and just change the rubber.

 

With RA tech hop unit $561 total incl shipping

 

Without RA-tech unit $506 incl shipping

 

 

Add cost of mags to that (I went with GHK at 50 bucks a pop)

 

The other parts I bought not included above would be steel trigger, steel selector, steel mag catch, spare hop rubbers, spare orings, different strength buffer tube spring (not used yet) etc.

 

[snorkelman]

Snorkleman, you said you got your metal RATech bolt/NPAS to with with your AGM? How are the tolerances? There was another member who was having issues with his getting stuck or something like that.

 

its around a mm longer or so overall but not had any issues with it sticking in the receiver or the buffer tube wether in semi or auto - currenty running it with standard AGM spring (looks to be equiv of RA-tech winter spring) and an Ino buffer. Receiver can still close with it fitted.

 

Only issues I did have with it was the aluminium side lock plate and the red oring - whenever I drew the nozzle block/bolt out of the bolt carrier and let it go it didnt snap back into place - instead it slid back in at a crawl. I swapped side plate over for Ra-tech plastic one (it fits more loosely) and swapped the red Ra-tech o-ring for the stock AGM black one, smeared a little lube over inside of the bolt carrier and popped it back together - when I daw the internals out now they return pretty snapilly

 

One thing thats going to differ on mine is at moment theres no paint on the receiver - its been chemically stripped down to metal inside and out in prep for repainting. However seems plenty of tolerance between I/D of the receiver and O/D of the bolt (even allowing for a thick coat of paint inside receiver).

 

Only 'rubbing' marks I'm getting on the steel carrier is along bottom from the hammer being cocked

[ruchik]

I do recommend the PGC hop up chamber. Its a very sturdy ABS plastic, much like the reinforced nozzles for GBB pistols made by Shooters Design and Guarder. Also comes with a new hopup rubber. It's a tight fit, but it also allows the use of normal AEG barrels, which BTW do fit into the stock AGM barrel. If it doesn't seem like it wants to go into the barrel, just push it in harder.

[snorkelman]

one thing I forgot to mention is recoil and noise in comparison to escort guns that I think some folks were looking to get feedback on

 

It definately kicks harder than my Shoei MG42, Escort MP5 (standard and A-spec), M60 (standard) and SP M16s (more or less standard and a fully ASL upgraded one)

 

I'd put it on par/slightly edging my standard Shoei MP44 for kick and for metalic clinks and clunks

 

where it wins out over all of them incl the MP44 is in sheer overall noise - with the escort system being much more of a sealed system the gas all tends to go down the spout, whereas on these theres a bundle of it down the spout and a bundle of it released around the bolt area as the gun recoils

 

only equivalent GBB gas in mag design I've got is the GHK AK and its far louder (and kicky) than it too.

[Luis21]

Okay guys, yesterday I installed the whole set of Inokatsu lower reciever parts. I also got some duster.

 

The Inokatsu lower reciever parts set fit great. Everything was a drop in fit except the firing block. Be prepared to file/dremel the inside of the lower reciever a bit and a chunk off the Inokatsu firing block.

 

***When installing the Inokatsu hammer or any other hammer for that matter, make sure you use the stock AGM hammer spring. Other brand springs don't have enough tension to press in the magazine valve to release gas. So USE the stock AGM hammer spring when using AGM magazines.*****

 

 

 

Here's the right side of the stock firing block. The face with the grey pin is completely flat. The Inokatsu counterpart is a bit raised, you need to file that little mound down.

 

The Inokatsu parts are solid and very well made. Trigger pull is way smoother now. Hopefully I won't have to change the parts out ever again or for a while.

 

Also, the little steel bit, located on the bolt carrier where it engages with the bolt catch, fell off. Once I got the gun to lock back every single time, the steel bits on both the stock bolt carrier and bolt stop fell off. They're not secured properly and will fall out with extended bolt lock back cycles. Those pieces fell off within 1000 rounds in my gun.

 

I had to file down a rectangular portion so the Inokatsu bolt catch can engage the bolt carrier for right now. If I don't replace the bolt carrier soon the Steel Inokatsu bolt catch is going to rip it apart.....

 

 

 

Also, in order to cycle correctly, the right underside of the bolt carrier has to be filed down significantly since the Inokatsu bolt catch is a bit higher than the stock one and it rubs against the bolt carrier.

 

 

I finally went out and shot the gun properly. The power is nice, however the accuracy is terrible. The hop-up is terrible, I adjusted it and still the results were terrible. Even on the highest setting, the BBs would curve down at about 30 meters..... I was also using .2g BBs.

 

I need to clean the bucking and the barrel, hopefully that'll solve the accuracy issues and the BBs rolling out of the barrel. I also feel that the hop-up arm isn't putting enough pressure on the BBs, I might have to add material to the arm so it pushes on the BBs more.

 

I used duster and DO NOT recommend it at all. The blowback is the same, however it cools down more than propane and the ROF on full auto is about 1 RPS. I can shoot semi faster than that. The BBs still roll out the barrel using duster.....

 

One thing, when my magazine was fully filled, the valve knocker wasn't strong enough to release the gas. I need to lube the mag valve.

 

I wish I had a dremel right now, would of saved me so much time, but carry on.......

 

-Luis

Edited July 3, 2009 by Luis21

[falconfour4]

its around a mm longer or so overall but not had any issues with it sticking in the receiver or the buffer tube wether in semi or auto - currenty running it with standard AGM spring (looks to be equiv of RA-tech winter spring) and an Ino buffer. Receiver can still close with it fitted.

 

Only issues I did have with it was the aluminium side lock plate and the red oring - whenever I drew the nozzle block/bolt out of the bolt carrier and let it go it didnt snap back into place - instead it slid back in at a crawl. I swapped side plate over for Ra-tech plastic one (it fits more loosely) and swapped the red Ra-tech o-ring for the stock AGM black one, smeared a little lube over inside of the bolt carrier and popped it back together - when I daw the internals out now they return pretty snapilly

 

One thing thats going to differ on mine is at moment theres no paint on the receiver - its been chemically stripped down to metal inside and out in prep for repainting. However seems plenty of tolerance between I/D of the receiver and O/D of the bolt (even allowing for a thick coat of paint inside receiver).

 

Only 'rubbing' marks I'm getting on the steel carrier is along bottom from the hammer being cocked

 

Hey snorkleman, wouldnt be interested in selling me your AGM side lock plate would you?

I really need a replacement

[snorkelman]

Hey snorkleman, wouldnt be interested in selling me your AGM side lock plate would you?

I really need a replacement

 

you have PM

[Luis21]

One more thing. When installing the Inokatsu bolt catch you have to cut off 5 coils off the bottom spring so the bolt can still lock back. The spring is too stiff and won't allow the bolt to catch, not even with like 20 BBs using my spring mod.

 

So bottom line, cut off 5 coils and it'll still lock back with my mod using the standard 8 BBs.

 

-Luis

[Badly Browned]

Happen to know what its like with 3rd party magazines?

Edited July 3, 2009 by Badly Browned

[Luis21]

Happen to know what its like with 3rd party magazines?

 

Not at all. However those 3rd party magazines better have springs with Hercules strength because the full length spring is way too stiff out of the box. If you cut the 5 coils, the AGM mag, modded with the 8 BBs can still activate the bolt catch. Yet, the spring still puts enough pressure on the bolt catch so that it doesn't move around and catch on stuff; it stays in place.

 

-Luis

[Stealthbomber]

The spring is too stiff and won't allow the bolt to catch, not even with like 20 BBs using my spring mod.

 

Sorry, I don't mean to be picky but.... your spring mod?

 

Allow me to quote myself from earlier in this thread:-

The only way to increase the spring tension is by either replacing or pre-tensioning the magazine spring.

Maybe, as with midcaps, the thing to do is fit something behind the spring to compress it slightly?

 

Even so, people have been shoving BBs, or other things, behind the springs in mags for god-knows how long so a little less of the whole "your idea" thing would be a lot better.

[Luis21]

Sorry, I don't mean to be picky but.... your spring mod?

 

Allow me to quote myself from earlier in this thread:-

 

 

Even so, people have been shoving BBs, or other things, behind the springs in mags for god-knows how long so a little less of the whole "your idea" thing would be a lot better.

 

Well it is mine, it has my name on it, and I can even show you the certificate with my name on it.

 

But in all seriousness, I put "my mod" because I was reffering to the guide I posted up like 2 pages ago.

 

But yeah, like you said, it's a well known concept. So well known that its origin is forgotten.

 

-Luis

[jonny2400]

Guys I have been thinking of fitting this to improve recoil!

 

http://www.redwolfairsoft.com/redwolf/airs...il?prodID=26864

 

Any thoughts or warnings?

 

 

 

Second, How do you get the hop up out. As BB are also rolling out of mine, between shots.

 

Third am still not happy with the MKII AGM lightweight mags. They have not loosed up a bit, Its a big job just fitting & removing the damn things. I am going to sand paper the inside of the mag well and also order a GHK mag to compare. As it is I could not use it to play airsoft, when its a two hand job to change mags.

[Roecar]

Don't ask me how I did it but my GHK mags literally fall out without any friction with a simple tap of the mag release. No tugs, bugs, or fusses. I honestly can't tell what I did by accident to do this but even before this happened out of WA mags (tried in store), the AGM mags, and my GHK mags, GHKs fit the best and were the easiest to remove.

[jonny2400]

Just done the mag well, What a different 10 mins and some sand paper makes The mags now glide in and drop right out, once I hit the mag relase button...Just like an AEG lol

 

Had a look at the Hop while I was at it. I take it a new a special tool to move the delta ring, to check the hop

Edited July 4, 2009 by jonny2400

[MDK_Marshal]

Had a look at the Hop while I was at it. I take it a new a special tool to move the delta ring, to check the hop

 

Generally a specialised tool is preferable to save mangling the nut; You can do it with pliers, bit this is liable to damage the nut and make it look nasty. You can buy one for about £20/$20 (cheaper in the US...), or you can just make one. I was tired with not having a proper tool to use, and made one out of a bit of wood and a few bolts with the threads filled off. Works like a charm.

[Kn1v3s]

Yeah it fits very nicely, theres absolutely no play in the stock on the standard AGM stock tube. it fits better than pretty much any other rifle ive had the MOE stock on.

 

 

 

I got myself the Magpul hand guard as well. Did you have difficulty removing the front sight? I'm having a tough time just getting that sight off so I can put the hand guard. Did you remove the sight or just ripped that plastic off so it can fit?

[Stealthbomber]

What'd you mean you're having a tough time?

 

You hammer the 2 pins out and the sight slides off.

 

There IS a threaded hole hidden underneath the sling loop but it doesn't seem to have a grub screw in it.

If you're struggling to remove the front sight, knock the pin out that's holding the sling loop in place and check there's no grub screw in there.

[raito]

guys i've got a problem with my mag, the mag was just sitting there when suddenly it started venting gas out... now every time i fill it up the gas just comes out of the top...anybody know of any solution to this?

[snorkelman]

What'd you mean you're having a tough time?

 

You hammer the 2 pins out and the sight slides off.

 

There IS a threaded hole hidden underneath the sling loop but it doesn't seem to have a grub screw in it.

 

mine has the grub screw (though rather it didnt to be honest - just one more thing to have to knock a split pin out to reach)

 

guy who built yours was definately in a hurry to break for lunch

 

 

[Badly Browned]

guys i've got a problem with my mag, the mag was just sitting there when suddenly it started venting gas out... now every time i fill it up the gas just comes out of the top...anybody know of any solution to this?

 

Check all the orings in your valve.

[Spencerman]

I am exitedly looking forward to getting one of these now, I should be picking mine up tomorrow. Initially I wanted a WE model, and for some reason I do still want one of the latter WE models, as there is something that I seem to prefer about the system that it uses. Anyway, the only thing that really worries me so far about this agm cheapy gun is the problem with the premature discharge of the bb from the end when the gun is pointing downwards. I have read and read but didnt see whether someone has identified the cause and the solution of this problem. Anyway, that is not the reason that I was posting, I have a question.

 

I have read somewhere between one of the many gbb threads and hundreds of pages containinf thousands of posts about how to increase the felt recoil of the gun. If my memory serves me correctly it was something along the lines of a couple of spacers put into the buffer tube or something, which drastically increased the felt recoil. I couldnt find it again now, and wondered if anyone did indeed know how to increase the felt recoil so that it feels more like a hard punch in the arm rather than a limp wristed tap on the shoulder? A few posts up there was the question raised about an aluminium buffer to increase the recoil. I wondered if too if this would be case, as surely it would need to be heavier to increase the felt recoil? I do not want to increase the actual recoil of the gun via the speed of the bolt travel or anything like that. Hope someone can help.

[Luis21]

I am exitedly looking forward to getting one of these now, I should be picking mine up tomorrow. Initially I wanted a WE model, and for some reason I do still want one of the latter WE models, as there is something that I seem to prefer about the system that it uses. Anyway, the only thing that really worries me so far about this agm cheapy gun is the problem with the premature discharge of the bb from the end when the gun is pointing downwards. I have read and read but didnt see whether someone has identified the cause and the solution of this problem. Anyway, that is not the reason that I was posting, I have a question.

 

I have read somewhere between one of the many gbb threads and hundreds of pages containinf thousands of posts about how to increase the felt recoil of the gun. If my memory serves me correctly it was something along the lines of a couple of spacers put into the buffer tube or something, which drastically increased the felt recoil. I couldnt find it again now, and wondered if anyone did indeed know how to increase the felt recoil so that it feels more like a hard punch in the arm rather than a limp wristed tap on the shoulder? A few posts up there was the question raised about an aluminium buffer to increase the recoil. I wondered if too if this would be case, as surely it would need to be heavier to increase the felt recoil? I do not want to increase the actual recoil of the gun via the speed of the bolt travel or anything like that. Hope someone can help.

 

I'm currently working on getting the problem with the BBs rolling out of the barrel solved. I think it has to do with the hop-up.

 

As for recoil, there are several ways to increase it. Personally the stock recoil is weak on propane.

 

To increase felt recoil you can:

 

1) Run it with red gas/Co2

2) Get a heavier buffer(more weight= more energy towards your body)

3) Stiffer buffer spring for snapier recoil

4) Speed buffer spacers

5) Heavier bolt carrier (a combination of an aluminum nozzle and a stee l bolt carrier. You can even add a bit of weight to the back of the BCG.)

6) Polish the bolt and the inside of the upper reciever to let the bolt carrier glide smoother and faster.

 

I think that's it. Since the gun isn't using gunpowder, were kinda limited to what we can use.....

 

-Luis