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Since when does post count show anything about..... blah...blah....blah....just my .02

 

Since when is it neccesary to whine about one bit of questionable humour when used as a reply to another questionable bit of humour?

 

Try listening to THIS.

Pay particular attention to the section about the Amityville movie. ;)

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Stew thanks for the support. And in away your right and wrong. while i don't have alot of helpful post I have been playing and working close with alot of heavy hitters in the airsoft industry for about 12 years and with any of my issues can go straight to them for any help needed but the agm is new and I am the first to have one out of them and have not taken mine down yet . I always try to help if i can I am that type of person . But I work in a dispatch department where all we use is caps and when I swap to the net some time i just don't realize it . But sooner or later some one with no common courtesy in the real world. has to make me feel like an *albatross* for a innocent mistake .. but back on track .. please recommend a good bucking if anyone has found one that works with the stock hop up @ not pointed at stealth s comment more mdk marshals

Edited by HOPPERSAN
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Well, here it is folks; how to downgrade your AGM M4 with nothing more than what you'll have in your drawers! Well, if you're a tech that's used to fiddling with things, that is ;) What you will require for this is:

 

1 x AGM M4 (duh ;))

1 x Sharp knife

1 x clippers (preferable, but not realy needed)

Screwdrivers to take apart the bolt

Superglue

A handfull of 8mm shims (the wide ones)

 

Aaaand that's it! So, let's get started on this, eh?

 

So, we get ourselves the nozzle from your M4. Grab it out the bolt, I won't bother to show you how. We should then have this domajig:

 

 

Photo0008.jpg

 

 

This is, in case you hadn't figured, the nozzle.

 

Now, grab the *albartroth* end out of the nozzle, and press on the floating valve like so, to push it out backwards...

 

Photo0009.jpg

 

We're then met with the lovely sight of the floating nozzle and it's retaining thingumy, naked in all it's glory! Uh, yeah. This is what it looks like:

 

Photo0010.jpg

 

 

Now, what we do is simply fit some of the shims to the back of the floating valve, as you can see in this picture:

 

Photo0011.jpg

 

Shims are fitted from the back of the floating valve, and pushed flush with the back. The little nub thingy is generally a bit too fat to let the shims on all the way, so the knife is here to trim the nozzle so they fit on; I'm ###### at describing these fiddly things, and my phone is too terrible to take pics of it. Basically, try and get the shims on, and trim the nozzle where they get stuck. If you have a jot of common sense, you'll be fine.

 

Now, grab one of those shims and superglue it to the back of the floating valve. This has the effect of having the valve sit further forward than normal, making it close earlier, hence giving less gas down the barrel and less power; this is exactly what the RA-Tech NPAS does, only this isn't adjustable.

 

How far you want to push this forwards depends on how much you want the power to drop; I can't say how much you'll need to add, as it'll depend on what your gun is putting out, and various other factors. I have about 0.9mm of shims on mine, but my chrono is being ghey and not giving me a decent reading; that, and I have horrible consistency issues. So, I can't say how much you'll need. at a rough guess, try 0.6mm or so and go from there.

 

Now, the keen-eyed (and those with memory) would notice I mentioned clippers, and I've not mentioned them in this guide. Well, this isn't technically related to toning down the power! The use for these is cutting down the floating valve for more consistency. Even stock, a BB will tend to roll off the nozzle onto other parts of the bolt face; try it with a stock nozzle, especialy after this mod.

 

What you want to do is trim the bit of the nozzle that protrudes towards the front of the nozzle, so that it sits a couple of mm inside the nozzle, and allows a BB for sit properly on the gas port thingumy. As long as there's enough for the spring to sit on, you should be fine.

 

What this does is improve the feeding a bit; the BB;s no longer get pushed by the floating valve, and ONLY get pushed by the nozzle. As far as I can tell, this should improve the consistency somewhat, and maybe eve stop BB's rolling out the barrel! Can't hurt, at any rate!

 

So, there you have it. A cheap and dirty way to downgrade your AGM to sensible (for the UK) levels! Basically all you're doing is making the floating valve sit further forwards, using dirt-cheap AEG shims to do so. I recommend getting whichever brand has the thinnest 8mm shims; the thinner they are, the finer the adjustments you can do to the power.

 

 

EDIT: Lol, copypasta button borked.

Edited by MDK_Marshal
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Since when is it neccesary to whine about one bit of questionable humour when used as a reply to another questionable bit of humour?

 

As, Ive tended to notice on these forums, pretty much whenever it suits your mood to do so. If you want to call it whining, so be it. Its your world apparently, I'm just living in it. Don't worry, ill never try and tell you your wrong. You aren't of course. Ever.

 

Just my bit of questionable humor. ;)

 

 

 

MDK, do you see any issues with adding these shims? additional wear, durability of the the floating valve with added shims, etc? how many rounds have you put through it since you first installed them?

Edited by stew_b_10
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I'm thinking that the BBs rolling out of the barrel are because the bolt face loads them with too much force into the chamber. Instead of letting the BB seat itself properly into the hop-up, the bolt face just pushes too hard past the hop-up.

 

Could this be reasonable? I'm going to manually chamber one BB and shake the gun around. If the BB rolls out, it's the hop-up, if it doesn't then that means that the bolt face is chambering the BBs with too much force during normal firing.

 

I'm also going to get some duster and see if the BBs roll out when firing with it. Maybe not because duster producer lighter blowback. It's all trial and error, I'm up for this. Anyways, as promised, I'll post up how to fix the mag in a while.

 

-Luis

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well, the bolt is going to come back with a good amount of force with any gas, fast enough at least. It may be a contributing factor, but Ill have to check it out when i get my receiver back friday before i add much useful info though.

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Ok,

 

I manually chambered a BB into the hop-up chamber and it seated correctly. I shook the gun and pointed the gun down for a good amount of time. Nothing fell out of the barrel, I checked the chamber and the BB was still there.

 

I then started firing, the next BBs started rolling out. Those BBs had been chambered by the bolt face powered by propane. I'm going to try to get some duster tonight and see what happens.

 

Conclusion: The cause of rolling BBs is caused by the forceful chambering of the bolt face powered by propane/green gas.(So far, I'm going to do more testing and come up with a final conclusion.

 

This gun is indeed a copy of a gun designed for HFC134a/Duster so these problems shouldn't be too shocking.

 

-Luis

 

Edit:

 

I'm going to get duster tommorrow. I'll post the mag guide after I eat.

 

Edited by Luis21
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I don't know if this applies to the AGM, but with my WOC when I hold the magazine higher in the magazine well then it will double feed and start to roll out of the barrel along with terrible accuracy. Just food for thought.

 

I don't think this will happen with the AGM since the mag, once locked into the body, has very little play. So even if you pushed up on it I doubt it would make the gun double feed.

 

The RS M4 jams when you push the mag up higher........

 

I guess G&P is pretty realistic in that matter :P

 

-Luis

Edited by Luis21
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yea, the AGM feed lips are quite tight. Seems as if they would be hard to double feed from. Especially as compared to, lets say, a Tanaka M700. In general, i haven't seen gas guns double feed like AEGs, just the inherent design on the feeding mechanism.

Edited by stew_b_10
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***Before you perform this mod make sure that the bolt catch in the lower reciever moves freely without getting stuck. It has to be smooth and I do recommend that you spray a bit of silicone oil to allow it to move freely. If it still doesn't move smoothly, file or sand down the little channel where the bolt catch sits.***

 

Here's my guide on how to make the magazine spring stiffer. This will allow the lever on your magazine to push up on the bolt stop with enough force to lock the bolt back 100% of the time. Before starting the mod, feel the pressure of the lever that pushes up on the bolt catch, feel it again after you're done.

 

Items needed:

 

DSC09594.jpg

 

-8 BBs

-1/16'' Pin Punch

-AGM M4 GBB Magazine

-Hammer

 

Step #1:

 

Locate the 4 pins that hold the BB channel in place.

 

DSC09595.jpg

 

Step #2:

 

Use the punch and hammer to push the pins out of the magazine body.

 

DSC09596.jpg

 

Step #3:

 

Dislodge the plastic BB channel from the magazine body and pull out the spring and its tracer:

 

DSC09597.jpg

 

Step #4:

 

Put 8 BBs down the magazine's BB "tunnel". It's the tunnel like opening in lower part of the magazine. Put the BBs in by 2's, double stacked.

 

DSC09598.jpg

 

DSC09600.jpg

 

DSC09601.jpg

 

Step #5:

 

Place the spring and the tracer back in. Make sure to grasp the spring to prevent it from springing everywhere since it will be significantly harder to put back in. While holding the spring down put the plastic BB channel back on. Make sure it clicks back onto the magazine body, with the two little prongs on the bottom facing down.

 

DSC09604.jpg

 

DSC09605.jpg

 

Step #6:

 

Push the pins back into the magazine and you're done!

 

DSC09606.jpg

 

This mod will allow your bolt to lock back 100% of the time when the magazine is empty. Both on semi and on full auto. Before the mod if you wanted to dry fire without having the bolt lock back all you had to do was flip the little switch on top of the mag. With this mod you will have to first press and hold down the black lever located in the upper back of the mag and then flip the little switch since the stiffer pressure won't let the switch work on its own.

 

With this mod the magazine now holds a total of 50 BBs(it also shoots out all of them). The bolt also locks back flawlessly when the magazine is empty.

 

I am working on how to stop the BBs from rolling out of the barrel, stay tuned for updates.

 

Please feel free to ask about anything you don't understand.

 

Thanks,

 

-Luis

Edited by Luis21
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You guys are awesome. This thread is so rich with valuable information.

 

I will try the poor-man's power downgrade. Thanks MDK_Marshal for showing how relatively simple that can be done.

Luis21, the magazine spring thingy is also nice and should solve the problem, it's a wonderful pictorial guide, easy to follow that you made, but I think I let my "gunsmith" disassemble the mags for me, I'm not a techie after all.

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You guys are awesome. This thread is so rich with valuable information.

 

I will try the poor-man's power downgrade. Thanks MDK_Marshal for showing how relatively simple that can be done.

Luis21, the magazine spring thingy is also nice and should solve the problem, it's a wonderful pictorial guide, easy to follow that you made, but I think I let my "gunsmith" disassemble the mags for me, I'm not a techie after all.

 

Thanks. It isn't hard at all to perform this but if you fell better leaving it to the tech then it's all good :D.

 

 

Thanks for the tip Luis, I'm picking up my agm tomorrow, cant wait for your other tip :D

 

No problem. I'll see what I can do about the hop-up and the BBs rolling out.

 

-Luis

Edited by Luis21
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I am just a little confused on the bolt catch bit. The way it is designed, you do not want it to move freely. There is a lock to keep it disengaged that has a audible click to it when you engage it.

 

Anyways nice guide, wish I thought of just using BBs, though it doesn't matter because my main valve keeps leaking. :( I know it's been asked already, but where would I go about getting a replacement valve? Gonna try some things to see if I can keep the o-ring for getting dislodged, but I fear it might be a losing battle.

Edited by Badly Browned
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I just finished the spring mod, but it didn't work. I can definitely feel a difference even when engaging the bolt catch manually, though.

 

I guess I'll have to try and sand the bolt catch tomorrow as was suggested then.

Edited by T0p Sp!N
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I am just a little confused on the bolt catch bit. The way it is designed, you do not want it to move freely. There is a lock to keep it disengaged that has a audible click to it when you engage it.

 

Anyways nice guide, wish I thought of just using BBs, though it doesn't matter because my main valve keeps leaking. :( I know it's been asked already, but where would I go about getting a replacement valve? Gonna try some things to see if I can keep the o-ring for getting dislodged, but I fear it might be a losing battle.

 

Yeah, it's originally designed to have the spring lock the bolt catch. However mine contains both the little spring and the detent but the spring isn't long enough to protrude out of the hole and push on the inner wall of the lower reciever. Also if the littie spring did lock the bolt catch in place it would make it even harder for the stock magazine to push up on the bolt catch in order to engage the bolt. In other words, it would only make things worse.

 

I'm going to test my modified magazine with my Inokatsu firing block which has an Inokatsu bolt stop that is locked by the spring. I'll let you guys know how it performs.

 

-Luis

 

I just finished the spring mod, but it didn't work. I can definitely feel a difference even when engaging the bolt catch manually, though.

 

I guess I'll have to try and sand the bolt catch tomorrow as was suggested then.

 

Yes, I'd definitely recommend sanding it down a bit. Not the actual bolt catch(you don't want to weaken the integrity of this part) but the actual channel where the bolt catch sits inside the firing block and the lower reciever. Lube it also. I did that prior to the mod and it works 100% of the time for me.

 

Or

 

You can also add more BBs.... Just not too many.

 

-Luis

 

Edited by Luis21
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Its more of an internal problem IMO than a magazine problem.

 

How so? All I saw was that the magazine spring didn't have enough force to push up the bolt catch up in time for the bolt to lock. That combined with a stiff or stuck bolt catch in firing block.

 

-Luis

 

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Yeah, it's originally designed to have the spring lock the bolt catch. However mine contains both the little spring and the detent but the spring isn't long enough to protrude out of the hole and push on the inner wall of the lower receiver. Also if the littie spring did lock the bolt catch in place it would make it even harder for the stock magazine to push up on the bolt catch in order to engage the bolt. In other words, it would only make things worse.

 

I'm going to test my modified magazine with my Inokatsu firing block which has an Inokatsu bolt stop that is locked by the spring. I'll let you guys know how it performs.

 

-Luis

 

Then your left with a bolt catch that can come loose during firing and partially block the bolt. IIRC, on a more realistic design there would be constant spring pressure against the bolt catch itself to keep it open instead of this weird pin & lock method. The spring on my WA magazine is significantly stronger and it engages the bolt catch just fine. The AGM magazine spring is just plain weak.

Edited by Badly Browned
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How so? All I saw was that the magazine spring didn't have enough force to push up the bolt catch up in time for the bolt to lock. That combined with a stiff or stuck bolt catch in firing block.

 

-Luis

 

My experiences with my AGM are different than yours, my mag is fully capable of activating the bolt catch without any modifications. As I said if another forum user has a positive experience with his AGM I will expand on this.

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The only way a free moving bolt will block the bolt is if it's fired upside down. Which many of you don't. It simply doesn't have enough time to block it while firing at an angle. And yes, it's all in the spring strength.

 

Fair enough Roecar.

 

-Luis

Edited by Luis21
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The bolt stop may not dislodge enough to stop the bolt, but I have no problem seeing it dislodge enough that the bolt stop is going to have to push it out of the way. Before I fixed my bolt catch, I noticed wear on my catch that looked like the bolt had slammed into the edge of the catch. Since I fixed the bolt catch, I have not noticed any additional wear on it. Perhaps it is just coincidence, and I plan to replace it with a steel catch anyways. Either way, I do not feel comfortable having something loose like that inside my rifle to mess things up inside.

 

That said, say someone does not get a lemon and/or fixes their bolt catch so it works as intended, then your part about the bolt catch is not needed. Simply a stronger spring, however way you decide to mod it, will fix most of the bolt catch issues I've seen and read about.

 

Edit: Took a look at Stealth's thread about the bolt catch in general disc, and he mentioned something about the bolt catch sticking where the pin is not involved because of the casting process. If that was what you meant by the bolt moving freely then your right, you do not want that.

Edited by Badly Browned
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On the early batch of AGM Gbb's they had a clicking pin on the bolt stop so it wouldnt engage upside down, this pin was a bit too tight for the mag to trip so in later ones they didnt insert the littls spring pin. the bolt stop is simply able to wobble in there on its own.

 

If you are having issues with the magazine not having enough spring pressure to trip the bolt catch, the most common cause of this i have seen is actually a small black part inside the magazine connected to the arm that trips the bolt catch.

The piece in question is right above the "Http" in this pic.

3672965393_349f52a57d_b.jpg

 

The left end of that is the part that sits in the magazines nozzle and the BB follower pushes it up when theres no BBs left in. the problem is though, the thickness of this part means it can get snagged inside the feeder on top of the magazine. So the spring pressure is wasted trying to push this into a tight fitting socket. take a craft knife to it, you'll only need to trim it very slightly and you'll see a big difference in how freely it moves.

 

:)

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