Want input on an AR issue

[Pete123]

I bought a Sig Sauer M400 not long ago.  I went shooting with a friend that deployed multiple times while in the service as well as being at AR enthusiast.

 

We were both shooting from a bench and he taught me that it's fine to balance a little of the guns weight on the magazine to help aim better.  

 

His guns did that with no problem.  Mine jammed on every shot.  Looking on the Internet, I read about many people who use this practice.  I called Sig customer service and was advised that the gun was fine and that AR's weren't designed to use the mag as a monopod.  

 

That response felt like a cop-out coming from Sig.  It seems to me that the military would require that to assist soldiers shooting in prone position, though I have no idea if that is the case.

 

Nonetheless, can some of you with a lot of AR knowledge weigh in on anything I can try so the gun will do this, as well as whether a quality AR should allow this.

 

The problem happened both with the Sig magazine as well as Magpul Pmag 30's.  I don't recall the ammo.  I had some PMC as well as Bargain WPA with steel casings.  The gun wasn't spotlessly clean, though had only a few rounds through it when this occurred.

 

Any input would be appreciated.

 

[Omega]

While in the service I would always use my mag at the range in the prone unsupported position with no issues.  With my civilian models I have not tried it because I am not limited any unsupported positions but I see no reason why they should have issues.  Do your mags have a bunch of play in the magwell compared to your friends AR?

[Caster]

Seems to me the issue would lie with the mag catch and/or where the magazine bottoms out inside the gun. If there is enough 'wiggle room' for the magazine to be pushed up it could touch the bottom of the carrier. If it's putting pressure against the carrier it is not gonna cycle reliably.

The top of the mag catch should hold the magazine so that it does fall out but the bottom of the mag catch should keep the magazine from being pushed further in. There should also be a shoulder inside the mag well for the magazine to bottom out on.

Try resting the weight of the rifle on a bench and retracting the bolt, feeling for any resistance. You might have to do it several times both rested and unrested to learn the 'feel'.

[gregintenn]

I do it regularly with multiple rifles, and I've about decided that I can't make an AR jam.

[musicman]

Ditto Greg. I have no military experience whatsoever, and am maybe just barely qualified to be a gun enthusiast. I've had three AR15s and one AR10 so far, and at some time or another have fired all of them with some weight/pressure being put on the mag. Never once has it caused a problem.

I don't know that I ever intentionally use the mag as a rest, but it ends up happening a lot... especially so with the 42rd promags. (Which have never caused me a problem either, btw.) As others have stated, I'd start with the mag catch. It's super easy to replace if it's a standard mil-spec design, and the parts are cheap if you just want to try something out.

[bowtieguy]

I have had several rifles that will malfunction when using the mag as a rest. Also if you pull on the mag while shooting standing it will probably cause the same malfunction.I think it has to do with the mag rocking and things interfering with the carrier. As a rule, I try not to rest the gun on the mag and use a vertical grip for when shooting standing. No reason to try to induce a failure.

[Omega]

I would NEVER use a gun for self defense, or even at the range, if holding onto the magazine will induce a malfunction. To me a gun that does that is a gun that is broken.

Same here, I've used the mag as a grip and haven't caused any issues yet.  If I'm not mistaken, there are some lowers that have what look like finger grooves in the forward part of the magwell, seems like they want you to use them like that.

[bowtieguy]

I've seen the grooves on the lower yes but not the magazine. I agree as well about not trusting a gun for self defense that acts like that. But since it has happened in the past to me, on the guns I currently own, I won't grip them that way or use the mag as a monopod. I try to always shoot the same way so if I shoot resting the gun on the mag then if I ever "need" the gun, the tendency would be to fire it that way.

I guess in my mind a screwdrivers not a chisel, a wrench is not a hammer, and the magazine isn't a gun rest.

[Omega]

I've seen the grooves on the lower yes but not the magazine. I agree as well about not trusting a gun for self defense that acts like that. But since it has happened in the past to me, on the guns I currently own, I won't grip them that way or use the mag as a monopod. I try to always shoot the same way so if I shoot resting the gun on the mag then if I ever "need" the gun, the tendency would be to fire it that way.

I guess in my mind a screwdrivers not a chisel, a wrench is not a hammer, and the magazine isn't a gun rest.

I agree about not using it in that manner if you know it has given you issues, but I would attempt to fix it as well.  You never know how you will end up firing your weapon in a defensive situation.  When ever I fire from the prone position, I find that the mag (30 round) always touches the ground in order for me to get a good sight picture.  Now I just use 20 rounders for the range, but on occasion I still use the 30 round mags but can use additional methods to elevate my position to fire properly.  

[GhostRecon21]

Sig isn't known for making quality AR's.




Sent from my iPhone using Tapatalk Edited July 27, 2015 by GhostRecon21

[Dolomite_supafly]

It's a Sig AR, stop asking for help and send it back to Sig. They are well versed on fixed their less than stellar rifles....


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He contacted SIG and they told him not rest it on the magazine. That is a failure of the gun as well as the company.

 

Imagine the one time you need it to save a life and in your excitement you grab the magazine or rest it on something, that could cost lives. Realize that ANY gun could be used to save a life so EVERY gun I own must be 100% reliable. By save a life I am not only talking about armed engagements but also hunting and that even includes 22's. If the SHTF tomorrow game will become very scarce so getting some sort of game might actually be the difference between life and death.

[GhostRecon21]

He contacted SIG and they told him not rest it on the magazine. That is a failure of the gun as well as the company.

Imagine the one time you need it to save a life and in your excitement you grab the magazine or rest it on something, that could cost lives. Realize that ANY gun could be used to save a life so EVERY gun I own must be 100% reliable. By save a life I am not only talking about armed engagements but also hunting and that even includes 22's. If the SHTF tomorrow game will become very scarce so getting some sort of game might actually be the difference between life and death.

Apparently you didn't catch my sarcastic tone.....

Sig isn't known to make quality AR's.


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[deadeye111]

Apparently you didn't catch my sarcastic tone.....

Sig isn't known to make quality AR's.


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If Sig doesn't make quality AR's I guess I got lucky because my M400 has performed flawlessly and is very accurate.  I did drop in a Timney trigger from Brownell's on sale and improved my groups.

[NashARGuy]

I can't say it a SIG that is or is not the problem because I have never owned a SIG and know nothing about them. However, I can say that your AR should not jam just by resting the mag on the ground to assist in aiming. The Mag catch should stop it from going up far enough to hit the BCG. If you have a malfunction the first thing the military teaches it to slap the mag bottom to seat the mag, rack the charging handle to eject the round and pull the trigger again. So if the mag is going up far enough to cause a malfunction then the slapping of the mag to drive it into the Bolt Group ain't gonna do noting but drive it into the bolt harder.

  I would look at the mag release and see if it is out  of tolerence. They are very cheap and easy to replace.

[jcluff]

My sig M400 Enhanced been tossed, jolted, dropped, shot in prone, rested on the Magazine and never had a problem. The only reliability issues I have had is with Tula steel cased ammo. I recommend Sig for AR-15s. All that said, what Sig told you is a bunch of crap. Have dolemite call Sig on your behalf ;-).

Seriously, I would call them again if I were you and call them out on saying that it isn't a problem with the gun.


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