Cartridges are bending?

[masterdrago]

So I'm having the exact same issue and have posted about "ejection route inconsistent" on another thread. Have had the issue for 3 years and Sig had it for 10 days, ground down the M4 feed ramps and I did not have any time to retest. Started shooting again recently. I have a lot of ammo that looks like ....



I've done everything (stronger buffer spring, H2 buffer, 5 coil heavy duty ejector spring & insert, detail cleaning, etc) so far except go to an H3 buffer and take apart the gas block piston to inspect/clean. Mine has maybe 500 rds of mixed ammo (.223 hunting, AE LC 55gr FMJBT, IMI 55gr, etc, etc) and various magazines (gen 2 & 3 PMags, D&H, Palmatto State Armory, and Tapco) and it really makes very little difference. The least failing appears to be Hornady TAP SBR 75gr which is very expensive ammo to train with. FWIW, It's a 10 piston w/suppressor set on smallest gas setting. I plan to do a few more things in trial, then put it back in the hands of Sig. Thanks to this group, I'm learning bunches.

A number of times it has done this ....

[sevignyjoe]

ok so i am waiting for a new ar stoner bcg to get here tuesday. a friend of mine is a sig armorer i am gonna try to bring it to him to at least get the feed ramps polished up in case its just roughed up.

[TomMcC]

ok so i am waiting for a new ar stoner bcg to get here tuesday. a friend of mine is a sig armorer i am gonna try to bring it to him to at least get the feed ramps polished up in case its just roughed up.

I have been away a little...why did you get an entire new BCG? Wasn't it just a possible extractor spring issue? And is "Stoner" a good BCG?

[thopkins22]

Did you ever show us a picture of the malfunction that I’m missing? 99% that the bolt carrier fixes your problems provided that it is built correctly.

[sevignyjoe]

i figured stoner started the whole thing cant be all that bad . the bcg is over all the only thing i have replaced other than the lower it self . on the gun and i got a nickle one for 125. so i will try it

[TomMcC]

i figured stoner started the whole thing cant be all that bad . the bcg is over all the only thing i have replaced other than the lower it self . on the gun and i got a nickle one for 125. so i will try it

The name Stoner today isn't even remotely related to Eugene Stoner...anymore that Armalite is related to the original. As a suggestion, if your BCG was working pretty well with other ammo and a good mag, and then starts acting up with a different ammo...look at the ammo as a possible issue. If you can weed out the ammo as the prob, then start looking at things like springs, and extractors and ejectors. It sounds to me like your BCG was essentially sound but one of those 3 things went haywire and needs attention.

[MegademiC]

So I'm having the exact same issue and have posted about "ejection route inconsistent" on another thread. Have had the issue for 3 years and Sig had it for 10 days, ground down the M4 feed ramps and I did not have any time to retest. Started shooting again recently. I have a lot of ammo that looks like ....



I've done everything (stronger buffer spring, H2 buffer, 5 coil heavy duty ejector spring & insert, detail cleaning, etc) so far except go to an H3 buffer and take apart the gas block piston to inspect/clean. Mine has maybe 500 rds of mixed ammo (.223 hunting, AE LC 55gr FMJBT, IMI 55gr, etc, etc) and various magazines (gen 2 & 3 PMags, D&H, Palmatto State Armory, and Tapco) and it really makes very little difference. The least failing appears to be Hornady TAP SBR 75gr which is very expensive ammo to train with. FWIW, It's a 10 piston w/suppressor set on smallest gas setting. I plan to do a few more things in trial, then put it back in the hands of Sig. Thanks to this group, I'm learning bunches.

A number of times it has done this ....

Did you change your extractor?

[masterdrago]

Did you change your extractor?

My extractor? Sorry I meant extractor & insert, (Tacticalsprings extra power 5 coil) not ejector. The shells extract/eject very well 99% of the time similar to the diagram I made the other day of 4 quick shots. Just at very inconsistent angles and locations. Like the OP, they fail to feed and are bent and scratched in the process about 3-5% of the time.

[the AR-15 Junkie]

The name Stoner today isn't even remotely related to Eugene Stoner...anymore that Armalite is related to the original. As a suggestion, if your BCG was working pretty well with other ammo and a good mag, and then starts acting up with a different ammo...look at the ammo as a possible issue. If you can weed out the ammo as the prob, then start looking at things like springs, and extractors and ejectors. It sounds to me like your BCG was essentially sound but one of those 3 things went haywire and needs attention.

Agreed, but the people selling that stuff want you t believe it is.

[tehpwnag3]

Welcome, new guy! This, this, and this.

Just go ahead and toss the Promags now. Save yourself grief in the future. Seriously.

Isn't about time for that crank MistWolf to come in and say "Install a Colt extractor spring".

Boy howdy, I swear that guy thinks extractor springs are the root of all AR malfunctions!

sevignyjoe, in all seriousness, replace your extractor spring with a Colt or Sprinco M4 extractor spring. Short answer- A weak spring lets the extractor lose its grip on the rim of the empty so ejection is weak. The loose empty blocks the new round from feeding correctly and the new round gets smashed into the feed ramps, bending and denting them. Meanwhile, the empty gets shoved out of the ejection port, leaving the hapless shooter frustrated and none the wiser as to what's going on.

I'll guess. DPMS, Andersen, Pro mags or ammunition none of it likes. If it were mine I would shoot up the reloads while practicing clearing malfunctions then go back to Winchester after throwing away the magazines.

AR Stoner is Midway USA's house brand. While I have little doubt that they will take care of you if something goes wrong, I have never felt that the brand was good quality, but it depends on who made the parts for Midway to rebrand them. My blanket statement is to stay away from the brand in the future until they become vetted in the consumer market. However, your new BCG could be fine for a long, long time.

i figured stoner started the whole thing cant be all that bad . the bcg is over all the only thing i have replaced other than the lower it self . on the gun and i got a nickle one for 125. so i will try it