Fail To Feed/Double Feed? Magazine Problem or Something Else?

[joeg26er]

OK thought it was my lightweight carrier (I know..)

When firing, it will fire two rounds then mis feed. The bolt will jam into the cartridge midsection denting it pretty badly.

but then dropped in a Stag NiB full weight FA standard BCG and it still did it

and getting this when cycling the charging handle to strip rounds - see pics

could it just be some bad magazines/ weak mag springs?

I was using some very high quality 20 round OKay Ind. black teflon coated mags and did not even consider something being wrong with those.
they don't have the anti-tilt followers though...

I stripped rounds from some 30s from C Products that had no issues. Will have to try those in live fire.

Any help is appreciated. Thanks

IMG-3518.jpgIMG-3519.jpgIMG-3520.jpg

[MegademiC]

When you changed bcg, you mean including a different bolt?

What exactly do you see? A fresh round that was overridden by the bolt, where is the empty?

Do you have 1 or 2 fresh rounds stipped from the mag?

You are getting this malfunction even when hand cycling the bolt?

Do other mags work flawlessly?

Is this a new build, has the upper and/or lower been reliable in the past? Factory gun?

[joeg26er]

When you changed bcg, you mean including a different bolt?

What exactly do you see? A fresh round that was overridden by the bolt, where is the empty?

Do you have 1 or 2 fresh rounds stipped from the mag?

You are getting this malfunction even when hand cycling the bolt?

Do other mags work flawlessly?

Is this a new build, has the upper and/or lower been reliable in the past? Factory gun?

The upper is a 2A billet, 2A rail, Spikes 11.5, 2a Ti gas block, Radian Raptor charging handle so should not be an issue with the parts. Everything is torqued to spec.
lower is San Tan billet ambi, Stag LPC + POF trigger. Standard carbine spring and buffer. Tailhook mod 2.

Each time using a totally different Bolt and Carrier group.

I got hung up on using just the OKAY 20 rounders so will have to try to use the anti-tilt CProducts 30 rounders next range session.

This is a new build and now that I think more clearly about it, I am a bit more certain it's the 20rounders that have been giving me issues that I was ascribing to the BCG.

The casing is ejected, the next round is jammed tip up and with the bolt denting it about midway.

[P2000]

If the bolt is trying to strip two rounds from the magazine at the same time, it is because the magazine is presenting two rounds to the bolt. In this case it would be the magazine's fault

However, not sure if you are saying the rifle is trying to feed two live rounds at the same time. Is this what you are saying?

If it is just one live round failing to feed, getting that dent in the middle of the case, this usually is from the bolt missing the case and the bolt carrier itself trying to strip the case from the mag. This can be from short stroking, or the action outrunning the magazine.

[dmd08]

Does it lock back after one round is fired from the mag?

Why a standard carbine buffer?

If it does lock back after the last round I'd put an H2 buffer in it and see if it changes anything.

[joeg26er]

In the pics above the bolt edge is caught on the back of the round and the round has its tip jammed against the feed ramp

[LMT/556]

Twenty round okay mags don't need an aftermarket anti-tilt follower. "The bolt will jam into the cartridge midsection denting it pretty badly." If the round presents at a high angle during this misfeed, in my experience this is caused by the round being stripped by the carrier and not the bolt. In my case it was caused by a loose gas key and once torqued to the proper torque (55in/lbs) it was GTG. The round partially stripped straight into the feed ramp might indicate a feed lip issue, I'd compare how the rounds present to a known good mag.
One time I bought 4 mags from and individual off GB that he originally bought as "kits", and assembled the mag springs in upside down. This caused an intermittent issue like you describe and that is an easy check.

[LMT/556]

IMG_20160321_162342_523.jpg
Good left, bad right...

[joeg26er]

IMG_20160321_162342_523.jpg
Good left, bad right...

Thanks - AFAIK the OKay Industries 20 rounders can't have the spring inserted upside down as one end has a special turned in section of spring that attaches to the follower

[LMT/556]

That didn't stop someone doing it in my case.