What would cause this?

[ADTREM]

I know that PTR's are rough on brass but this? caused 2 failure to feeds in 20rds. Brand new PTR squad carbine. first time firing. To be honest I didn't go thru it before hand. I'm sure that's part of the issue but... Anyone else ever see this? Should I look for anything? I'm new to the roll lock system.

[99HMC4]

What ammo and are the mags HK or cheapos?

[ADTREM]

What ammo and are the mags HK or cheapos?

150gr federal. The mag came with my ptr. It's not HK. I have a few but didn't have a chance to try.

[ADTREM]

The mag says G3 FMP. the ammo is .308 by the way. Not 7.62. If that matters. The round with the bullet was the one that failed to feed. The one in the mag is how it looked when I cleared the malfunction. I will take it down tomorrow and see what I find. First 8 maybe 10 rounds cycled fine but were banged up. I expected the fluting but had no idea it would be that deep.

[U.S. Praetorian]

The case dents are normal. It is caused by the ejected case striking the lip on the rear of the ejection port. You will notice the extractor marks are in line with that dent. There are some slo-mo vids on you tube of a guy shooting a cetme in FA and you can clearly see the case striking in that exact spot. A port buffer will eliminate this. The FTF round is where the previous cartridge rim tried to fit in the trunnion space with the net round. Did it double feed?

[ADTREM]

Thanks for the info. Not sure I could tell if it was a double feed. I don't care if it's all banged up, just wanted to make sure it was running right. Kinda like the beat up brass, I don't reload and the condition of the shells states that this was no AR or M1. Still gonna clean it today. Not my style to not clean first but well, it happened. Any tips on oiling? I've heard they don't like to much oil.

[U.S. Praetorian]

Like I said, get a port buffer from RTG parts, it is worth $30. It will stop the dent and decrease the ejection distance. Clean well and then a light film on moving parts. I use ballistol because it evaporates and leaves a protective film and I use tetra grease on the rails and interfacing carrier. Keep in mind these guns get dirty and will go a long way before they really need to be cleaned. It is a function of direct delayed roller blowback that is also why there are flutes to aid in extraction when all that gas is blown into the chamber.

[GZire]

The unfired cartridge, not normal. I agree that the dents to the side of the case post firing are normal. I see 1 to 2 dents depending on if I'm shooting my 91 or SR9.

I have to think about the case neck still in the magazine.

[michael chen]

were the ftf the first two rounds in the mag? were the 2 ftfs on the cartridges on the same side of the mag?
or was the ftfs where the bolt skipped over the two unfired cartridges?

is the mag too deep in the magwell? or too shallow? looks like the bolt is "gouging" the non-feeding cartridge as it passes over the mag. or perhaps not catching the cartridge rim and thus gouging the unfed round. is the mag angled to one side in the mag well (ie, not perpendicular to the rifle)? looks like a trunion/magazine alignment issue in the receiver to me.

[75bronco]

I think the cartridge in the magazine was dragged forward when the bolt group feed the previous round and when fired it came back and pushed the round back causing the bullet to seat farther into the case and the damage on the case is where the carrier slid over the top of it.