Carbine class malfunction question

[czgunner]

I took a carbine class this weekend. Fired about 400 rounds.
Rifle used was my Colt 6720 which, before the class had about 200 rounds through it. Generously lubed, and bone stock outside of the Magpul handguard, ambi safety, and SSA trigger.
Mags used were Brownells 30 round, with dark grey Magpul followers. Purchase 10 about 3 or 4 years ago. They were new in package before today.
I had 5-6 malfunctions where the round would try to chamber and stop just a smidge out of battery. On finding a dead trigger I would try to clear the malfunction and once had to mortor to extract the round. The rounds looked a bit "bent". Not sure if that is a good description or not. I'm digging through my crap to see if I can find one of the damaged rounds.
My instructor suspected the mags. I isolated one mag, and set it aside, but had one more malfuction with another mag. I used a total of 4 mags in the class.
Ammo used was Wolf GOLD, vintage 3 years ago. Never had an issue with this batch of Wolf before.
Anybody have any ideas?

Here’s a pic of three I was able to find in my bag.

[opngrnd]

I'd try a different type of mag. Grab a new M3 PMAG and see if there are issues.

[ColtSeavers]

Was the wolf gold used to function test/break in, the same ammo used during the class?
What magazines were used to function test/break in the 6720?
Do you have any other magazines to use instead?
What is/are the production date(s) of the Brownells 30rd magazines w/magpul followers?
Do you have another BCG to use instead?
Have you inspected the gas tube/key alignment?
Did you change the safety and trigger before or after the function test/break in?
Can you give your magazine catch another rotation tighter?

ETA: Are the feed ramps still lined up?

[czgunner]

Was the wolf gold used to function test/break in, the same ammo used during the class? Yes, Wolf Gold is all that has been fired in this rifle.
What magazines were used to function test/break in the 6720? I shot all previous rounds with Brownells 20 round straight mags and Lancer 20 rounders.
Do you have any other magazines to use instead? I did not have anything else available during the class.
What is/are the production date(s) of the Brownells 30rd magazines w/magpul followers? 6/13
Do you have another BCG to use instead? Yes, but 6 failures in 400, probably not the BCG?
Have you inspected the gas tube/key alignment? No interference
Did you change the safety and trigger before or after the function test/break in? Installed as soon as I got the rifle home
Can you give your magazine catch another rotation tighter? I guess I could, but I never had a mag retention concern

Replied to message in bold

[PrarieDog]

I have had issues with the lacquer on the steel case causing extraction issues when the rifle is hot Have not had an issue with the gold.

[Leonidas24]

I had some Brownells 30 rd mags from around the same time period, maybe 2012, that had brown followers and experienced something similar to what you described. The tip of the round would hang up on the edge of the magazine as it was feeding and either get stuck nose down in the mag or dented to the point it wouldn't clear the feedramps. The brown followers and springs were swapped out for Magpul yellow followers and standard springs and it continued to be an issue. In all likelihood the feedlips were out of spec to some extent but I didn't feel like screwing with them and in the trash they went. Okay Ind Surefeeds and Magpul M3s are all I use now.

With that said it's only similar to your problem. 9/10 malfunctions the round wouldn't even leave the mag, let alone attempt to chamber.

[rvanno]

I’ve had problems with wolf gold like this in the past. Try some other ammo.

[ubet]

Magpull mags aren’t expensive, why use anything but them?


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[czgunner]

I have had issues with the lacquer on the steel case causing extraction issues when the rifle is hot Have not had an issue with the gold.

C’mon man. I specifically mentioned Wolf Gold.

[markm]

C’mon man. I specifically mentioned Wolf Gold.

There's an ARFcom invasion here lately.