Hello. I've got a batch of 50 new mags that are giving me trouble with fail to feeds.

I tested 20 of them. 2 had bad welds, leaving 18.

I tested them in 2 guns, a 20" Bushmaster, and a 16" Bushmaster.
20" Bushmaster: 11 of the 18 passed the test - 5 rds manually chambered. 7 failed.
16" Bushmaster: 6 of the 7 mags that failed in the 20" passed. 4 of the 11 mags that passed in the 20" failed in the 16". So I've basically got 7 mags of 18 that work in both guns.

To test, I removed the firing pin for safety, and lubed up the gun. I vigorously pulled the charging handle back and let it snap forward . I DID NOT ride the handle.

I did take a close look at the new mags, and noticed that when looking from the front, that the feedlips are riding on the side of the cartridge. It does it with both sides when the respective round feeds into position. There are major scrape marks on the mags there. See this pic:



I noted that there were major rub marks where the round touches the mag, with significant scraping (no deep scratches, more of a scrape).

In comparison, here are 3 preban mags, none of which touch the round on the side. I Center, 1 Adventureline, and 1 FN:







I also noticed major feedramp marking, and lots of brass shavings in the chamber. I don't know if this is normal and I don't usually see it because the round fired and blew all this stuff away, or if it's abnormal. See here:





I am really starting to wonder if I'm cursed or what? I'm about ready to send them back and only get Centers or new production Okay/NHMTG.  Or is there something possibly wrong with both guns? I'm at my wits end with trying to get new mags that will work properly.

Quoted: If you have an older  "in-spec" Okay mag, and the new ones are not the same, send them back for a refund or correct produced replacements.

It may come to sending them back, but I just wanted to get some feedback and perhaps see if it might be an issue with both guns, before complaing to the vendor. I don't see what could be wrong with both guns (ones that have not had any mag issues before), but I wanted to rule out everything else. I assume that the way I'm testing them is valid (no firing pin, fully loaded, pulling charging handle back hard and letting it snap forward without touching it)?

The 3 preban mags I checked the bad mags against all didn't touch the round anywhere except the very top where the round pressed up against the lip (due to spring pressure). They all have a "crescent" of empty space on the side of the round...whereas the new mags actually touch.

You may want to take a look at this discussion.

Quoted: You may want to take a look at this discussion.

Thanks, but the mags in question are not D&H. I don't want to say who made them until I figure out what is going on (reluctant to start another shitstorm before being SURE it's the mags).

Try replacing your buffer springs. Are all of the mags you have used before that worked old mags? With possibly weak springs? Try taking a spring and follower out of one of these new mags and swapping it with a known working mag, to eliminate the possiblity that it is the mag body with burrs, sharp edges, etc. Also, if you remove the firng pin there is nothing holding the bolt cam pin in place, which could cause binding as it spins.

.

Quoted: Try replacing your buffer springs. Are all of the mags you have used before that worked old mags? With possibly weak springs? Try taking a spring and follower out of one of these new mags and swapping it with a known working mag, to eliminate the possiblity that it is the mag body with burrs, sharp edges, etc. Also, if you remove the firng pin there is nothing holding the bolt cam pin in place, which could cause binding as it spins.

The mags that are known to work well are mags that are pre-ban, but don't have that much use on them. Still, it's a possibility that I'll have to check. I'll swap out a few mag's springs and followers and retry the old bodies with new springs/followers.

I was unaware that the cam pin might move during testing, so I'll have to reinstall it and try at the range (so keep things safe in case of an AD).

Thanks, and I'll report back when I can.

Update:

I just got back from the range. Per a suggestion to test whether it's the mags or perhaps a weak recoil spring, I took 10 preban known good mags apart, put in fresh springs/green followers (the ones that came with the replacement mags). I shot 10 mags in the 20" rifle, and 10 mags in the 16" carbine. Before firing each mag, I hand-cycled the top 5 rds. Out of 20 mags, I had exactly 1 fail to feed. It was the top round on a FN mag, and I wasn't able to repeat it; probably a fluke.

All 600 rds fired, zero fail to feeds, zero problems of any kind. There was also no shavings in the chamber area, and I inspected the first 5 rounds that were hand-cycled. Very little marking on the slugs, unlike with the replacement mags.

I can only conclude it's the mags, not the recoil buffer being weak.

I'm going to see about getting my money back from the vendor, and just move on. I'll order up some Post-ban Center mags, maybe some Okays and see what happens. I see no point in stirring up more awarenss of problems with this mag brand. People have given me enough grief over it. Screw it.

So very frustrating.

Mods, please lock, as the situation has been resolved.

Locked by request.

Locked by request.