If you're reloading under time/stress 28 is way easier. I've seen so many mags fall out in competition from not fully seating it's shocking.

31's the only time I ever had a problem.

quote:

Originally posted by 92fstech:
My PSA rifle will work with anything. Our work M400s will close the bolt on a mag filled with 30, but they are a bugger to seat under a closed bolt. Pmags are a little more forgiving than metal ones. Some of our guys inadvertently discovered that you can force 31 rounds into a pmag , and that will cause all kinds of problems.

Oh, yes. This is true.

How old is the magazine?

Old mags should be downloaded, because the spring steel wasn't as good.

New mags? Download if your rifle works better that way.

With the bolt locked back I’ve not had any issue with 30 rounds in a mag. With the bolt forward, it’s hard to seat a usgi aluminum mag loaded to 30. Magpul are fine either way loaded to 30.

But as a matter of practice, I download to 28 in usgi aluminum mags. Magpul get a full 30.

When the Armorer handed me a GAU-5 and the mags, they were 20 rounders, loaded to 18. I carry that practice over to the 30 round mags, loaded to 28.

Carry/use what works in your gun. Trying to make a point using sarcasm effective now: "Look, I use a gladius because my centurion told me to, and his centurion told him to, plus it's never failed me." is not actually an effective argument.

1) If you have confidence in the gun and it will run only 28, then that.

2) If you have confidence in the gun and it will run 30, then run that.

3) If you have confidence in yourself and can only run 28 because you would lose that edge, run 28.

The 2 rounds will only matter until it ACTUALLY matters, either in competition or the real world. I can game out scenarios were the loss of two rounds in the mag caused the death of dozens just as easily as the reverse (I have a great imagination). But this is just speculation and hypotheticals, not real world. In the real world this seems 100% preference, personal experience, and/or psychology, not an actual, factual thing that can be applied across the board.

I cleaned the rifle. Locked the bolt back, inserted a 30rd mag (with thirty rounds in it), slapped the paddle, and it chambered with authority.

Based on that freshly cleaned and oiled performance, I'd never doubt it's ability to chamber the first round off a 30rd mag. However, it is obvious that, when filth builds up a bit, and lube burns off a bit, I can't always count on that performance.

Considering my use of a silencer, I may start downloading to 28 rounds per mag. The maintenance and oil addition regimen with the can is likely not practical to keep up with, if I want to use 30rd mags fully-loaded, and depend on paddle reload performance.

28 because I use pmags and I don't trust the lips long term loaded with the full 30.

My AR has no issues stripping the top round when I've loaded all 30 though, but it's hard to load a full mag on a closed bolt as everyone else has said.

quote:

The maintenance and oil addition regimen with the can is likely not practical to keep up with

That sort of begs the question of what is a good routine suppressed to stay ahead of reliability issues including this one. Maybe a new thread over at suppressed. But I am 100% sure that if you don't clean enough then the bolt isn't going to close on 30 rds. and after enough time maybe less...

GI aluminum mags are really tight on a closed bolt with 30 rounds. I’d definitely download GI aluminum mags to 28.

Magpul gen 3 mags on the other hand, are properly designed and have extra space built into the mag to accommodate a full 30 rounds plus a little extra wiggle room. They easily lock in on a closed bolt because of the extra space. Load these to 30 rounds.

Load to 28. My Twenty round mags loaded to 19

i got 20rd mags. no problems

Absolutely! Mags are made for 30rd, they're loaded to 30, and a proper working rifle should be cycling them without issue. Never any issues using Pmags & Duramags for all my AR rifles in multi cals.