300-221 in an AR help me with mags

[mak91]

I'll try switching out the follower and try the 20 rounder again. The thing that makes me think there is something wrong with the mags is that they have the same issue with .223 loaded in them.

[rsilvers]

Originally Posted by N310toN170

Previously from http://300aacblackout.com/ ;now I don't see it listed on their page anymore:

Because I took it down. It is not so cut and tried that there is one length everyone should use.

[1911man]

Here's what's working for me............

Lancer 20rd, you can load full with short OAL and 15 or so with long loaded ammo

Pmag 20rd with the guts from a 30rd Pmag, works perfect for short loaded and perfect for long loaded or 7.62x40 with the front rib removed. You loose 2-3 rounds capacity but this eliminates the bolt over malfunction completely.

[mavrick]

When you say guts you mean just the follower right? or the spring to?

Dustin

[ezed]

I have had the best luck with PMAGS, both 20 and 30 rd mags. I tried many "proven to work" GI mags, which fed perfectly when used in 223,and none worked well with my Whisper loads. So far, I have loaded, 240 & 220 SMKs as well as the 208 AMAX, all to 2.190/2.220 OAL, and all have functioned perfectly in my unmodified PMAGS.

[dick]

Originally Posted by ezed

I have had the best luck with PMAGS, both 20 and 30 rd mags. I tried many "proven to work" GI mags, which fed perfectly when used in 223,and none worked well with my Whisper loads. So far, I have loaded, 240 & 220 SMKs as well as the 208 AMAX, all to 2.190/2.220 OAL, and all have functioned perfectly in my unmodified PMAGS.

Hi there have you tried adjusting the feed lips on your aluminum GI mags. I have had luck flaring up the ends just a touch with a cresent wrench.

[1911man]

Originally Posted by mavrick

When you say guts you mean just the follower right? or the spring to?

Dustin

Spring and follower

[pud-knocker]

Originally Posted by 1911man

Here's what's working for me............

Lancer 20rd, you can load full with short OAL and 15 or so with long loaded ammo

Pmag 20rd with the guts from a 30rd Pmag, works perfect for short loaded and perfect for long loaded or 7.62x40 with the front rib removed. You loose 2-3 rounds capacity but this eliminates the bolt over malfunction completely.

even with .223 I had some experiences with the bolt over malfunction you described. the followers tilt way more than the 30. I found if I reshaped the top part of the spring to put more pressure on the rear of the follower it helped.

I use the 30 round follower in my 20 round mags with my 300 whisper and 7.62x40 also. no problems with tilt now.

just wish there was a easier way to de-rib the mags.