300 BLK PMAG Gen M3 Fun! (Video)

[Quiet Riot]

I wouldn't be so bold as to call this a "test video," but I did take my new gen PMAGs to the range to see if I could induce a failure. The only problem I've had with any standard 5.56 mag related to the 300 BLK has been when a loaded mag has some sort of impact, making a mess of the rounds in the stack. This happens mainly when I load 220gr subsonics, and it makes sense. The bullets are 4x the weight of XM193 bullets, making the mag spring work extra hard to keep everything in the box organized and happy.

The Gen M3 has a few big changes to the follower and spring base plate. There are also subtle differences to the internal ribs. It my brief testing, I had a hard time getting the rounds to bind up in the new PMAG like I occasionally have happen in the 2nd gen PMAGs. In any case, other than spitting a few rounds out of the top, these mags performed flawlessly for me with both 220gr subs and 115gr supers.

Two other observations:
1. I had no problems seating these mags with my Mega Arms Ambi Billet lower. This was mentioned by Stickman before, but I personally confirmed that a regular guy won't have issues, either.
2. This is one of the coolest videos of suppressed 300 BLK that I've done so far. Subs and supers sound phenomenal in the rapid fire mag dumps.

http://www.youtube.com/watch?v=_ST-wJ1Ekj8

[mic2377]

Outstanding test. Thank you for this info. I have been running only GI mags due to reported PMAG issues. I will definitely give it a shot now.

Also, do you reload? A friend of mine has a 9.5" Core15 barrel on his 300 BLK, and it is alot quieter with some other powders than the standard A1680 that is run in the factory sub loads. We ran some loads over the weekend w/H4198 and it was awesomely quiet. Good accuracy and cleaner to boot, too.

Thanks again!

[darr3239]

With my Gen 2 mags, I've gotten the same result when I forcibly jam the them into the receiver. The top round will jump out into the receiver. If you let the bolt go, then you have a double feed.

Yep, I shouldn't jam them in like that, but it's never happened to me with the 5.56. It's something I'm keeping in mind now.