Magpul 5.56 M2 vs M3, any 300 BLK experience?

[Ronaldo Crespin]

I just received an order for some Magpul M2 5.56 mags (only way I could get FDE). I purchased these to be dedicated 300 BLK mags for my 16" build. After transferring some 300 BLK from an M3 to an M2 I noticed that the M2 does not hold the rounds in place as well as the M3. Does anybody know if this will be a problem?

I can see that there is a difference in the design of the interior with the extra protrusions added in the M3.

 

[TheGman]

I have a few Gen 3 but have never used any in for answers

 

[Ronaldo Crespin]

And, of course, "New for Spring of 2017" Magpul is going to sell dedicated 300 BLK mags. Good deal but for my needs I will have to get them cerakoted, unless they make some in my color. And, since it is already Spring in the great state of Georgia, I guess they will be on sale soon.

 

[Jambo]

The Gen 3's rattle in my AR, and the bump on the rear of the mag makes it a little harder to get out of my mag pouches. Other than that, they both run 5.56 fine.

 

[BangBang]

I've got an AR lower that gen2's will NOT go into the mag well on AT ALL. I don't mean they're just a little tight either. I mean you have to FORCE them in, and then it's HELL to pull them back out.

Gen3's work perfectly in this same lower and even drop free empty, so there are definitely some size differences between gen2 and gen3.

It's an 80% lower that I completed myself, so no idea who the manufacturer is.