[ArmChairCommando1954]

In researching 300 AAC Blackout I came across this:

This subsonic ammo is intended for suppressed Short Barrel Rifles (SBR) with pistol length gas systems. 16” barrel rifles will function differently with subsonic and super sonic ammo. If you are unsure how your rifle will perform please check with the gun manufacture.

Traditionally, the .223/5/56 case neck indexes on the internal forward rib of the magazine. When firing Blackout rounds with shorter overall lengths (i.e. supersonic loads) the rib contacts the bullet on its ogive, and this usually isn’t a problem, especially when using modern magazines such as Lancer L5 AWMs or PMags, or GI magazines equipped with non-tilt (i.e. Magpul) followers.

Subsonic ammo for the Blackout is loaded with longer and, usually, thicker projectiles. With longer rounds, especially those with heavy bullets loaded to full mag length, the ribs tend to push the noses together and have the rounds interlace like fingers in the magazine. Depending on the gun/ammo/magazine, this may cause some reliability issues.

D&H INDUSTRIES 300 BLACKOUT MAGAZINES ARE RECOMMENDED TO AVOID RELIABILITY ISSUES

Has anyone had issues with 208g / 220g rounds in a 16" barrel using standard mags or is this just a ploy to sell mags?

 

[txprep]

there is a pretty good forum called 300blktalk. It is a real issue but not everyone has had it.

 

[MadDawg]

Trying to decipher that mess of a statement is like reading out of today's law books....

It used to be that things were written so that a layman could understand what they are trying to say..

I vote ploy. The way I see it- you've got a few options if you get these rounds. It's similar to shooting heavier grain'd rounds in 5.56. No-tilt followers help. The longer rounds might be too tight in the case for certain types of pmags- such as Lancers, PMags, and other polymer magazines. It's because the outside of the mags are the same dimensions- but the internal dimensions of polymer mags are a little less- i.e. tighter clearances.. Suggest that you pick up a few aluminum/metal mags IF you have feeding issues.
But the same problems happen with polymer mags and higher grain'd 5.56.. From what I've been told. ( I don't typically shoot anything other than 55 and 62- although I do have heavier rounds ).
If you don't have a few metal mags- get a few. Check to see if they have no-tilt followers.. Get some 30's, 20's and a few 10's (useful for hunting ). Metal mags tend to be easier to load anyways. The Lancers have metal feed lips anyways- which is why I guess I like them ( and being able to see the rounds ). However in this case- metal mags should give you just a little more clearance (and less feed issues).

Would I buy some metal mags if I didn't own them? Maybe, try them out- you might like them. Try the rounds out. 10 and 20 round mags don't have much of a curve- and even loading them half-way might make them function if they don't function well when fully filled..

 

[MadDawg]

I should note that non-tilt followers aren't the end-all/be-all either. While people will diss a mag that does not have non-tilt followers as being unreliable- well, it's far from the truth. I was using such mags in the early 80's- without issues- for quite some time. We certainly weren't plagued with issues from not having them; it's marketing. get mags that have it if you can. Otherwise- try them as is; buy aftermarket non-tilt followers IF you experience issues; most won't.