Military Times article on new 300 AAC BLACKOUT

[Robb Jensen]

I saw an AAC 9" upper today (Jason from AAC) brought one by for us to check out. It's pretty badass.

[mechanicus]

...why not use something that will give an edge vs. the 7.62x39 round. I would like to see other M4 makers like Colt, H7K, LWRC and LMT to bring out an improved 7.62x39 round...

Colt apparently has been working on a trump card for that - check this out: link - A switch-barrel 7.52X51-to-5.56X45...

[shred4Him]

The CM901 looks like it will be able to take any upper, regardless of caliber. That is pretty sweet. What that also allows for is future development of a new round since that magwell can fit anything up to 7.62 NATO.

It still remains to be seen if the larger magwell will create problems for seating smaller mags. This looks like a SCAR 17 killer if it lives up to the early info. Still a long way to go, though.

[carbinero]

The CM901 looks like it will be able to take any upper, regardless of caliber. That is pretty sweet. What that also allows for is future development of a new round since that magwell can fit anything up to 7.62 NATO.

It still remains to be seen if the larger magwell will create problems for seating smaller mags. This looks like a SCAR 17 killer if it lives up to the early info. Still a long way to go, though.

Although it allows for other calibers, I think a system like Colt's would diminish the need.

[shred4Him]

The military has wanted to have a single caliber in the past. Tough to do. A few have claimed that 6.5 Grendel could be that round. Since the military hasn't done any testing that I know of for 6.5 Grendel, who knows. However, developing new rounds for the M4/M16 is restricted by the size of the magwell. With this lower, if they wanted to do a new round and be more creative about it, they could.

Something like that may be 10, 15, 20 years away. However, this lower would allow for a greater range of possibilities.

[rsilvers]

Grendel bolts last - what - 1000 rounds? And they do not feed well from AR mags.

[JWR075]

I have heard the problem with the bolts in the Grendels, I think that people were using a 7.62x39 bolt as opposed to a dedicated Grendel bolt. It has something to do with the depth of the bolt face.

A good solution to the bolt issues would be to use the correct bolt. I would also think that if it were to use a 4 lug design that the lugs could be larger, thus providing more strength.

As for the mags, if a new rifle was dedicated to a Grendel or PPC based round then Grendels mags would work fine, no need to use AR-15 mags.

[JasonM]

What kind of twist do you need to stabilize a 220gr bullet from a subsonic 9inch barrel? 1:8, 1:9??

Ours is 1:8" and works very well.

[SHIVAN]

I saw an AAC 9" upper today (Jason from AAC) brought one by for us to check out. It's pretty badass.

How about some of those 762SD-6 cans for this thing?

[rsilvers]

1:9 had some yaw at 100 yards when tested. I would not do slower than 1:8 if you want subsonic 220 or more grain OTM subsonic bullets.

Also, this is what rifle companies may use to HPT the bolts and barrels: