For anyone else interested ??

Here's a vendor that has been mentioned on " 300BLK Forum ", that will make a " Custom 300BLK Barrel # & Custom twist ".
(20" with 1x7 would be my choice).
http://www.saternmachining.com/custom_barrel_prices

Not knowing much .. I would start by looking @ i.e: Wilson's Barrel/contour spec's,& add two more inches to length.
http://www.wilsoncombat.com/press/TR-300RC18.pdf

http://saternmachining.com/barrel_contours

PAPI

quote:

Originally posted by Antelope Sniper:

You mentioned how you thougt it was possible to get more out of the rifle. I've felt the same way.

With QL, 125gr NBT, and a 20" barrel, here are the max velocities projected at various pressures.

50k: 2373
58K: 2475
62K: 2520

So, with a longer barrel, and an operating pressure similar to the SAAMI .223, it appreas possible to achive performance identical to the 30-30.

Do you really think you are going to get better velocities out a .300 Blk than you are out of a 7.62x39, which has a larger case capacity?

I don't think so.

Coole, max pressure in a 762.39 is rated at 51k psi. You will notice the above pressure as above that.

With a 20" barrel and 62K PSI, QL predicts almost 2650 fps with a 125gr BT out of the 7.62x39. Of course that's 11k PSI over recommended max. I've never experimented with high pressure loads in an AK, so, I'm not sure what kind of result it would yield, or if it would even be safe....There is a reason the max is set where it is, and I'm not sure what specific firearm that max is based upon.

Speedy and I have discussed it and he is going to do a tube in a improved 6.5 BR on my 6940 upper. We will get the reamer ordered and be getting it in process pretty soon. Shoud be a real tack driver when it is finished...

In the AR 15series of rifles the 7.62x39 bolt has a more open face then the 5.56 bolt leaving a much thinner ring of metal underneath the locking lugs that it supports. That's why there is a limit to it's pressure in the AR 15. When the 6.5 Grendel first came out it had a broken lug problem because it shares the same cartridge head size as the 7.62x39. This was exaggerated by AA cutting the bolt faces .011 deeper which further weakened the bolt. Most this was negated when a new much stronger steel for the bolt came about. They were then called enhanced bolts.

On the 30 RAR Remington came up with a hybrid AR 15. That is the bolt size was AR 10, but lower receiver is an AR 15 lower, and the upper is a hybrid AR 15...it's bigger then a standard AR 15, but not quite so large as an AR 10. This, in my opinion, was exactly what AA should have done with it's 6.5 Grendel to get the full benefit of that round being loaded to bolt gun pressures.