Major Power Factor Rifles in USPSA

[rsilvers]

www.300aacblackout.com

Today I shot 175 Sierra MK at 1950 fps from a 20 inch AR (340PF). It should be able to do a 330PF from a 16 inch. AA1680 or H110 powder, 2.26 OAL.

Compared to 300 Fireball, 30-221, or 300 Whisper®, the freebore is longer, which tends to allow it to be loaded to a higher velocity before reaching max pressure. So it is like comparing 5.56mm to 223, or 6.8 SPC-II to 6.8 SAAMI.

Remington is loading factory ammo and about a dozen companies are making products soon or have already.

30 round magazine capacity and uses standard bolt face. Feeding is reliable and bolts don't break prematurely.

http://www.silencertalk.com/forum/viewforum.php?f=128

http://www.m4carbine.net/showthread.php?t=63569

http://www.ar15.com/forums/topic.html?b=3&f=121&t=512119&page=1

[RAZZ]

About a year and a half ago I had some money burning a hole in my pocket, so I decided to invest in a 6.8 for 3-gun. I finally got around to working up a load the other day, and was able to make major with a max load of XTerm, and cheap 130 gr bulk SP bullets out of a 20" barrel.

Now that I have it, all I can see is how useless it is. Oh well, It's fun to shoot.

[fastshooter03]

FWIW Another round to consider is the 7.62x40mm.

It is basically a long version of the 30-221 designed for use with 125ish gn bullets.

Advertised velocity w/125 is 2475fps--16" and 2600fps--20".

I'm guessing with a good match barrel with special rifling it wouldn't be a prob with an 18".

All you need is to modify the rib on ar mags.

I have a reamer and die set for this round but haven't received a barrel blank yet.

I was considering this round for hunting mostly.

If you think running a special round to get a few more points with help you finish higher in the end and you can afford the extra cost, then go for it.

I for one need a lot more help than that!

Especially since there's a shotgun and pistol involved too.

Nick

[ken hebert]

www.300aacblackout.com

Today I shot 175 Sierra MK at 1950 fps from a 20 inch AR (340PF). It should be able to do a 330PF from a 16 inch. AA1680 or H110 powder, 2.26 OAL.

I plugged that info into the good ole ballistic calculator and while yes, it does make major, it has twice the drop of .223 at the same ranges. I'll jokingly call it a .308 mortar.

175g SMK at 1950fps, assuming a zero at 200yds:

100yds +4.60"

200yds 0.00"

300yds -17.2"

400yds -49.1"

500yds -98.4"

I also realize this is testing and development right now, for these purposes, but I for one ain't gonna fork up the $ to shoot 175g SMK's in a 3gun match! But I am interested in seeing where this might lead, especially with something in the 125g-ish range bullet with some oomph behind it to work the comp.

[Bryan 45]

I understand the idea behind this cartridge- and like it. But like Ken said, for our game it will only be interesting if the 110g or 125g are fast enough to drop less than about 10" at 300 w/ a 200 zero.

I can't imagine this cartridge being able to get the 110g up to 2910 fps. But the 125g at 2560 may be possible out of a 20" tube.

[Nicolas.]

Does anyone use Gremlin today ?

[ken hebert]

I think one guy does, in a very specific match.