don't you know, everything on the internet it TRUE!!!!! 16 in barrel 300 AAC Blackout, 125 gr 2,215 ft/s 1,360 ft·lb
123.5 gr 7.62x39 Russian 2,640 ft/s 1,810 ft·lb
Let the numbers speak for themselves.
I do not think of myself as a ballistics expert, but I have been known to play one on the internet.......
I think that when ever a new cartage comes out it is only natural to compare it to one that is well known, like the 30-30. The 7.62x39 has been compared to the 30-30 for a long time now, and in the lighter weight bullets, it can come close.
7.62x39 7.9 g (122 gr) Full metal jacket 730.3 m/s (2,396 ft/s) 2,108 J (1,555 ft·lbf) 10.0 g (154 gr) Spitzer SP 641.3 m/s (2,104 ft/s) 2,056 J (1,516 ft·lbf) 8.0 g (123 gr) Full metal jacket 738.0 m/s (2,421 ft/s) 2,179 J (1,607 ft·lbf) 300 Blackout 125 gr (8 g) OTM 2,215 ft/s (675 m/s) 1,360 ft·lbf (1,840 J) 150 gr.(15.2 Litl' gun 1,932 46,100 CUP 220 gr (14 g) OTM 1,010 ft/s (310 m/s) 498 ft·lbf (675 J)(Made to be fired suppressed)Now, as you can see, in the lighter weights the x39 and the 300 are close, the 30-30 is still faster, but when you get into the heavier bullets, the 30-30 is far and away the better round. The two big advantages the 300 bLK has over the x39 is that for and AR type rifle, they will feed and function far better. The x39 has issues feeding through the strait magwell and the larger bolt face is more prone to breakage. The x39 because of the taper will thrust back harder and lower pressures and the case will not grab the chamber like a 556/300 BLK will. And the other one is the bullets themselves, while both are a 7.62, the x39 is a .311 bullet, while the 300 is a .308, and there are far more choices for reloading out there, the .311 is very limited, mostly made for the 303 British and the 7.62v54R, there not going to work at the x39 speed, so your stuck with the few 123/125 ones. Then there is the ballistic coefficient, .308 bullets are better in flight, thus they will shoot flatter and retain more energy downrange. All there because of BC are all 300 meter rifles, in the 120/130 weight, but the 30-30 can go longer with heavier bullets, it suffers from the flat noise's needed for tube magazines.
Now with all this said, if your going to build up a rifle, and you don't want to do a wildcat or hard to find round, get an AR 10 in 308 and call it good, it will outdo every one of there cartage, and it's far cheaper to shoot.
I hope this helps. JT
Last Edit: Jan 13, 2015 0:49:38 GMT -8 by jeffytune
Good comparison. Ot you could get the new American 30 factory ammuntion when it comes out shortly and put it to rest. It's not exactly hard to load with a set of Herret dies and a case trimmer you ownanyway.
If I wanted a hammer for bg bullets I would go with a Bushmaster or the SOCOM. Bushy stuff is all over the place and not that expensive. Certinaly it will out run all of them in the 200+ bullet category. If I wanted fast then the 264 LBC would do fine or staying mid-weight the 6.8.
So many choices. We make O'Connor and Keith look like beginners.
The best firearm for self defense? Any loaded one will do.