Bullets for SKS

HShack · September 22, 2011, 01:36 PM

Friend just bought an SKS. I see in Hornaday manual that SKS's have a bore diameter of .311" and that a .310" bullet rather than a .308 is the most accurate. I assume all commercial 7.62x39 ammo has .308 bullets, but does surplus military ammo have .310 bullets? If so, wouldn't it be dangerous in a Mini-30?

**Unclenick** · September 22, 2011, 01:46 PM

No. As an example, the military specifies .30 caliber barrels at .3065" to.3095" groove diameter and bullets at .307" to .309". So they allow for up to 0.0025" interference fit to be normal, and don't even change the load specs for it.

A number of experiments have been done over the years to check pressure rise with bullet diameter, and they tend to show, as long as a bullet isn't so fat it causes the case neck to have trouble chambering, that once it starts swaging into the lands its pressure doesn't go up a large additional amount. Just don't load one too fat to chamber freely. I don't like anything over 0.002" diameter, because accuracy starts to fall off. I get that information from shooting cast bullets, but presume it applies to jacketed ones.

P.S., see MKL's post, here, on P.O. Ackley's experiments firing 8 mm (.323") bullets down a .308 bore.

September 22, 2011, 01:36 PM	#1
HShack Senior Member Join Date: February 5, 2009 Location: Lexington, SC Posts: 106	Bullets for SKS Friend just bought an SKS. I see in Hornaday manual that SKS's have a bore diameter of .311" and that a .310" bullet rather than a .308 is the most accurate. I assume all commercial 7.62x39 ammo has .308 bullets, but does surplus military ammo have .310 bullets? If so, wouldn't it be dangerous in a Mini-30? __________________ Shack

September 22, 2011, 01:46 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	No. As an example, the military specifies .30 caliber barrels at .3065" to.3095" groove diameter and bullets at .307" to .309". So they allow for up to 0.0025" interference fit to be normal, and don't even change the load specs for it. A number of experiments have been done over the years to check pressure rise with bullet diameter, and they tend to show, as long as a bullet isn't so fat it causes the case neck to have trouble chambering, that once it starts swaging into the lands its pressure doesn't go up a large additional amount. Just don't load one too fat to chamber freely. I don't like anything over 0.002" diameter, because accuracy starts to fall off. I get that information from shooting cast bullets, but presume it applies to jacketed ones. P.S., see MKL's post, here, on P.O. Ackley's experiments firing 8 mm (.323") bullets down a .308 bore. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle Last edited by Unclenick; September 22, 2011 at 01:54 PM.