5.56 mm Mil Spec Brass and my Savage M12

Cain R · June 20, 2002, 02:09 AM

Just got a Savage Model 12 in .223. I've got several thousand handloads of old 5.56mm handloads that my Armalite M15A2 digests with absolutely no problem.

Trouble is theres no way these loads will chamber in my Savage, commercial brass chamber just fine, even commercial brass fired in the AR and resized with regular Lee dies work okay. But NO WAY for the mil-spec stuff. The only thing I can think of is that the mil-spec has just slightly thicker necks.

Anybody run across this problem before.

Byron Adams · June 20, 2002, 07:05 AM

Were the older reloads neck sized, full length or small base resized. If neck sized, that would be a possibility.

Cheapo · June 20, 2002, 09:40 PM

Uhh, there's also the difference in throat dimensions between military and SAAMI chambers. That's why M193 ball can produce unsafe pressures in bolt guns. Take five rounds and deep-seat them a bit and see what happens.

Are those loads with 55-gr FMJBT military projectiles? If so, switch to 52-gr HPBT match pills for stunning accuracy in a load that'll be safe in both rifles.

Still don't know if there is a similar problem with the M855 ammo and the A2 barrel/chamber... Anyone have info on that?

Cain R · June 23, 2002, 12:41 AM

Hey guys, readjusted my sizing die and all the mil-spec chambers just fine. Funny how the most simple solution is the one you forget about.

C.R.Sam · June 23, 2002, 01:09 AM

TFL Rocks.

June 20, 2002, 02:09 AM	#1
Cain R Senior Member Join Date: August 23, 2001 Location: Peoples Dominion of Kanada Posts: 288	5.56 mm Mil Spec Brass and my Savage M12 Just got a Savage Model 12 in .223. I've got several thousand handloads of old 5.56mm handloads that my Armalite M15A2 digests with absolutely no problem. Trouble is theres no way these loads will chamber in my Savage, commercial brass chamber just fine, even commercial brass fired in the AR and resized with regular Lee dies work okay. But NO WAY for the mil-spec stuff. The only thing I can think of is that the mil-spec has just slightly thicker necks. Anybody run across this problem before.

June 20, 2002, 09:40 PM	#3
Cheapo Senior Member Join Date: November 19, 1998 Posts: 986	Uhh, there's also the difference in throat dimensions between military and SAAMI chambers. That's why M193 ball can produce unsafe pressures in bolt guns. Take five rounds and deep-seat them a bit and see what happens. Are those loads with 55-gr FMJBT military projectiles? If so, switch to 52-gr HPBT match pills for stunning accuracy in a load that'll be safe in both rifles. Still don't know if there is a similar problem with the M855 ammo and the A2 barrel/chamber... Anyone have info on that? __________________ Let us never forget that the only legitimate source of government power is the citizens. If WE cannot exercise a certain power, we cannot grant it to the state.

June 20, 2002, 07:05 AM	#2
Byron Adams Senior Member Join Date: February 25, 2001 Location: Ellijay, GA Posts: 176	Were the older reloads neck sized, full length or small base resized. If neck sized, that would be a possibility.

June 23, 2002, 12:41 AM	#4
Cain R Senior Member Join Date: August 23, 2001 Location: Peoples Dominion of Kanada Posts: 288	Hey guys, readjusted my sizing die and all the mil-spec chambers just fine. Funny how the most simple solution is the one you forget about.

June 23, 2002, 01:09 AM	#5
C.R.Sam Senior Member Join Date: October 30, 1999 Location: Dewey, AZ Posts: 12,864	TFL Rocks.