.223 Bullet Weight

darestie · October 24, 2012, 01:35 PM

My Olympic SUM .223 upper has been doing fine with 55gr ammo but I'm curoius if I can get better accuracy out of a lighter bullet. It's a 20" 1 in 10 twist barrel. I picked up some Fioochi extrema with the 40gr Vmax bullet rated at a crazy 3650fps! I'll give it a shot and see how it shoots.

In general though, what is the range of bullet weights that stabilize in a 1 in 10 barrel?

Jimro · October 24, 2012, 03:23 PM

I wouldn't try anything heavier than the 68~69 gr HPBT bullets. But I would try them. You might find good accuracy with the 62gr projectiles.

Jimro

**Art Eatman** · October 24, 2012, 11:26 PM

I inherited some reloads with a round-nosed 70-grain bullet. Sub-MOA in a 1:10 twist barrel. And while not optimum for the weight, 40-grain bullets should group okay with that twist.

moxie · October 25, 2012, 11:11 AM

The 55 and under should be fine with the 1:10. Heavier than 55 really wants a faster twist, which is why we went to the 1:7 with the 62 grainers in the military. But that's just a rule of thumb. As noted above, some guys get excellent resuts with 70 gr. and 1:10. Try different weights and bullets and see what works in your gun.

October 24, 2012, 01:35 PM	#1
darestie Member Join Date: December 2, 2007 Location: Sugar Land, Texas Posts: 57	.223 Bullet Weight My Olympic SUM .223 upper has been doing fine with 55gr ammo but I'm curoius if I can get better accuracy out of a lighter bullet. It's a 20" 1 in 10 twist barrel. I picked up some Fioochi extrema with the 40gr Vmax bullet rated at a crazy 3650fps! I'll give it a shot and see how it shoots. In general though, what is the range of bullet weights that stabilize in a 1 in 10 barrel?

October 24, 2012, 03:23 PM	#2
Jimro Senior Member Join Date: October 18, 2006 Posts: 4,268	I wouldn't try anything heavier than the 68~69 gr HPBT bullets. But I would try them. You might find good accuracy with the 62gr projectiles. Jimro __________________ "Gorsh" said Goofy as secondary explosions racked the beaten zone, "Did I do that?" http://randomthoughtsandguns.blogspot.com/

October 24, 2012, 11:26 PM	#3
Art Eatman Staff Lead Join Date: November 13, 1998 Location: Terlingua, TX, USA Posts: 20,944	I inherited some reloads with a round-nosed 70-grain bullet. Sub-MOA in a 1:10 twist barrel. And while not optimum for the weight, 40-grain bullets should group okay with that twist. __________________ You're from BATFE? Come right in! I use all your fine products!

October 25, 2012, 11:11 AM	#4
moxie Senior Member Join Date: October 17, 2006 Location: TX Posts: 513	The 55 and under should be fine with the 1:10. Heavier than 55 really wants a faster twist, which is why we went to the 1:7 with the 62 grainers in the military. But that's just a rule of thumb. As noted above, some guys get excellent resuts with 70 gr. and 1:10. Try different weights and bullets and see what works in your gun. __________________ If you want to shoot...shoot...don't talk! Tuco USAF Munitions 1969-1992 RVN 1972-1973