The Gun Counter

I've been over a couple of sites and it seems that it is possible to shoot cast lead bullets in an AR. (Cast Boolits in particular)
Generally speaking you'll be velocity limited. It seems that lead just can't take the spin rate at normal AR velocities.
The consensus seems to be hard as you can get it, 55 gr. Spire points to feed, resize to .225 with a gas check, a slow burning powder (Vargret) and a soft lube (Alox and such)
The guys are shooting from 1800 fps to an upper of 2400 fps with good accuracy and easy clean up. Use is target practice, plinking, and small game.
There may be a need to hoard ammo and reloading supplies until common sense returns to government.....Hey it could happen!

I wonder how much faster they could push the cast bullets if they used an old 1/12 M16a1 barrel.

It' s my experience in using the standard Lyman #2 alloy that the upper limit of bullet speed is determined by twist rate, which translates into rotational velocity (RPM). At anything over 125K, Lyman #2 starts to spin itself apart. Having a bullet come apart as it goes downrange isn't the best for accuracy. I try to limit my cast bullet loads to under 120K RPM.

Bullet RPM is determined by the equation: Bullet RPM = MV X 720/Twist Rate (in inches)

I don't have my data with me, but Lee devoted a full chapter to the idea in his Modern Reloading. The basic idea is that the bullet must be tough enough to withstand the pressure. Low pressure, cast bullet loads, like the standard .45 ACP load require one alloy, while high pressure .rifle loads require another alloy. It's all science, but bullet hardness isn't the end-all. You also want the bullet to be tough enough to take the pressure. A hard bullet might be brittle.

But, yeah, to give a short answer, there is no reason that the AR can't be used with cast bullets.

Welcome to the dark side. May I encourage you to start saving 22LR brass now?

Don't ask why Luke, the Force will reveal it to you.

The use of .22 LR jackets usually requires pure swaged lead, usually with a hydraulic jack set up.

http://www.corbins.com/howto.htm

PawPaw wrote:It' s my experience in using the standard Lyman #2 alloy that the upper limit of bullet speed is determined by twist rate, which translates into rotational velocity (RPM). At anything over 125K, Lyman #2 starts to spin itself apart. Having a bullet come apart as it goes downrange isn't the best for accuracy. I try to limit my cast bullet loads to under 120K RPM.

Bullet RPM is determined by the equation: Bullet RPM = MV X 720/Twist Rate (in inches)

I don't have my data with me, but Lee devoted a full chapter to the idea in his Modern Reloading. The basic idea is that the bullet must be tough enough to withstand the pressure. Low pressure, cast bullet loads, like the standard .45 ACP load require one alloy, while high pressure .rifle loads require another alloy. It's all science, but bullet hardness isn't the end-all. You also want the bullet to be tough enough to take the pressure. A hard bullet might be brittle.

But, yeah, to give a short answer, there is no reason that the AR can't be used with cast bullets.

Using that calculation, I am guessing the 2400fps loads are using a 1/12 barrel already.

Durham68 wrote:Using that calculation, I am guessing the 2400fps loads are using a 1/12 barrel already.

I've never tried to run cast through an AR, but there's no reason why it couldn't be done. The smallest caliber I run cast bullets is .30 cal, but the same rules apply.

blackeagle603 wrote:Welcome to the dark side. May I encourage you to start saving 22LR brass now?

Don't ask why Luke, the Force will reveal it to you.

Most folks new to this game don't realize that RCBS started out with something called the Rock Chuck Bullet Swage (RCBS) which turned soft lead into jacketed bullets.

Bad idea: get some copper tubing a roll of solder. Take Hibatchi to well ventilated area. Pack copper tubing with solder and heat over charcoal. Then uh steal underwear. Cut tube into sections for swaging....steal some more underwear....form bullets.

toad wrote:The use of .22 LR jackets usually requires pure swaged lead, usually with a hydraulic jack set up.

http://www.corbins.com/howto.htm

You can cast lead cores as well.

toad wrote:Bad idea: get some copper tubing a roll of solder. Take Hibatchi to well ventilated area. Pack copper tubing with solder and heat over charcoal. Then uh steal underwear. Cut tube into sections for swaging....steal some more underwear....form bullets.

Some pretty fearsome shotgun slugs are been made from copper pipe caps with lead cores swaged to desired O.D.