Powders for Cast Bullets

[rbernie]

Why are the loads shown for cast bullets always using super-fast powders (relative to the jacketed bullets fo the same weight for the same caliber)?

I'm thinking of running some gas-check 210+gr cast bullets in my Enfields (303 British) but the available load data doesn't really look all that promising...

(edited to include intention to run gas check cast designs)

 

[Fatelvis]

Ive experimented alot with the 303 Brit and cast bullets, and by far, the best load I have found is wheel weights, cast in Lyman`s #314299 bullet, sized to .314", Hornady gas check, over 16- 18.5 grns. of Herc. 2400. Use a standard primer. It is mild, leads very little,( if at all), and is accurate as all get out!! Just load them in your rifle using stripper clips or one at a time. This powder doesn`t seem to be position sensitive, so dont bother pointing the rifle up, down, or any of that to settle the charge.

 

[steveno]

I think Unique would be another good powder to use

 

[rbernie]

I think Unique would be another good powder to use

But this is exactly my question - why would/should I use such a fast powder for cast bullets in a rifle when I would use, say, H4350 fot jacketed bullets?

 

[PinnedAndRecessed]

I'm no expert (although I play one on television) but if I were to be awakened in the middle of the night and a guy was holding a gun to my head and asked, "Why use fast powders with lead bullets?!", I think I'd offer the following:

Lead has a lower coefficient of friction and it's going to start moving right away. With a lower coefficient of friction the bullet will be exiting the barrel before the powder is finished burning. That means the velocity is reduced.

Therefore, to get the velocity up to spec, which means the powder must be ignited before said bullet exits said barrel, one would have to use a faster burning powder.

Then again, I might have been watching "Cliff" on "Cheers" too much.

 

[rbernie]

This largely mirrors my own thinking and expectations. But what's bothering me is that it's not like the recipes call for moving from IMR4064 to, say, H4895 - they'll move all the way to H110 or 2400 pistol powders.

That's just a HUGE shift in burn rate, and I wonder if they're deliberately trying to keep the speeds down to keep non-gas-checked bullets from leading too badly.

 

[Gewehr98]

You may have just answered your own question.

I wonder if they're deliberately trying to keep the speeds down to keep non-gas-checked bullets from leading too badly.

Yup. Look at the difference in muzzle velocities. When you add a gas check to that cast bullet, then you can start using things like IMR 3031 or IMR 4198 without leaving solder streaks enroute to the muzzle.

 

[rbernie]

When you add a gas check to that cast bullet, then you can start using things like IMR 3031 or IMR 4198 without leaving solder streaks enroute to the muzzle.

What's been throwing me is that all of the current load manuals that show these light loads for cast bullets are actually using a gas-check design bullet. So if they're using gas checks - why in the h*(& are they still keeping the velocity so low? No doubt to just confuse me...

Looking at this from a speed (and not from a pressure) perspective - is there a upper speed limit for hardcast gas-check bullets? Is it generally OK (understanding that this is ultimately gonna be barrel-and-action specific) to step up to, say, 2200fps-2400fps?

 

[Jim Watson]

Getting good accuracy out of a cast bullet, even gas checked, is harder at higher velocity. If everything is just right, lead, lube, barrel, and load, it is possible to do OK with a cast bullet at 2000+ fps. But slower is easier. I am not trying to prove something by shooting game or matches with cast bullets, I want cheap, comfortable practice.

If you reduce the load of, say, 4064 to get a .30-06 cast bullet down into the 1500 fps range, pressure is too low for a smooth burn of rifle powder and velocity is erratic. There have been instances of kaBooms with greatly reduced loads of slow-burning powder, too. You need a much faster powder for cast bullets unless you are trying for near jacketed bullet performance.

Some people have seen good results with a case full of very slow burning powder under a cast bullet, but I consider that advanced handloading.

I have tried this and that, but my M70 sporter '06 shoots lead well with a little 700X or some more 2400. No need to push it.

 

[rbernie]

I am not trying to prove something by shooting game or matches with cast bullets,

Well, if I want a 220gr bullet for my 303R, I'm pretty much stuck with hardcast as my only option. For this weight of bullet, the 303R *should* be capable of at least 2000fps without stressing the action/brass too much.

Some people have seen good results with a case full of very slow burning powder under a cast bullet, but I consider that advanced handloading.

I guess I'm just gonna have to load some up and see what happens.