Cast vs jacketed powder charge difference

[okyite]

Hi
Is there a general rule of thumb for using the same weight cast bullet as jacketed bullet in relation to the amount of powder.
Ex. If load data calls for x amount of bullseye for a 200 gr fmj bullet, then how much bullseye would I use for a 200 gr rn cast bullet. I was wondering if jacket bullets generally use more powder or less than the same weight cast bullet.
I hope this makes sense
Thanks

 

[Roadking Larry]

As a general rule, a cast lead bullet will yield a higher velocity with lower pressure than a same weight jacketed bullet.
However when changing a component in a load recipe it is a good idea to back off 10% and work back up.

 

[okyite]

I appreciate that, I have looked in a lot of manuals and no one seems to address this subject. Is the same true if you can't find the same bullet weight in a manual that you want to load. If you have a 200 gr bullet but the manual calls for a 210, would the same rule apply +/- 10%

 

[sabot_round]

Visit this website:

http://data.hodgdon.com/main_menu.asp

 

[technetium-99m]

Check out a Lyman manual, lots of cast bullet loads in there. You should find something to get you started.

 

[ldp4570]

Alot depends on the hardness of the cast, how fast your planning on pushing the projectile, if its being used with a gascheck. Cast bullets can be lots of fun, create less wear and tear on the barrel, and if properly hardend, can be pushed fairly fast.

 

[Shadowrider]

It all depends on the caliber's working velocity. For instance a .45ACP is a low velocity round to begin with, so you can drive a lead bullet the same speed as a jacketed. But a 454 Casull you could drive a lead bullet well past the speed where a lead bullet will shoot well, and do it quite easily.

Realistically you can drive lead bullets to about 1000 FPS before you have problems with leading and accuracy. You can go substantially faster but you have to use hard alloys, gas checks, and other loading methods tuned to your individual gun.

Like others have said with all things being equal lead bullets SHOULD give a little less pressure in a given load and may be a bit faster. But every barrel is an individual so it's best to work up.

 

[Rod Snell]

was wondering if jacket bullets generally use more powder or less than the same weight cast bullet.

Usually, yes, jacketed bullets require more powder than cast bullets for the same velocity.
However, trying to use a general rule that is usually true to guess at what a load might be for a different type bullet can cause trips to the emergency room.
The Lyman cast manual and several of the older manuals have a lot of cast bullet loads.

 

[Roadking Larry]

I've pushed gas checked bullets cast from wheel weight to 2000fps out an 18" barreled Marlin .30-30 with good results, one ragged hole at 50yds open sights.
I've also ran plain base cast .357 magnum loads to 1600fps out of my Marlin 1894C with no leading.
It is all about bore fit, bore condition, lube and powder choices. It can take a bit of experimentation but it can be done.

 

[Shadowrider]

I've pushed gas checked bullets cast from wheel weight to 2000fps out an 18" barreled Marlin .30-30 with good results, one ragged hole at 50yds open sights.
I've also ran plain base cast .357 magnum loads to 1600fps out of my Marlin 1894C with no leading.
It is all about bore fit, bore condition, lube and powder choices. It can take a bit of experimentation but it can be done.

This. ^^^^

A bit of thread jack here. Larry was that rifle's barrel a "Micro-Groove"? Just curious. I've got a .375 Winchester that I want to hot rod a heavy weight bullet out of the "Micro-Grooved" barrel.