Reloading Lead/Cast bullets

[mvp25560]

What would be a good general rule for converting FMJ bullets to Lead/Cast bullets for reloading.
I have been told to use the starting load of the FMJ and 10% below that, is this a good rule?

[versifier]

If you are talking handguns, the data is usually the same except for magnum loads, the really big boomers, and hand cannons. If you are talking rifles, it all depends upon the case capacity and the load's purpose.

Most critical in either case is proper bullet fit to the bore (.001-.003" larger than groove diameter). Undersized bullets (and overly hard undersized handgun bullets especially) are a waste of time and components. Alloy is critical to the load's purpose for both handguns and rifles - something many commercial casters remain clueless about - and in rifle cartridges the data can change somewhat with the bullet's hardness.

Lyman's Cast Bullet Handbook is the best source of data all around.

If you are into rifle bullets, I can give you a general formula for reducing charges of extruded and flake powder loads in medium capacity cases. NEVER EVER reduce ball powder loads below Jacketed START levels.

[runfiverun]

i'm gonna assume you are talking rifles.
and say flat out no that is not a good rule.
most rifles will not give you good results by doing that and will only give you a loud bang, plus lots of time to think about it while you clean out the bbl.
loading cast in rifles is an exercise in discipline.
you can get the velocity from them,but you have to take the time to do things right.
and some rifles will not cooperate.
others will give you full velocities with little effort and can take the jaxketed loads if the boolit is a good fit to the rifles throat, the Bbl is concentric and smooth and the twist rate of the bbl is slow enough.
but you aren't just gonna take your AR/30-06/308/270 and lower the loads some and substitute cast boolits.
if you are talking a 44/357 mag and the boolit fits the cylinder throats well enough, yeah you can do that, with most powders.

[Jammer Six]

No. Most reloading manuals have listings for lead. They are usually significantly different.

[Paul B]

It's quite difficult to give advice when there are no details. Are you shooting a rifle of handgun? Generally speaking, you can use jacketed bullet data in most handguns and not have a problem as long as bullet fit and hardness ae compatible. Rifles though can be a whole nuther ball game. Some rifles can be loaded to full power loading and darn close to it. The 30-30 and .32 Win. Spl. ae prime examples. More potent cartridges may or may not responde to attempts at reaching ful power status. The 45-70 can not only reach full factory load levels but can surpass them by a very large margin in appropriate firearms.
We need details.
Paul B.

[1Shirt]

Suggest you get a copy of Lee's 2nd Reloading manual. It has some good data if you are looking for rifle that can be used for comparisons to jacketed data.
1Shirt!:coffee:

[mvp25560]

Thanks for all the good information. I do have several Reloading manual like Lee's 2nd Reloading manual 1st edition and Lyman's cast bullets and the 49th edition. I shoot mainly handguns. I also search the internet for information. I sometimes find jacketed load data and have trouble finding cast/lead data information, even when I do find it on the enternet its a wide range of difference. I mainly use Unique and WSF. I thought if I post this thread I may find a good or better way to come up load data. I reload for .45 ACP, .40 S&w and 9mm Luger. Thanks for all the good replies.