I recently purchased a C Sharps 1875 in 45-70 with a 30 inch barrel. This is a 10 pound rifle of recent manufacture.

I'm considering either a Lyman or Hoch mould since they are readily available as opposed to a custom mould. From what I read a 500 grain or so bullet works best. Two Lyman moulds can be bought for the price of one Hoch at Midway. The Hoch are nose pour which is apparently requires more skill and temperature control in casting.

I'm just starting out with both the BPCR and casting. I have an old 20 pound casting pot that someone gave me years ago that does not have temperature control - except if you reverse the power cord plug-in it goes from one power level to another.

Experienced advise would be greatly appreciated! I've read quite a bit of available info and am somewhat acquainted with what's involved.

First, it depends on how far you want to shoot. I use Lyman and RCBS and Lee molds; I shoot the 490 pointed Lyman, and a Snover type, I will check on the weight. But I don't shoot over 300 yards so it doesn't matter much. The 550 grains have higher BCs. Which is why a lot of guys like the .40 cals as a 400 grain forty caliber has the same ballistics as a 550 grain 45 cal with less recoil but that is not what you asked.
If you are hunting at 100 yards, then that is different.

Check out Buffalo Arms.com. They make excellent moulds.

A standard mold that produces a versatile and reasonably accurate bullet is the Lyman 458125 mold. The bullet is a close approximation of the old standard U.S. Government 500-grain .458 bullet designed for the Trapdoor Springfield. It has worked well for me in five different rifles, including a C. Sharps for silhouette and buffalo match shooting. I have since gone to a money bullet design in my match guns only because it allows more powder in a cartridge and shoots a bit flatter at long range. I still use the 458125 in my Trapdoor.

If you plan to hunt with your .45-70, look for a mould with a substantial meplat -- the flat face on the nose. The Lee 405 and 450-grain moulds are pretty bombproof and affordable. Assuming you are going to use black powder as your propellant, you'll want to cast your bullets fairly soft, 1:20 tin-to-lead or softer. You can get the alloy you want from Rotometals and other suppliers -- even Midway.
You'll also want a good lube designed to soften BP fouling. I use SPG with good results.

There is all good advise above.

The first thing to do is to measure the bore and groove diameters in your rifle. Then you can decide on a mold size and also whether or not you want a custom mold. While I am not sure on this I think Buffalo Arms can make a semi custom mold too. I too am thinking about a custom mold for mine.

Then as above what purpose is the bullet. Is it for hunting or is it for targets. And at what range? I am guessing your twist is 1 - 18 but that might not be the case either. That can influence your bullet weight and length sections too.

I have exactly 2 molds for mine. The Lyman 330 Gould bullet and the Redding Saeco #645 which is a 480 grain semi pointed bullet. The Lyman produces a bullet about 458 inch and the Saeco slightly larger.

Basically you want to be able to cast a good bullet, control fouling in your barrel, and load a good round. Then things will start being fun and you can improve the loads and techniques.

Thanks for the replies!

I have ordered a money bullet mould from Buffalo Arms and other bullet casting items. It will be a learning experience for sure. I would like to try match shooting sometime in the future.

If I recall RCBS makes a 300, 400, 500 grain mould, not sure if they are gas checked or not, with the same nose profile and 1 or 2 extra grease grooves for the heavier two weights.
Cal