Wrong Forum. mod please move to cast bullet
I have a Ruger SRH 44mag, 7 1/2" barrel. older model.
I am having a problem with accuracy, I know "its the shooter," But I hant that bad
I have shot 200gr xtp's in my model 29 for years. and I can usually put 6 shots in a 10" target, some times better.
Now I have the disclaimers out of the way.
I slugged the throat on the Ruger and I get .431.
Slugged the bore and the groove measures .429.
I have loaded up cast bullet Keith style 245grs 19grs 2400 .255 lee tumble lube and some 255 copper coated all are SWC. all the same load. They all shot bad all over a 24x24" target board.
These bullets measured .429 and .430.
Instructions for loading and shooting cast bullet state .001" over throat diameter is idea.
all the molds that I see for sale largest is .430
Im going to get a heavier jacketed bullet and see they shoot any different.
Any suggestions are greatly appreciated.
my other post
http://forums.accuratereloadin...2911043/m/8441006152

You can adjust the diameter with different alloys. Linotype usually casts larger than softer alloys.

thanks

There's one old time Lyman mould that can have issues. It's not you in that case....it's the mould. Lyman 429360. I had one that shot a dream. Single cavity. I had another, double cavity, where bullets from one cavity shot well but from the other shot badly.

I run an RCBS 44-240-KT that I got from carpetman some years back as well as an RCBS 44-240-SWC (GC). I size at .430, water dropped wheel weights and my 4 Super Blackhawks gobble them up and print nicely.

Ok, you gave us the answer with your measurements; you Never want your bullets to be smaller than the cylinder throats; Never. what happens if you do, is that the bullet will be gas cut before it gets out of the cylinder, and the base will be distorted.
You want the bullets to be at least equal to the cylinder throat, or .001 over. Then, it won't gas cut, and that is what the forcing cone is for; to make the bullet fit the bore.
Do not make the bullet fit the bore. Make it fit the cylinder.
Also, try a gas check bullet; that will help.
Jacketed bullets; does not matter as much.

If you can't find a mold in the diameter you want, you can lap one slightly larger quite easily.

Procedure:
1) Cast a bullet in the mold.
2) Drive a self-tapping screw into the base (ideally in a lathe, it's best if it's concentric), and cut the head of the screw off.
3) With a hacksaw, cut some slots longitudinally around the bullet.
4) Put some lapping compound on the bullet.
5) Chuck the screw in a drill, and while it is running, carefully close the mould around the bullet.

Stop every once in a while, clean it up and cast a bullet to check. Obviously, you will also need a correctly-sized sazing die.