Bullet weight

[Nomes]

I cast some bullets in a Lee .357 cal 158gr. SWC about 5yrs. ago some some came out at 160.2 and some at 164.5.
Would there be a big difference in hitting a bullseye at 50 or 100 yrds?

 

[FROGO207]

The question is can you shoot the difference when using same headstamp brass, same primer, and same charge? Many of us can't actually tell the difference at 100 YDS. I probably could not do it realistically. If you can I applaud you.

 

[.308 Norma]

I cast some bullets in a Lee .357 cal 158gr. SWC about 5yrs. ago some some came out at 160.2 and some at 164.5.
Would there be a big difference in hitting a bullseye at 50 or 100 yrds?

Everything else (same gun, powder charge and primer) the same? I'd be surprised if there's any noticeable difference at 50 or 100 yards. Try it anyway though - I'd like to know.

 

[Nomes]

Well I guess I'll load some up mark them as to weight and see.
I'll load them all the same and see what happens in my Big Boy.

 

[243winxb]

some came out at 160.2 and some at 164.5.

Depends
1.Same alloy, cast at the same time? Light bullets may have air pockets in the bullet. Or the mold cavities are very different in size? Accuracy would be poor @ 50 yards.

2. If cast at different times, different alloys, accuracy will be poor also. The 164.5 would have more pure lead, softer.
The 160.2 would have more antimony & be harder. Changes pressure when fired.

The as cast diameter must be large enough to size down.. Do measure diameter after sizing. Out of the same die, harder alloys will be larger in diameter. Soft alloys may produce undersize bullets, out of the same die.

I keep my cast in different lots & watch for point of impact changes between lots.
Hard to tell the difference these days, old age catching up to me.

 

[AJC1]

On cast bullets less than 200 grains with 4 grains of variation, highly suspect. I'm casting two to three tenths at 156 grains at a 154 regulated mold. I bet you see a difference at 15 yards but heck do you.