Weight variation vexing!

[mp40man]

I am casting out of a Lyman 475125 mold for a sharps rifle. I am using 20/1 commercial mixed alloy. I am getting weight variations ranging from 418-421gr. I am dipping from the pot and being mindful of consistency in casting technique.

Any thoughts on why I am getting this weight variation or why I can't seem to cast a 525 gr bullet?

Thanks
Greg

[ku4hx]

What's the advertised boolit weight? If you're consistently getting 418-421 grains, I don't think you're ever going to get a 525 grain bullet even with pure lead.

[mp40man]

Thanks for the reply, the advertised weight with that mold is 525, it's the old gov 45-70 bullet.
I got the pre-mixed alloy to account for unknown alloy mixture.

[Jim Flinchbaugh]

there is no way your gonna pick up 100 grains by technique.
Your weight variation is likely because your melted lead isn't hot enough.
Try getting your 20:1 hotter in the pot,you'll find the magic spot

[Kraschenbirn]

Greg...

I think you may have a typo in your original post. Shouldn't that Lyman # be '457125' instead of '475125'?

As for the underweight boolits, are you absolutely certain that your mould isn't a #457124? The 457124 is very similar to the 457125 but with a shorter nose and, cast from 30/1, my old Ideal 457124 drops at around 410 gr.

Bill

[44man]

I think that is right, check numbers.
The 457125 is a 500 gr.

[mp40man]

Yes, typo, on both accounts. The mold is 457125 and is advertised as a 525 gr mold, at least on the Buffalo Arms site. I should have stated that I am getting 518-521 gr bullets.

I should say that my mold does not have any letters after the number either like some of the newer molds.


Sorry guys

[captaint]

40man - I don't think I own ONE mold that drops exactly the number advertised. As long as they're close, no big deal. In this respect, close is close enough. I wouldn't sweat it if it were mine. Mike

[Kraschenbirn]

Hokay...that looks more reasonable. Your '518-521' numbers aren't really that far off the 'advertised weight' which, btw, Lyman lists as 500 gr. (#2 Alloy) in their Cast Bullet Handbooks. I'd say, if you were to lean out your alloy to 30/1, you'll probably pick up enough weight to hit that 525 gr. number. Personally, though, I'd go ahead and shoot those 'light' boolits so long as the variance between boolits is within an acceptable tolerance...and I usually go with +/- 1/2 gr for boolits up to 300 grs and +/- 1.0 gr for anything heavier.

Bill

[runfiverun]

actually you'd have to go to 10-1 to be right close.
just stick with what you are doing.
you will have weight variations based on mold temp and fill out and voids from the casting.
if you are shooting long range, or for score.
just weight sort and use the heavy end, a 2-3 gr variation will not show up on target.
once you get used to seeing what they [your better boolits] look like, you can start targeting that look while casting, this will increase your keeper rate also.

[grouch]

You should have a look at Charley Dell's casting technique in The Modern Scheutzen Rifle. It makes more sense than most I've seen.
Grouch

[mp40man]

Ok, I think that I may be worrying too much about not hitting the weight number. And it sounds like a few grains +\- is not that big of a deal. The bullets look very nice, sharp lube bands and no wrinkles.

I will load some up and take them to the range tomorrow and see what happens.

Thanks

[Alan in Vermont]

That's only 1.67% total spread. That doesn't seem very much worth worrying about with that massive slug.

I'm going to get to play with that boolet design myself. A non-casting buddy just bought one off an ebay auction for barely more than the current Midsouth price of a new one. Now he's gonna have to cough up for a sizer and punch for my Star. He has a BFR and a Marlin to feed but he doesn't shoot either one enough to cause any major dent in my lead stash, even at 14 to the pound.

[mp40man]

I am heading to the range tomorrow with a bunch of them to see how they do. Will oust the results.
Thanks for the responses to my post.
Greg

[mp40man]

Range report- well, they worked out just fine at 200 yards off a bag they were all in the 10/X ring of a 200 yard service rifle target (once I got the sight adjustments made).

Also worked well ringing a hanging gong for some off hand fun!