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tommag
08-20-2013, 03:38 PM
I cast a few hundred .530 rbs this morning. Box says 224 grs. Using lead from sheeting and old sewer joints, after culling wrinkles and voids at the sprue, I put them on a scale. Mostly between 219-221 grs with a few as low as 218.5 and the high 222.5 grs.
Does this sound close to pure pb, or maybe there was a fair bit of tin in the mix?
I figured hotter would be heavier, but the frosted ones were the lightest.
Maven
08-20-2013, 07:26 PM
Yes, it is close to pure Pb. However, you'll need to use a mic. to determine the actual diameter, then enter that information here: http://www.beartoothbullets.com/rescources/calculators/php/roundball.htm?v1=.495&v2=2876.1
fouronesix
08-20-2013, 07:58 PM
219-221 grains from a mold that "says" 224 is really well within the expected range. Your lead from those sources is likely pretty soft- so no worries about that. Flux with a little saw dust, stir and skim often. Get the pot and mold up to a temp just beyond shiny and wrinkly but short of heavy frost, maintain a casting pace and keep going! A zillion other things in accurately shooting patched roundballs will overshadow the weight variations your seeing in those cast roundballs.
mainiac
08-20-2013, 08:17 PM
i think my .530,s weigh 230 grs,with pure..
mooman76
08-20-2013, 08:42 PM
There is also the chance that you could have a tiny air bubble.
tommag
08-20-2013, 10:33 PM
I didn't use a mike, just the calipers. They were right at 528, and that calculator said 220, so I guess my pb is close to pure. Anything under 219 went back into the pot.
Also, got some ballistol and made moose milk, per Waksupis advice. I can't help but think it belongs in the fridge, it really looks like milk!
Beerd
08-22-2013, 03:24 PM
to calculate the weight in grains of a pure lead round ball you can:

cube the diameter and multiply by 1500

or

multiply the diameter by itself two times and then multiply that by 1500

so

.528 x .528 x .528 x 1500 = 220.8 grains


..



(playing with this formula some, a cube of lead one foot on each side weighs 700 pounds!)
Boerrancher
08-23-2013, 12:55 AM
(playing with this formula some, a cube of lead one foot on each side weighs 700 pounds!)

Just think, gold weighs almost half again as much as lead when it is pure so imagine owning a cubic foot of gold. Wouldn't that be great... Until you had to move it.

Best wishes

Joe