Can Cerrosafe be used to cast a test bullet, strictly for measurement purposes?
Why?
I have a Lyman 452664 mold that is supposed to cast .452” RNFP bullets for my 45 Colt.
After sizing to .452” I have noticed the sizing die smears a tongue of lead (20:1 Rotometals alloy) upward on the side of the bullets ogive along the mold part lines.
This extra displacement of lead only occurs on the part lines, it effectively widens the upper drive band so much so that it interferes with complete chambering of the cartridge. My Wilson and Dillon plunk gauges can’t detect the the misfit ctg’s. The rims are sometimes left standing up off the cylinder just enough to prevent cylinder rotation. Very annoying.
I must test fit every round into a cylinder chamber and those that have their rim standing high, get a light tap to dent the lead smeared up the part lines and seat the rim down.
So the result is my mold cast out of round bullets, the sizing die proves this and causes the upward smearing or displacement of lead along the mold part lines which the widest dimension.
I want to determine if my mold is defective, or if its just my casting technique (mold iron too hot) thats causing of the out of round bullets.
I suspect high heat is expanding the 4 cavity mold iron block length wise along the part line, there by increasing the bullet diameter in this dimension.
I think a virtually cold cast with Cerrosafe my help determine the cause of the out of round bullets. If the Cerrosafe alloy bullet drop and measure with the same diameter perpendicular to the part line as along the part line I’ll know my mold is good. Then just need to work on casting temperature and cadence.