lead shrinkage
- Thread starter Rflshootr
- Start date
L
Larry Elliott
Guest
When you removed the lead casting was it tight? Brownell's sells Cerrosafe, which is a low temp melting alloy specifically for making chamber casts. It's recommended to be measured within an hour after the casting is made to reduce errors due to shrinkage. I'm not sure what the shrinkage of lead would be and I'm too lazy to go downstairs to dig it out of a book, but I doubt that it's 0.003"/0.3".
Have you fired the rifle? It's generally considered that a bore that's tight at the muzzle is better than one that's loose. Shoot it and see what it does.
Have you fired the rifle? It's generally considered that a bore that's tight at the muzzle is better than one that's loose. Shoot it and see what it does.
M
mike in co
Guest
dont bother with pouring lead in a bore for measurements.
consider puring an 8mm cast bullet and lube the bulet and the bore...and then beat it in....., take a rod and tap it out, and measure the formed slug.
do the same at the throat....
fill a case with lead. lube a slug and the throat/bbl. tap an over sized slug in the breech past the throat.
chamber the filled case. from the muzzle end tap the slug back to the case and expand it by more tapping.
remove the case, tap out the slug ...
mike in co
consider puring an 8mm cast bullet and lube the bulet and the bore...and then beat it in....., take a rod and tap it out, and measure the formed slug.
do the same at the throat....
fill a case with lead. lube a slug and the throat/bbl. tap an over sized slug in the breech past the throat.
chamber the filled case. from the muzzle end tap the slug back to the case and expand it by more tapping.
remove the case, tap out the slug ...
mike in co
John Kielly
Shari's fan club
M
mike in co
Guest
sorry john, "sg" ???
soft lead sinkers can often be hammer formed to an appropriate shape for slugging either end.
mike
O
Old Gunner
Guest
I've used OO Buck salvaged from old shot shells and sometimes .375 lead balls I'd first tapped through a 5/16" hole in a steel plate to slug .32 S&W, .308 and .303 bores.
Lead .315 round balls can be found at stores that handle muzzle loader supplies. I bought a box of the RB recently for use in downloaded plinking loads for .32 S&W.
The larger .375 ball when first tapped through a 5/16 hole has a longer easier to read bearing surface than the smaller RB.
An unsized Lyman .303 cast bullet straight from the mold usually measured .314+, I've used those as well.
PS
Very true, and a reason why set back and rechambered barrels often shoot better than a new barrel. I expect than a well used .30/06 barrel when rechambered to one of the .30 magnums with a longer case would probably be more accurate than a new barrel, if the twist is suited to the new chambering that is.
Lead .315 round balls can be found at stores that handle muzzle loader supplies. I bought a box of the RB recently for use in downloaded plinking loads for .32 S&W.
The larger .375 ball when first tapped through a 5/16 hole has a longer easier to read bearing surface than the smaller RB.
An unsized Lyman .303 cast bullet straight from the mold usually measured .314+, I've used those as well.
PS
Very true, and a reason why set back and rechambered barrels often shoot better than a new barrel. I expect than a well used .30/06 barrel when rechambered to one of the .30 magnums with a longer case would probably be more accurate than a new barrel, if the twist is suited to the new chambering that is.
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