rcbs 45-500-fn-gc

so this is one of the first moulds i got and i still really like the profile of it and it is the heaviest boolit i could find that functions thru my guide gun...[marlin]. problem is that as i really like the long bodyed boolit and the wide meplate and i believe it would do very well in the hunting field...as well as for target with the long rifling hugging body...i have yet to get it to not lead any of the 5 45's i have...oops i guess 6 if i count the 458 wm.

ive casted it cool and hot...used two diff lead mix's [being the ww from a tire store here and also from a seller here on cast boolits of lead]. i never have had it not lead even with the gas check. i thought that the gascheck was suppose to deal more efieciantly with such problems. it plops outta the mould at .460ish...being just a tad under that and some i run thru a .459 sizer which just skims the cast mark and some of the driving bands. i also use lyman gc's. another sumptin is that all my bp loads have a felt lubed wad under the boolit. i have yet to do any accuracy tests with it as i havnt gotten it to not lead my barrels.

i cast the lyman 457125 and have never had the leading issue from it nor the 400 lyman 643 mould either. i cast 45 colt slugs with my same lead and lube being 1/3rd bee wax...1/3rd crisco...1/3rd peanut oil. this lube seems to work for just about everything i shoot including the copious amounts of black powder.

any thoughts and has anybody had dealings with this boolit? thanks for your help.:cbpour:

Gas checks do not automatically stop a boolit from leading. It's purpose is to protect the base for deterioration. Your lube should be good for BP but looks a little soft for smokeless. You don't say what your barrels slug at or the velocities you are driving the boolit at. When you size it, it "skims the cast mark and some of the driving bands" which would leave me to believe the boolit is a little undersize. Add some tin to the alloy and it will increase the diameter slightly.

about 75 percent of my trials have been with bp and the remainder have been with rl-7. i keep my velocitys at or around 1200 to 1300 fps. only in my 458 did i try a little hotter with 3031 and then around the 1600 fps mark. all guns that fired this boolit have leaded with all kinds of procedures. my fav rifle is a winchester...[miroku] hiwall hunter model with .0025 inch deep grooves and the ruger #1, the uberti sharps, the browning bpcr are .004 to .0045 inch deep and the marlin is .0035 inch deep. i havnt slugged the 458 yet.

i very much like the profile of this boolit so i may have to try to add the tin and see if i cant get it to stop this infernal leading. thanks for the hint.

My 45-500-FN casts right at .458" and my Marlin likes them a little bigger. I normally use .459" or even .460".

Maybe the bullet's a bit small?

I too have the RCBS 45-500

I have read where it casts a little narrow, but I have yet to cast with it.

my 45/70's are rather on the plump size, at .459+ so I am interested to see is you can get this issue sorted out.

My 45/70s (BLR, Marlin '95 and Ruger #1) all need boolits at least .460 in diameter or they lead badly. I'm driving them at around 1500fps lubed with 45/45/10 and no gas checks.