gas checks

[twally]

Will going to a gas checked boolit stop my leading in the barrel problem? or is there more to it than just adding a gas check?
I'm loading .40 s&w pistol rounds.

[runfiverun]

or is there more to it than just adding a gas check?


yeah there's a lot more to it.

i'm just guessing.
a lee 175 t/l mold at .401.
alox.
or a fcd die is involved here somehow.
and most over 900 fps.

[twally]

I am using alox but a regular lube groove , but also using commercial cast and still getting lead, only pushing about 850fps. 3.3 gr clays

[geargnasher]

Wow, yeah, there's a LOT more to it.

Twally, do yourself a favor and do a forum search using my handle and the term ".40", "FCD", or "undersized". Me and several others have discussed all the problems associated with the .40 and cast many, times, and explained the solutions to the problem you're having, which I think are probably fourfold (undersized expander, undersized boolits, poor lube, and the FCD).

Gear

[twally]

geargnasher, I'm not having any luck searching the topics you suggested.
I do not use a fcd but I do use a dillon taper crimp die, do you think my crimp is too tight causing my bullet to be undersized?

[runfiverun]

it can.
if the boolits start out too small to begin with it won't matter.
the expander can let the case squeeze a boolit down too.
and the taper crimp can deform a loaded round.
most 40's have a bbl size around 401.

[waksupi]

The commercial bullets are most likely a large part of the problem. Generally undersize.

[geargnasher]

I went to the advanced search screen, typed in ".40" in the keyword field, my handle in the username field, highlighted "cast boolits" as a forum to search in, and hit submit. Just about every thread on the first page contained pertinent information. Here's a good one, read my overview on post #3, relating my experiences with the .40, failures and what I did to fix it.

http://castboolits.gunloads.com/showthread.php?t=134820&highlight=.40

Gear

[popper]

GC won't help a bit Specify bullet, measured size, lube, load and BHN if you know it.