Newbie- Gas Checks and mold question

[lordgroom]

Actually, I meant to post this on CastBoolits but I can't figure out how to remove the post. Sorry all


Thinking of buying a Lee 2 cavity mold for casting 158 grain SWC in size .358’s. Midway offers one for tumble lube and one with a gas check. I will buy the Lee Lube and Size kit. Here are my questions:

If I have the gas check version, do I need to use a gas check or can I use a gas check with some and no gas check for others (such as not using a gas check for the .38 Special boolits).

If I purchase the tumble lube version can I still run them through the lube and size kit? Do I need to? What is the actual difference between the tumble lube molds and the non tumble lube molds?

Actually, I meant to post this on CastBoolits but I can't figure out how to remove the post.

 

[Russt]

I started with a 2 cavity 125 grain Lee mould and highly suggest the 6 cavity if cash flow allows. I like casting so much I have a dozen or more Lee moulds in various calibers. I sometimes use a TL125TC for the 9mm in 38specials. I have done both , sized and not sized and use the Lee tumble lube. To size or not to size depends a lot on what your mould drops at. My 6 cavity drops at .359 and my 2 cavity drops at .360. I load a dummy round and see if it will chamber. I have a GP 100 and both fit. I have a SP101 and have to size to .357 for it. I've had zero problems with leading but I try to match the PSI of the load with the hardness of the lead. The Lee tester is a big help. I use striaght wheel weights for pistol's and load 700-800fps. I don't have any experiance with gas checks for pistol but I load a 325gr for the 45/70 that is supposed to use a gas check and sometimes I don't. I haven't had leading problems but it's not as accurate without as it is with the gas check. I like a flat base for pistol bullets and never had a reason to use gas checks with light pistol rounds. I've been casting for about 2 years and am still learning. The guys at castboolits know their stuff and are a big help.

 

[hawkeye1]

The Lee molds are great. I have used their regular molds with the Lee lube and worked fine. The tumble lube style work fine. As for the gas check, it is to keep leading down when you drive your bullets faster than normal. This gas check helps keep the lead from sticking to your barrel. So, it is a good thing on your magnum loads. As for regular lower velocity loads you could do without it.
Sizing depends on the dropped size of your bullet and the barrel you are loading for. You generally want your lead bullet about .001" bigger than your barrel or cylender measurement. This aids in accuracy. The bullet will fit the barrel and seal up better and align in the barrel better for accurate loads.
I like the Lee molds. Have not tried the six cavity ones, but would like to someday.

good shooting

 

[Vern Humphrey]

A gas check design has a rebated base, and that works something like a bevel base. In low-pressure loads, it's no problem. As pressure increases, it may allow gas blow-by, and that causes leading and inaccuracy. So stick with low pressures if you don't want to use a gas check with a gas check design.