Gas checks & Sizing dies?

[outbacken]

I'm casting with lee molds and want to add gas checks with Lee sizing dies.
Should I buy the same size die as the bullet or go a little over size?
I plan on loading 6.5x55, 303, 7.62x39, and a generic 170gn 30 cal bullet.

[trying2learn]

Get whatever sizer you want the boolit to be sized to and it will also install the check. I.e. .309 will size to 309 and install a gascheck.

[runfiverun]

outbacken I would suggest you spend a little time reading around here to see how the size/fit makes all the difference between success and wasting time/money.

[outbacken]

Thanks RunFive, But after three hours of reading old posts on various sites, I'm no closer to a diffinitive answer. I just figured I'd cut to the chase and ask the nube question.

[RickinTN]

Generally speaking you want your mold to cast at or just above your desired finished bullet diameter. The sizing die can make the bullet smaller and crimp the gas check. The sizing die can't make the bullet bigger. You can ignore conventional jacketed bullet wisdom on bullet size. For instance in a 30 cal the jacketed bullet called for would be .308". This would be too small for a cast bullet. Generally you would want a cast bullet to be from .001" to .002" larger than bore size, so for the typical 30 cal. rifle you would want a bullet of at least .309" if not .310" or .311", and maybe even .312". I know what some of the bores measure on my 30 cal rifles, but I size bullets to "fill the throat", or in other words the largest bullet that will chamber. This varies from rifle to rifle.
I read and studied this board for over two years before I actually began casting, and I'm sure I have plenty left to learn. That's part of the excitement of learning.
Good Luck to you, and enjoy your casting.
Rick

[GaryN]

Outbacken, welcome to the forum. You need to start at the beginning. The first rule is boolit fit. To get there you need to slug your barrel/barrels. There are stickies here that tell how to do that. Then you will know the size of your barrel and will know what size of sizer to get.

[44man]

Yes, boolit fit. I seat checks in Lee dies by pushing them through base first because if to far from the right fit, I have had them move back when run through nose first.
You might need a punch to fit the nose if not a flat point.

[abunaitoo]

Cast boolet shooting is an art.
Unlike comdoms, for best results, cast boolets need to be sized to the bore.
Lots of shooters at our range refuse to shoot cast. They say it not as accurat as condoms.
More than likely they used the wrong size boolet.
Just because it shoots good in one firearm, dosen't mean it will in another.
First thing is to slugg the bore.
This will tell you what size boolet you want to make.
Welcome to the forum.
Lots of really smart poeple here.