Gas check question--

[oneokie]

How close to groove diameter does the gc need to be after being seated on the shank of the boolit?

[Blammer]

same dia as the rest of the bullet if you ask me..

[lovedogs]

I'm not sure if there's a certain amount of "spring back" after a checked bullet is sized in a Luber/Sizer but would imagine there has to be some. And I'm not sure if the lead or the copper would spring back the most. I would just guess that the amount of spring back would be pretty small. As it is forced down through the barrel it would all get sized to fit anyway.

[oneokie]

So, would a .375" gc work as intended when applied to a .381" boolit?

[runfiverun]

i think he is looking at maybe using 308 gas checks on like 311 sized bullets
i was going to ask this anyway

[454PB]

Just today I was loading some .310 boolits and measured a few. The gas check was exactly the same as the boolit body.

[Blammer]

I currently use 30 cal GC's on my 311 sized boolits...
work fine.

[Ricochet]

Standard .30 gas checks work fine sizing to .314". At that diameter you can see that they're tapered, sized along a band at the top with the bottom 2/3 or so unsized.

[pearson1662]

What about the gas checks for the 41 Mag? I looked at them on Grafs and I see that they are sized .416. Doesn't that seem a tad large even if you are sizing to .413?

Jay

[felix]

If you have a boolit out of a Lyman mold, then you need Lyman SIZED checks to fit the shanks properly. Gator makes them. ... felix

[Leftoverdj]

There's some elbow room, but how much depends on the batch of checks and how the shank was cut. I use .30 cal GCs sized from .309 to .314. An old batch of Lyman GCs meant for .45 pistol works well enough sized to .460 for my one GC .45-70 mould. On the other hand, my current lot of .44 mag GCs will not stay on at .431 sizing unless I cast of straight lino.