Gas checks & Lee Sizer

[fireflyfather]

OK, complicated question:

I have the Lee TL-160-312 mold, and it drops about .312 with my alloy. The mosin I shoot it out of slugs at .312. I would prefer about .313 or .314, but I can get 2MOA out of it with this bullet and 7gr of red dot.

I am thinking about trying to drive this bullet at higher velocities (13 gr red dot or thereabouts). How high can I drive this thing before I'm going to need to gas check it? (in grains of Red Dot, not fps, since I don't have a chrono)

If I do need to size it, Lee only makes sizers in .311 and .314 as best as I can tell. Will the .314 sizer seat the gas checks on the .312 bullets? Will the checks stick out? If so, is that a problem? Which brand of gas checks?

I can afford a Lee sizer, but not an expensive lubri-sizer.

 

[SSN Vet]

Lee only makes sizers in .311 and .314

I've run into this exact problem...

there are two solutions...

1. call Lee and order one turned to .312

or

2. lap out the .311 sizer.

.001" of material is not a lot to remove.

Will the .314 sizer seat the gas checks on the .312 bullets?

That's an excellent question. I suspect the answer is yes....

Where's Fred when you need him?

 

[snuffy]

Is this the one? It appears to be a gas check design, so seating a gas check would be simple. As for your as-cast diameter, harder alloy will cast a bit bigger, so will adding a little tin to achieve better fill-out. Otherwise, it's possible to enlarge the mold by spinning a boolit cast in it with a mild abrasive like tooth paste applied to the boolit. Cast a boolit, drill a hole in the base, put a screw in it to be able to spin it in the mold.

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=339539&t=11082005

 

[fireflyfather]

I'm more concerned about the gas checks sticking out, and a .314 sizer being able to seat the gas checks properly on a .312 (in other words, not too loose). I also know there's one brand of gas checks that get crimped on instead of seated with a sizer. I don't want those.

 

[jcwit]

Hornady gas checks are crimped on when the bullet is run through the sizer. Why not shop gun shows, e-bay, your local dealer for a used lube sizer. I've got 2 that I've picked up used, one cose $15 the other $20, and you end up with the real deal.