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Fishoot
03-20-2017, 11:07 AM
I have a rolling block I re-barreled to 32-40. The barrel on the 32-40 is from a new old stock 8mm German made machine gun barrel with .323" bore. I needed a die to lube and seat gas checks for my Lyman 323-470 mold. When I cast boolits (unknown salvaged alloy) with this mold they drop out at from .325 to .326". I copied some early Lyman dies (the ones with 4 thru-holes) and made a die with an inside diameter .324". The die looks good, but when I try to seat gas checks with it the pressure required on the handle makes me fearful the Lyman 45's handle will fail. I really have to lean on it! When I do, the boolit exits with obvious mooshed out grease grooves on one side. So I have a question. Do I need to increase the chamfer on the top of the die from what is (about 30 degrees to a depth of maybe .050") to something steeper and deeper? When I size the same boolits with no gas checks, they come out fine (.324") with no mooshed grease grooves. I plan to shoot black powder or low pressure smokeless loads to something in the neighborhood of 1200 to 1500 fps. I could use the boolit without a gas check but wonder if I want to use the boolit sizer for other 8mm loads what do I need to do to make it work?

mdi
03-20-2017, 12:17 PM
Just a couple thoughts; yep perhaps increasing the "lead" into the die would help in keeping the bullet straight, and secondly, if you have the equipment and where-with-all to make a Lyman type die, why not try a straight through (Lee style) sizing die? I would think a single stage press is stronger than a lubersizer and able to withstand "leaning on the handle". There seems to be a problem other than sizing, as .002" reduction is really very little and shouldn't give any distorted lube grooves...

country gent
03-20-2017, 12:30 PM
Youi can try a more gradual lead into the die it should help and mal allow for better seating of the gas check. Another is to polish the lead and junction between lead and die bright and smooth. a light radious breaking the sharp edge between them helps a lot also.

Mk42gunner
03-20-2017, 02:30 PM
Have you tried annealing the gas checks? It will make a difference.

Robert

Bama
03-20-2017, 05:38 PM
A longer lead in will help. If it is too short, you are pushing lead rather than swaging. I usually have at least a 1/4" lead in and polish with a rubber polishing wheel till it is mirror smooth. It makes a world of difference.

Fishoot
03-20-2017, 07:47 PM
Thanks to all for the ideas! I will try them and let you know. Also, I might try the push through method as used by Lee if I am unable to make this work.

blikseme300
03-20-2017, 08:29 PM
Youi can try a more gradual lead into the die it should help and mal allow for better seating of the gas check. Another is to polish the lead and junction between lead and die bright and smooth. a light radious breaking the sharp edge between them helps a lot also.

This is the best advice after increasing the lead into the die. All my self-made Star dies and tuned Lee ones are treated to this. Bad dies need more force to size and IMHO distortion of the CB does not help accuracy at all.