Too much case expansion w/powder-thru die...

[Harpo]

I'm using a Lee Pro Auto-disk powder measure with riser, and a powder-thru expander die in 38sp. Problem is, when I set the die for full disk travel on the powder measure, I get too much case expansion.

I'm using IMR Trail Boss, 1.09 disk for 4.6grs, and unless the disk moves all the way over, charges are inconsistent.

Any ideas?

Thanks,
Harpo

 

[wally]

Back the die body out (so bottom of the die moves away from the shell holder) until you get the amount of case mouth expansion you desire. Make sure the auto disk riser is screwed in tight top and bottom.

--wally.

 

[ants]

But if you back out the die, the disk no longer travels its full path, does it Harpo? If you back out the disk readjust the chain, and double check everything else like Wally suggests.

What is the problem with your case expansion? Are the cases splitting, or just harder to crimp?

 

[Harpo]

You are correct, Ants - if you back out the die, the disc doesn't move far enough to reliably dump. I'm using a Lee Classic Turret, so there's no chain, just the lift from the case entering the die. Is there a way to use the chain?

It's not an issue with other powders, but Trail Boss requires much larger (in volume) charges.

 

[RustyFN]

You should be able to back the die out until there is no expansion and still get the powder drop to work correctly. Just back it out about 1/4 turn at a time and keep trying.
Rusty

 

[wally]

I have no trouble getting full dumps and not enough bell to seat a bullet, I use volume 1.09 and larger a good bit. I suspect your riser is not tight on one end at least.

Also check that the spring on the auto disk is installed correctly and not put into the wrong spot where it requires too much force.
--wally.

 

[jfh]

Wally (and others) essentially have it--you can tweak the die body height one-eighth or so turn each time, and still get the PTED to function fully.

The problem described can also be caused by improper die adjustment. Make sure the #1 die is set correctly, and that #s 3 & 4 are not too low as well.

A possible related issue is how tight you have the powder hopper screwed down.

Also make sure you have the measure operating lever installed in the correct disk (or bar) slot. In fact, I suspect this could be the problem.

Jim H.