45-70 M Die Expansion

[paborn]

I just got a Lyman M Die. I've got .460 sized cast boolits. I noticed that the stepped portion of the M Die is very short. When inserted into the case so that the case is expanded by the step, the case will not accept .460 diameter boolits. I've got to flair the case to start the boolit. This makes the M Die useless to me for it's intended purpose. I'm also beginning to wonder if seating boolits in a case so sized and expanded may be making the boolits smaller than .460
Anyone have the same problem? Anyone know where I could get an M expander plug to use with .460 boolits?

Paborn

[462]

paborn,
A pulled boolit will answer your question about it possibly being sized smaller.

Call Lyman about a larger diameter expander plug, giving them the size you need. The plug is threaded onto the die's stem and is interchangeable.

[Calamity Jake]

Ihe expanding section of the M die needs to be as long or longer than the seating depth desired, ie" if .600 of boolit length is seated below the case mouth then the expander section needs to be .600 or greater, then the stepped section above that needs to be .003-.005 larger than boolit dia.
If you are going to shoot different weight boolits in the same caliber then the expander needs to be as long or longer than the heavyest boolit.

Buckshot or a couple of other members here can make you one. You won't get Lyman to make what you need

[coyotebait]

paborn

Buffalo Arms also have in stock custom expander plugs in several sizes per caliber.

coyotebait

[Ben]

You might be better off money wise to buy a Lee 3 die set. Mine expands the case just fine. I have a " snug " friction fit ( I'm using new Remington unfired brass ) , but it isn't overly tight with .459" bullets. I wouldn't think that .001 would make that much difference.

Have you pulled a bullet and miked it to see if the diameter of the bullet prior to seating is the same as the bullet that you've pulled ?
If the 2 numbers are near identical, you aren't going to gain much with the purchase of other dies, expanders, etc.

Thanks,
Ben