M die

[holsterguy]

Anybody use the Lyman m die for 44-40. Having a heck of a time seating bullits straight with Rcbs cowboy dies. Bullits sized at .430.
Putting a LOT of flare and following with Lee powder thru 44 mag expander.
Hoping the m die will work better.
Will it fit in the Rcbs body?
TIA !!!

[EDG]

The M die is a separate die.
If you use only the punch and stem it may fit the RCBS threads.
I use a .44 cal M die plug threaded into my 1970s era RCBS expander die body without any issue. Just check your die threads compared to the Lyman threads.

[Chill Wills]

I think both Lyman and RCBS use 9/16 - 18 thread
Buffalo arms offers just the guts for the expander body at any size you want.
I would think if your bullet is 0.430" one to two thousands under is more then enough.

Try a two diameter expander of 0.428" -- 0.433" for the flair. They work well for cast 44-40 bullets.

[Mal Paso]

I lapped my RCBS Cowboy sizing die to .450" so there's no need to expand the brass again (.431" boolits) and the cowboy expander just bells the mouth.

I have the Carbide Cowboy Set with the brass lock rings and the expander looks like an M die but the shaft is .429" and small enough brass snaps back to .427". There is slight resistance, .429" die in my .428" brass but it's less than the .002" snap back so there is no effect on the cartridge size.

[fralic76]

I also reload 44-40 (rifle & revolver). I have only use Lee dies and have never had a problem with them. Any case that are damaged are self inflicted.

Sent from my SM-G955W using Tapatalk

[holsterguy]

Well, got the m die. Midway had the whole die on sale, so I went that route. What a difference! Have it set to do the "step", plus just a hint of a flair. Works perfect! Bullits are super easy to start straight. No more funny looking neck bulges either!

[sniper]

Holsterguy got that right! I have the Lyman 25 Long "M" die for my rifle, and it works just fine for lead and Jacketed bullets. Now that I have sold my rifle, I don't have use for it any more.
For handguns, RCBS now has an "M"-style expander for their 357 dies, and maybe others. I asked about purchasing one for my set of carbide dies, which was bought years before they started offering the "M" expander. The nice Customer Service rep. mailed me one the same day...sans cost! Works very well! THANK YOU RCBS....again!

[44magLeo]

Lyman has been making M expanders since they bought Ideal. The 310 tool uses them.
These are made with a 5/8 by 24 thread die body. They make adapters to fit 7/8 by 14 presses.
Lyman stopped producing these dies but they can be found on Ebay or from the 310 Shop.
Leo