Lyman M Die

I love the Lyman M Dies. I use them in several of my pistol calibers, so the answer to your question is, no, I haven't gone back to the standard expander after using the M Dies.

Hope this helps.

Fred

I won't be going back to them anytime soon. I like the M die too much.

Andy

I use the M dies for cast bullets and they are terrific for such IMO. Haven't gone back to standard with lead, and don't plan to.

My Lyman M die works perfectly for cast 45 ACP.

Gone forward on some, not backwards. (Bigger. Custom and/or NOE).

For cast bullets the M die is really a great choice.

I only shoot hard cast bullets and have been using the M step dies for all of my calibers since about 1990. The M step works just fine with jacketed bullets also. The bullet will snap in to the case mouth and sit straight until fully seated. Bullets that go into cases straight come out straight. All of the M step expander buttons were slightly oversized and needed to be turned down a little to give good neck tension. I will never use any other expander die. It was a very good idea.

I use the Lyman "M" die for bottle neck rifle cartridges only and then only with cast boolits.

For straight walled cases I use the expander that comes integral with the die set. I do have to flare the mouth a bit more for my cast boolits, but that's no problem. I tried the "M" die in pistol cases but found its use to just be an extra step with no advantages to a properly adjusted expander die.

I have had problems with cases swaging a cast boolit just a mite and that required I use a slightly larger expander. There is, if memory serves me correctly, a member (or members) on the cast boolits forum that can make you a specific diameter expander plug.

I have "M": dies for my rifle and pistol. I like them, particularly for cast bullets.
Some time in the past, RCBS has gone to an "M" configuration for its expanding /flaring dies.
I called them, and they sent me one of their stepped expanders,(Thank you, RCBS!) which I use now, instead of having to add another step to the reloading process. It works great. The instructions say that the "M" portion of the die will expand the brass ~.002, iirc, and they claim jacketed bullets should "snap" into the case mouth. I haven't been able to "snap" one in yet...maybe I'm not holding my mouth right? For cast bullets, the tiniest bit of flare will assist greatly in getting them into the case without shaving lead.

I definitely recommend them.

If you use lee dies you can get a expander insert form NOE that converts your regular powder through die to a powder through m die. They are around 10 bucks each. He also sales expanders that fit the lee universal flaring die.

I am definitely going to check out NOE inserts - http://noebulletmolds.com/NV/index.php?cPath=91

Thanks!

Love my "M" dies. I only load handguns.

Mr Bullet Feeder sells a REPLACEMENT POWDER FUNNEL
if you have a Dillon Powder Measure that works just like the "M" die.
You just swap out with the Dillon funnel and reset the powder measure.

I just started using one and it works just great.

I suspect Lyman's patent ran out; assuming the M die was in fact patented. Reason I say this is that newer RCBS dies have a stepped expander plug as do Lyman's expanders. RCBS's expanders work great.