Lyman "M" vs. Redding expander stem?

[abcollector]

Most of my dies are Redding and I was wondering if there is a difference between the Redding expander die/stem and the Lyman "M" die? I'm asking because I'd like to open up the area of the case that to cast bullet occupies so the bullet isn't "swaged" down upon seating.

Would the Lyman "M" die be the answer I'm looking for?

TIA

[462]

Could the seating die be the culprit, and not the expander?

[1hole]

"Would the Lyman "M" die be the answer I'm looking for?"

Generally speaking, expanders are expanders. Not quite knowing what you're looking for, or even what your shooting, makes your question somewhat difficult to answer. Redding has copied Lyman's excellant M design for hangun dies but not for rifle so far as I know.

[9.3X62AL]

Could the seating die be the culprit, and not the expander?

Always a possibility, if your cast boolit is .003" (or more) larger than SAAMI jacketed-bullet diameters. Most die sets "assume" the use of jacketed bullets with their dimensioning.

To the O/P's question, concerning expander spuds--it's a "tale of the tape", really. Ya gotta mic those critters, and find out what you're working with. I'm not familiar with the Redding system, just Lyman and RCBS. Where Lyman differs with their M-die is this--it has a "band" (for lack of a better term) above the nominal spud diameter of about .0015"-.002" larger radius, and above that a flaring shoulder. For most applications, I only use the 'band' to open a seat for the boolit base, and don't flare the case mouth at all. In most cases, this provides a slip-fit for the boolit base to slide into and stand upright.

I like the expander spud to be .002"-.0025" smaller than the boolit I'm trying to seat.

[abcollector]

Thanks for the replies!

I notice the "bulge" on straight or taper walled cartridges, .405, .44 mag etc and to me in those cases, the bullet has been swaged down do to the resistance of being pushed into the cartridge.
On the same style of cartridge- straight or taper, I have also noticed that there may be no "bulge" from the bullet once seated but can see the "bands" from the bullet when removed from the seating die. What I mean with this is that there is a polished impression on the outside of the brass the length of the bullet. This to me indicates a seating die that is swaging the bullet down.

Okay, I just unscrewed some of my Redding expander plug stems in rifle calibers and yes, there is a "stepped" up band above the main expander section. This is what I was wondering how the Lyman "M" expander plug worked. It looks like the same idea and that just saved me buying a Lyman "M" die for my straight/taper walled cartridges! So I guess the only other critical difference would be is the actual diameter of the Lyman vs the Redding.

Interesting guys... thanks again.

[GabbyM]

With bottle neck cases die sets don't come with expanders. I have an M die for all my bottle neck cases. Plus most of my hand gun calibers. If you have a bulge in your case there is room for improvement with fit. I'm a huge fan of Lyman M dies. You can make custom size plugs on any half decent lathe. I like a plug .001” to .002” under boolit diameter. With the plug reaching into the case at least as far as my bullet will to counter case tapper variations. This is a big deal in cases like 9mm.

[Calamity Jake]

I'm with Gabby on this one, all my cast rifle ammo get the "M" die treatment with self made expanders of .001-.002 under boolit Ø.

I don't use the "M" die for pistol ammo.

[Gun Nut]

I am having the same bulge problem in my .40 loads