More on Expander dies

[1bluehorse]

Just read through the thread on expander dies and Gears good reply on the RCBS die. My questions are, do you all (those who use them) find the "M" die or the RCBS expander die, to make a real difference in accuracy for straight wall pistol rounds? I've not used the Lyman "M" die but do have and use RCBS dies on my progressive presses (which I use little) but use Lee dies (including the PT expander die) on my Turret press (which I use the most) Gear's answer (the RCBS expander die) seemed to me to be mostly aimed at bottle neck cases so are the results the same for straight walled stuff? I guess the real question I'm asking is, are either one worth the difference (over the Lee or others expander die) just for accuracy's sake?

[UNIQUEDOT]

I use the (M) die for loading pistol calibers on my loadmaster because it greatly speeds the process for me as it allows me to simply set a bullet without holding it as the usage of the (M) die allows the bullet to remain straight for seating. As far as Improving accuracy there are plenty of articles written on it from WAAAAY back explaining how it improves accuracy, but i don't think i can shoot a handgun well enough to tell. After the thread you mention i checked out the rcbs expander and noticed the design was prehistoric and decided it wasn't for me, but since i have not actually used it i have no idea if it's performance is modern or not. I'm stickin' to my (M) dies.

[UNIQUEDOT]

I read an article once that said a Lee universal flaring die would produce more accurate ammo with J bullets cause the flaring stem could be adjusted to float and since the (M) plug doesn't if your press was not perfectly aligned or the case entered crooked for whatever reason the floating flair stem wouldn't knock the neck out of alignment. Since one would have obviously used the same press for sizing and seating though i don't know what difference it would make. Another thing about the (M) die is that Lyman will make custom plugs to match the boolits you're using ( i guess they still offer this service) and cases last longer when using them for bottlenecks if you've remembered to remove the expander from the sizer.

[Old Caster]

It depends on the caliber mostly and the smaller the diameter of the load you are using the more important they are. For 45 and 38 I use just the expander that Dillon offers for their powder system but for 9mm and 32 I had to custom make them and then it depended on which gun I was going to shoot them out of. -- Bill --

[geargnasher]

I read an article once that said a Lee universal flaring die would produce more accurate ammo with J bullets cause the flaring stem could be adjusted to float and since the (M) plug doesn't if your press was not perfectly aligned or the case entered crooked for whatever reason the floating flair stem wouldn't knock the neck out of alignment. Since one would have obviously used the same press for sizing and seating though i don't know what difference it would make. Another thing about the (M) die is that Lyman will make custom plugs to match the boolits you're using ( i guess they still offer this service) and cases last longer when using them for bottlenecks if you've remembered to remove the expander from the sizer.

Whoever said that about the Lee flaring die needs to go back to flipping burgers for a living instead of writing gun articles. Take a fully sized case, flare it with the Lee die, and cram a boolit in there. Then take a straightedge and a feeler gauge and tell me how even the bulge is in the case. At least use an M die, even then if the boolit is having to plow the case open more than about two thousandths all sorts of off-kilter stuff can happen to the boolit base and the brass. All you need is a correctly expanded case and a beveled flare at the top, the boolit will find center because that's the path of least resistance. You don't need a floating expander or floating seater plug, all that is ad hyperbole to make the super-sloppy fit of Lee plugs seem ok. There is plenty of slack in most shellholders to let the case center itself just fine if the ram and die are slightly out of alignment. If a seater or expander plug floats around to accomplish alignment if the die body is off-center with the case, since the plug is at the top it just goes in crooked. The case head keeps the case plumb with the die unless the rim is bent, head isn't square, or there's an issue with the shellplate being level.

I've shot plenty of "better" targets with RCBS expander dies than when using Lee dies with factory expanders. I've also shot many good groups with custom-made floating expanders in Lee powder-thru dies sitting in my Pro-1000s. I don't use M dies for pistol, so honestly I can't say if they're better or not than the RCBS. I do know that it's all about the shape of the brass before the boolit is seated, though, and however you get there doesn't really matter.

Gear

[Char-Gar]

I don't think there is much if any difference between a Lyman M-die and an RCBS or any other make of plug type expander for straight walled handgun rounds. Many folks prefer the Lyman die because it doesn't flair the end of the case. But, in all truth, I don't think it matters one bit.

Now the diamter of the expanding plug does matter depending on how hard or soft the alloy is. If the alloy is soft enough to be damaged by shoving in in a too tight case, then you need a larger expander plug. If you are using a hard alloy, then it probably doesn't make much of a difference. I have a friend (Jim Taylor) who gets super accuracy with such rounds and doesn't expand the brass at all. His loaded round look like the snake that swallowed the pig, but it works for him.

The answer to your question, like most of them on this board, requires an answer of "it depends".

[UNIQUEDOT]

Whoever said that about the Lee flaring die needs to go back to flipping burgers for a living instead of writing gun articles.

I don't remember who wrote the article, but i do remember reading it and thinking what difference the floating flare stem would make with an out of alignment arrangement especially since if a flare only die is used you would have to use the normal expander in the sizing die and then there's the bullet seating to be dealt with. Richard Lee himself said a bullet was the poorest of expanders.