Modify a Lyman M-die???

[PBSmith]

I've been reading about the M die until I have headaches. I own one (35 short) and have used it with some success. However, like a few others around here, I'm not happy with the final stage of the die - that sharp-angled belling or flaring step at the top.

The flare is too sharp (about 45 degrees), and it's very touchy to adjust the expander so that cases don't get over-belled. When that happens, sooner rather than later case necks split.

Looks to me like a major improvement would be to reduce the angle on the top part of the beveled expander so that the belling is more gradual. The expander/flaring plug in my Lee .38 special die is about perfect for cast bullets. It has a very slight bevel, maybe only 10-15 degrees, yet is enough to prevent lead shaving.

My question: has anyone here made the modification I describe in the preceding paragraph? I touched a file to the plug - hard as Hades. I don't have a lathe. Any chance the job can be done in a drill press with the appropriate stone?

Or should I simply expand the first two stages in the M-die and then flare with a needle-nose plier? That seems to work okay but might be asking for a cockeyed start of the bullet.

I'm reloading .35 Remington, by the way. Look forward to your input. Thanks.

[HangFireW8]

I had Buckshot make me some to my specs.

I have the same issues and some more. That step often pushes the case neck crooked and ruins the case's concentricity.

Another issue is the dimensions are still for jacketed with lots of neck tension, and lacking a gas check will swage the boolit down, even if it starts OK with the flare. For .308 you can use the .31 M die, but for most calibers there is no convenient plus size available.

[Nueces]

I don't approach that top step with the case neck. Buffalo Arms carries custom made M-dies, ordered by specifying the two diameters. If the top diameter is a couple thousandths larger than sized bullet diameter and the case mouth is gently inside deburrred, seating is smooth and without lead shaving. When the top diameter gets tighter during seating, I know it's time to anneal.

[BK7saum]

Second on what Nueces said. If I'm reaching the 2nd step (3rd diameter) of the expander, it is screwed in too far. However, all my M expanders are made by Buckshot with the smaller diameter the same as my sized boolit diameter or -0.001". The second step is usually +0.004" over the smaller diameter. Standard factory M expander spuds are usually too small on the 2nd diameter to allow a cast boolit to seat.

[Ole Joe Clarke]

A Lee Powder Through Expander might work. About $12.00 at Titan.

[Ken in Iowa]

Second on what Nueces said. If I'm reaching the 2nd step (3rd diameter) of the expander, it is screwed in too far. However, all my M expanders are made by Buckshot with the smaller diameter the same as my sized boolit diameter or -0.001". The second step is usually +0.004" over the smaller diameter. Standard factory M expander spuds are usually too small on the 2nd diameter to allow a cast boolit to seat.

Bingo. Another case where stock loading dies aren't well suited for cast.

NOE now has 'M' type expander plugs in a variety of sizes to use in the LEE universal expander die. I use them in several applications and have resolved issues like yours.

[WALLNUTT]

Buckshot's M die plugs or NOE M type plugs for the LUED both work well.