9mm expander die

[TXCOONDOG]

I started loading cast for a 9mm. My barrel slugs at .356.5". I'm using COWW water dropped with a BHN of 14 and lubed with 45-45-10.

I'm using a StormLake SS 40-9 conversion in a M&P full size 40. It has a tight chamber and not much freebore so I'm going to send it out for reaming,etc (throated, crowning). I know that I can seat my boolit deeper and adjust my charge but I like the idea of being able to seat forward if I chose.

Anyway, the Hornady 9mm expander flars the case mouth but doesn't go deep enough (without over flaring and damaging the case) to keep the case from swaging my bullet down from .358 to .356.


Will the Lyman "M" die help with this issue ? If so, do I need to get the .357 ?

[Thompsoncustom]

My cz barrel also slugs at .3565 and I use the lyman M die, I can't remember what expander I ended up with but the 9mm was to narrow, I think it was the .357 one which was to long to start with so I had to remove and reprofile the bottom half to make it more 9mm length.

[gloob]

Lyman standard is to make M die 2 mils smaller than jacketed, IIRC. IMO, even the 357 m die is slightly too small, assuming your bullets are at least 357 after sizing. E.g., when I bought 40SW M die, the plug measured 398 and it didn't work for me. I would assume a 357 M die is 355.

NOE gives several options for each caliber, rather than just one size. I would suggest you get NOE 38AP expander, the one which has 356 expander and 360 flare.* It goes deep enough to where the cast bullet seats, too. IMO, this is the perfect expander for 356 cast 9mm; it works fine with 355 jacketed bullets, too. You read that right. A 356 expander gives good neck tension on a 355 bullet.

*because this is the biggest one they make. Lee 38S&W plug is also about 356 in diameter, but slightly shorter. You just can't find any bigger expander, off the shelf. For 358 bullet, I would actually consider making a 358 expander, custom. Assuming my chamber is large enough to handle this. If you want to make your own custom plug but you don't have a lathe, I suggest M die and 40SW plug, because you can chuck the M plugs into a regular 3/8" drill. Put a few wraps of tape around the threads for protection. Rough grind it with dremel tool and cutting disc, shape/square with stone files/sanding blocks, and finish buff with leather and chromium oxide compound! Just check it with calipers and one of your bullets for reference. I suggest you stop as you hone in on the diameter of your sized boolits. You can always go smaller if you feel like it's not enough neck tension; I promise you won't.

[Kenstone]

This expander in a 9mm powder thru expander die
http://leeprecision.com/pm-expan-plg-38-s-w.html
here too
https://fsreloading.com/product.php?productid=4835
drop-in fit, expensive though...$3
works for me,

[Javater]

This expander in a 9mm powder thru expander die
http://leeprecision.com/pm-expan-plg-38-s-w.html
here too
https://fsreloading.com/product.php?productid=4835
drop-in fit, expensive though...$3
works for me,

+1 i use it now and it works. I just went through this.

[Moonie]

I use the 38 S&W in my 9mm lee die as well however I'd probably go with the NOE setup if I were to do it now. I got that expander before NOE started making theirs.

[Jal5]

I use that same 38 S&W expander too. Just works well in the Lee pte die

[handyman25]

I use a RCBS cowboy expander for the 38 special. My 9mm barrel mikes at .356. I polished the rcbs cowboy expander down to .3575. I size my bullets to .3575. I use the Lee factory crimp die to get the crimp I want. Works well for me.

[TXCOONDOG]

I appreciated the feedback all!

I ordered a Lee unversal case expanding die and the NOE .360x.356 expander plug.

PS: I've been using the Hornady seating die and thought about using the same die to crimp(just enough to remove the flare) in a seperate operation, if needed. Of coase, once I work out the swaging issue first.

I've never felt the need to crimp jacketed bullets. However, since I'm very new to using cast boolits and learned that I need to bell/flare the case to prevent shaving thought I would check (ask) with the forum.

Does my plan of only crimping (taper) 9mm cast enough to remove the bell/flare sound reasonable ?

If so, Which taper crimp die is preferred for a seperate operation and are there any that I should stay clear of ?

[ioon44]

"Does my plan of only crimping (taper) 9mm cast enough to remove the bell/flare sound reasonable ? "

Yes, I use the Hornady seating die and the Hornady taper crimp die just enough to remove the flare.

[Jal5]

I crimp just enough to taper the bell of the mouth.