Lee 458 SOCOM seating die?

[Elkins45]

I tried to load for my new 458 SOCOM upper this week using the Lee 500 grain flat point. What I discovered is that I can’t set the die down far enough to turn in the mouth flare because the seater stem won’t back out far enough to seat the bullet. Even with the seater adjustment barely hanging on to the top thread it wanted to seat the bullet way too deep. I ended up screwing the die body way out of the press to seat the bullets, then removing the seater stem and screwing it back down to remove the crimp.

I figure I have two options: either buy a factory crimp die or drastically trim and then reshape the seater stem. I do find this very curious because I wasn’t seating the bullet particularly long. It still fit into a standard GI aluminum magazine. Has anyone else experienced this? Maybe they put the wrong seater stem into my particular set of dies?

 

[Ian]

I had big problems with that die and bullet too but have had two kids and half the sleep since then and will actually have to go look and see how I fixed it. Iirc I also had to grind the bottom of the die body to even be able to out a slight crimp on the case mouths.

Edit: I was mistaken, it wasn't the seating die that gave me trouble, my issue was working out a powder-thru die to work and expand the necks sufficiently. The seating die appears un-modified and all the stem threads are inside the die where it is adjusted. I tried a loaded cartridge in it and it goes almost all the way in with the shellholder in place. Maybe I swapped the seating stem from another die set, but it has not been modified.

 

[freebullet]

Seat & crimp seperate isn't always a bad thing. Sometimes do so with the 454. More consistent imo.

 

[Elkins45]

The floating seater stem is REALLY short but has a deep cavity to accept a long pointed bullet. The issue is that this particular bullet nose is wide enough that it hits the edges rather than going up into the stem even a little bit. I hesitate to trim it so I guess I’m going to have to turn a very short flat rod and drop it in there...or (and this just hit me) I can just pull the floating stem and have the bullet butt up against the bottom of the adjustment screw.

 

[RBHarter]

I've flipped that button a couple times to avoid the cone and use a flat point when it will work its great where it doesn't the cap doesn't have enough threads to stay in the die .

 

[Elkins45]

I've flipped that button a couple times to avoid the cone and use a flat point when it will work its great where it doesn't the cap doesn't have enough threads to stay in the die .

Normally that would work. For this particular die you can’t flip it because the diameter is too big for it to fit up inside the hollow top. If I get industrious I will turn one, but there’s a much better chance I will just cut a short section of dowel and jam it into the hole.

 

[JWFilips]

No Experience with the 458 SOCOM ( Except I have shot a friends one one for 3 shots ....Full house! My body never fore gave me!) But many times I too flip the buttons around to flat point and as I'm seating I spin the cartrige around 3 or four times slowly to even out the pressure as the bullet goes into the neck

 

[Intheshop]

Just throwing some numbers Elkins,as a data point.

Lee .45 ACP dies from the late 70's,early 80's.

I've been making seater stems this a.m. to register on the edge or rim of a Lee 185swc bullet that has been run through a custom top punch (Lyman 4500) that refines this as cast edge.

The factory stem came out of my die @.443 OD and from the 1/2" stop rim down is a nominal 1.00".

I started with the new one @.450,better but not close enough for what I'm trying for.

Taking an educated guess(wiggle @.450) ,went with .455" and is a smooth sliding fit. The nice thing turning these is; "die in hand". Not only do you NOT have to take the stem out of the chuck..... once you get to a sliding fit,you put the die up on it,take lathe out of gear and spin the chuck. You'll see very quickly how "inline" Lee got.

Net result was, .012" is how much slop there was in "my" die on stem diameter.