How important is a crimp on 500 S&W?


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IMtheNRA
November 24, 2007, 05:02 AM
I picked up a set of Lee dies and loaded a few rounds today. I used Sierra 400-grain JSP bullets to make some test rounds with 34, 36, 38 grains of H110 in once-fired Magtech brass with CCI large rifle primers. OAL is 2.050". All this data is straight from Hodgdon's site.

I could not set the seating die to seat and simultaneously crimp the rounds like I usually do when loading .357 and .44 mag. This round is so long that I kept running out of bullet seating depth adjustment. Maybe I just could not figure out how to use this die...

I compared the crimp-less rounds I made to some of my 400-grain Magtech ammo and the Magtech rounds don't seem to be crimped either.

Can I safely use these rounds without crimping them or should I remove the seating adjustment screw and crimp as the last step?

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Grumulkin
November 24, 2007, 09:22 AM
If you are shooting these in a single shot firearm like an Encore you don't need to crimp them; if shooting them in a revolver, you do unless you want to shoot them one at a time. Crimp as a last step if you need to crimp.

It looks like you've stumbled on the best bullet I've found for the 500 S&W. Over H110/Win. 296 mine will do 1 to 1.5 inch 3 shot groups at 100 yards with that bullet.

dmftoy1
November 24, 2007, 11:27 AM
My experience has been that the crimp is VERY important when using H110 . ..other powders (light loads) I've only used a very light crimp.

FWIW.

Regards,
Dave

IMtheNRA
November 24, 2007, 01:22 PM
Thank you for the replies. I made only four of each to try, so I'll shoot them one at a time. However, I do intend to disassemble the die and use it to crimp the rounds. I have a couple of follow up questions.

Since my only factory manufactured rounds appear to be not crimped, I'm having trouble imagining just how much crimp to apply. With my .357/.44 rounds, I adjusted the dies until the crimps looked like my Winchester white box rounds. My method is very unscientific, but the reloading manuals did not address crimping technique.

Should I simply imagine this to be an oversize .44 round and crimp accordingly? How do I know if I end up with too much or too little crimp?

Is my choice of bullet too large to seat and crimp with the Lee die in one operation?

:)

FLORIDA KEVIN
November 24, 2007, 01:57 PM
I would think that after you had loaded all the bullets and seated them ,you could back off the seating adjustment and tighten the crimp down then go over and crimp as much as you need to as a spearate step ! If anybody has a better idea i would love to hear it !

rcmodel
November 24, 2007, 02:02 PM
Try adjusting the die like this:

*Put an empty sized case in the shell holder and run the ram up.

*Back out the seating stem several turns.

*Screw in the seating die until you feel the crimping section contact the mouth of the case.

*Now charge the case and adjust the seating stem down to seat the bullet until the case mouth is just at the bottom of the bullet cannelure.

*Lock the seating stem down tight.

*Now, turn the whole die in a 1/4 turn and run the ram up again. You should see a light crimp start to form.

*Continue to adjust the die down a little at a time until the crimp is rolled into the cannelure and the crimp is touching the front of the cannelure.

*If you still need more crimp, back the seating stem off a little and screw the die in a little more.

I would think you will need a firm crimp not only to get a good powder burn, but also to keep bullets from backing out under recoil and locking up the cylinder.

http://i81.photobucket.com/albums/j219/rcmodel/KTOG/1224.gif
rcmodel

dmftoy1
November 24, 2007, 03:46 PM
I seat/crimp in the same step using the instructions for the die. (Typically as stated above)

In terms of the proper amount of crimp, probably the easiest way to get it to take one of your 44 Magnum's, measure the difference between the crimp and the casing using your calipers and have a similiar amount for your .50 S&W. I always tend to do it by eyeballing it, but it's subjective and like you said it's easier if you have factory ammo sitting around.

Grumulkin
November 24, 2007, 04:11 PM
You guys are making much to much about crimping. Compared to the amount of pressure generated in a cartridge when fired and the amount of pressure it takes to move a bullet down a gun barrel, the restrictive amount of force any amount of crimp you can apply to a bullet without deforming the case will cause is minuscule. I have not found crimping necessary for a good powder burn even with H110 and, in fact, I load my 500 S&W with H110 and no crimp. There is little if any residue in the barrel with this load and I get excellent accuracy (that is if you call 1 to 1.5 inch 100 yard 3 shot groups excellent).

The only reason to crimp is to keep the bullet from moving in the case under recoil, i.e., to make a more durable cartridge. When I crimp, I eyeball it and make sure the mouth of the case is tucked into the cannelure without deforming the bullet.

IMtheNRA
November 24, 2007, 08:10 PM
Thanks again for all the great feedback and the helpful instructions.

It turns out, there is plenty of room in the Lee die to seat the bullet and crimp at the same time. I just did not figure that our last night.

I very slightly crimped my test rounds before I went to the range this morning. I did not want to overdo it, so the case mouth measurement on the finished rounds was reduced only .002"

I loaded and fired each round individually, but I kept a test round in the cylinder to see if the bullet backed out. Sure enough, after four rounds, the bullet in the test round slid out so that almost the entire cannelure was now visible.

Obviously, I did not crimp enough and to answer my own question, crimping is an important step in 500S&W reloading. My next attempt will be so that my rounds are crimped "to the extent that my .44mag rounds are", if that makes any sense...

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