45 70 shell mouth crumpeling...

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Hi everyone,
This happened to a couple cartridges when seating the bullet and crimping also had a couple seat crooked???
Never happened before I did use a bit of case lube and annealed the cases this time but was careful not to heat them
too much. any ideas ??
 
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Looks like over crimping. If your brass trim lengths are not within a couple thou then this can happen randomly with long brass. You can crimp separately after seating by backing out the seating plug, screwing the die down onto a loaded round, lower the ram and turn the die in your preferred amount. Then run the ram up to crimp. Repeat for each round. This gives a more consistent roll crimp when your trim lengths are varied too much. As for bullets seating crooked, here's a tip that will help. Seat the bullet about 1/8" then remove the round from the press. If your bullet has a cannelure down near the base use it as a guide to stand the bullet up straight by hand. If it does not have a cannelure then look down at the round from the top and rotate it to find which side the bullet leans to. Same deal, straighten it by hand then throw it back in the press and seat it fully. Any slight bulging created at first will smooth out when the bullet seats squarely. I now use a classic Lee loader to start bullets in the case when loading .45-70. It works similar to Lee's dead length seating dies and seats bullets nice and straight. Then I finish seating and crimping in the press.
 
what dies are you using?? back the seating die out until no crimp, adjust your seat depth, and get a lee factory crimp die esp. if you're using a tube mag. The lee factory crimp die will give a much better crimp with almost no chance of collapsing the case.
 
Thanks for the replies,
I will try separate operations, and next time I will trim all
my brass to the same size - they did vary some in length.
Im using RCBS dies -- are the LEE better?
 
The RCBS dies are great. The key for me is to screw the die in until it touches the case mouth ( with the seater stem backed way off. ). Then unscrew the die about a full turn. Then adjust the bullet seating depth with the stem.

You are definitely right in that it's a good idea of all of the brass is the same length.

Chris.
 
Happened to me a couple times when I first started reloading a year ago.
I'd check with a bullet to make sure your expanding die is going deep enough, and seat and crimp separately.
 
I have a set of RCBS and a set of Lee dies for this cartridge. I haven't used the lee ones except the seater and the crimp die. I was told by a guy that reloaded extensively for the 45-70 that there's little need to trim the cases as they're more likely to shrink rather than lengthen... Still conducting that experiment.
I'll describe what I did with the rcbs dies. Deprime and full size as normal. The expander die I set so that the mouth of the bullet case is just a little bit bigger than the bullet to be seated... I want to minimize working the case mouth. To set my seating die, I raise the ram all the way with a case on it, and screw the seater die in until it's stiff to turn by hand, and lower the ram and screw the die in another half turn. That's about enough to close the flare from the expander die. Then I run a round ready to seat the bullet into the die, and adjust the bullet seat depth to close to far enough, and afterwards lower it a quarter of a turn, check, etc., until desired seating depth is reached. Then is set up the crimp die. You can set it for full crimp, or you can back to die off a little at a time to make it do a light crimp.
I found that using the seating die to crimp in any case makes for a lot of unnecessary grief and wrecked cases. Easier and a lot less grief to use a proper crimp die.
 
amosfella, Every time I FL size my cases stretch, never shrink. They all stretch slightly different amounts so there is no consistency in length after sizing. I'd ask your buddy for clarification if that's really what he said, unless he was talking about pistol brass. As for expanding, I've had good success expanding to bullet dia. with jacketed bullets. The heel radius does the rest and I haven't crushed a case. I also crimp and seat in the same operation. Trimming after sizing with a good trimmer that gives consistent lengths eliminates the OP's problem too and saves me the extra step.
 
The OP only had this with a couple of cases in his batch. It's a case length problem. Trim cases first to proper length, then the crimp function of the seating die won't cause this.

OP, I believe your friend is mistaken. Although this is not a traditional bottleneck case, it isn't straight-walled like a pistol case is, therefore, there is gonna be some stretching involved during resizing. Can't be helped, just the nature of the beast.

Ted
 
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One thing to consider with the 45-70 case is that they are used very differently in a lot of instances. I have loaded 100's of them, seating and crimping in the same operation and have never had a 'crinkle". All of my 45-70 shooting is at old B/P velocities & pressures, however a lot of people like to use a 45-70 as a .458 Win mag lever gun. If you use your brass at high pressures they will stretch more than low pressure loadings, requiring more judicious trimming.
 
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