Crimping 45-70 or other Strait walled caseings

leonard

leonard

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Just wondering what other peoples results are on the amount of crimp used for 45-70 strait wall case loads.
using a RCBS Die here.
 
You only need to crimp any cartridge when using hot loads. Although, if you're shooting a lever action a light crimp will keep the bullets in place under recoil while in the mag. Otherwise, a crimp isn't needed.
 
I always crimp hard into the crimp groove provided on Heavy cast bullets in my smokeless 45/70s, I crimp in a sep. operation, these are usually heavy loads with 480gr bullets and i don't want any problems on the bear stand.
 
anyone experiance alot of difference doing lighter to heavy crimp? Ive been doing Heavy Crimps myself have played with lighter crimp but it was a close call.. could have been my shooting on that day close.
 
I prefer a heavy crimp in my .444 and 45/70's especially with cast bullets...my particular rifles obtain better accuracy than when the same load is uncrimped..
I crimp useing the Lee crimp die and its a seperate operation after all bullets have been seated with the rcbs dies
 
I would not crimp is if I was loading the ammunition solely for use in a falling block single shot. I would seat the bullet to contact the rifling, and because there would be no camming action from a bolt to cause the bullet to stick, and because there would be no magazine to contend with, crimping would offer no advantage. When loading for any repeater, I would crimp.
 
When loading in my Sharps 45/70 if i crimp my accuracy is lousy, crimping lightly just enough to hold the bullet got me 3 1/2 to 4 inches and no crimp is 1 1/4 on a really good day and 1 1/2 half most of the time. Thats 68 grains of Goex compressed .2 pushing a 555 grain 30-1 bullet from MT chambers
 
I agree with Boomer and delta....in my BPCR single shots the bullet is seated out into the lands and can't go further ahead unless it is fired and can't go back because it is sitting on compressed BP. I don't size my cases at all, seat the bullet by hand, only problem is taking an unfired round out of the chamber, but thats how my Highwall likes it.
 
sunray said:
You only need to crimp any cartridge when using hot loads. Although, if you're shooting a lever action a light crimp will keep the bullets in place under recoil while in the mag. Otherwise, a crimp isn't needed.
Click to expand...

That's the text book response, from all the jacketted crowd, it just doesn't apply to the 45-70.
There's a LOT more too it than using a tube fed lever gun.
Cast bullets don't generate as much bore friction, and thus SOME powders need that crimp to get started burning efficiently.
There is of course the aforementioned need, in a tube mag.
Then, there are those pesky fillers, that some of us use, to pack the case tight for consistent burns when using powders that occupy a small percentage of case room. Best crimp those too, don't want the oAL to grow.
The fact that we are working with a straight walled case, of thin wall, means that even with jacketted rounds, the grip it has on the bullet is not as strong as a more modern bottle neck design.
Lots of single shot guys, using the right loads, don't crimp, it's not always needed, but, as I said, there are considerations.
YES, I crimp ALL my 45-70 loads.
 
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Some single shot target shooters don't crimp, but adjust to touch the rifling. All that being said, they are target shooters, once the round is in the chamber, they will fire it. If bullet is contacting the rifling enough to engrave the bullet a powder spill might happen when extracted. The crimp might hold the bullet in place without a mess in this case. why the big debate over crimping? Try it if it helps great if not so what? Standard rule in lever, autos and other rough handling actions, crimp to eliminate bullet moving during shooting and or loading. What is one more step? this is a hobby not production to make money.
 
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