45-70 case length.

[CaptnJack]

Howdy again.
This is all kind of new to me so bear with me. Here is what I have. I have a bunch of cases that are not fireformed to my rifle. They have been fired though. I just resized them. They most all measure 2.095-2.010 I have a chamber cast that reads right around 2.125 >see photo. I will be using a 540gr.PP bullet. I guess I am asking to fit this into my chamber what do I need to do next? Do I need to lengthen the case first or fireform them to my rifle first? Also How much clearance should I give the case to chamber clearance? Just not sure which way to go from here?
And yes I am looking at precision shooting down the road just need to get the basics right and the load right first.

[Lumpy Grits]

2.010 is way to short.
I trim to 2.090 and never let the case get past 2.105, for the .45-70.
Gary

[bruce m]

jack, you have illustrated a point extremely well.
when the big red light comes on, your bullet will take the exact dimensions of that lead in your photo.
then it will start to move, going into the barrel and then out the muzzle.the part of the bullet that is expanded into space available in front of the case is swaged back down in this process.
bumping up, and then swaging back down, are both opportunities for something to get out of line or atherwise go wrong, and reduce accuracy potential.
you cannot avoid this issue in the transition area, but anywhere else, the case length can be controlled such that an obturated case goes full length of the chamber.
this is why sizing cases is to be avoided.
a sized case is longer than an unsized one, so you have to cut it too short for obturated length, just so it will fit the chamber.
the best rule for accuracy is to fill any space with bullet, thus minimizing bumpup.
one area to eliminate problems.
this equates to a bullet that will slide into a fired case.
whatever, 0.025 is way too much gap. this is excessive for smokeless chambers with jacketed bullets, and way out there for alloy.
doing what you have done is time well spent, as you know exactly which length to stretch fireformed cases to.
keep safe,
bruce.

[bruce m]

i would like to add.
where that slug is at the case mouth demonstrates that care of cases in this area is critical.
the alloy has forced to the shape of the case, and in doing so can actually cut the patch.
this could expose you to serious leading.
as well as case prep, alloys of 16:1 or harder will reduce the possibility of this happening.
keep safe,
bruce.

[CaptnJack]

i would like to add.
where that slug is at the case mouth demonstrates that care of cases in this area is critical.
the alloy has forced to the shape of the case, and in doing so can actually cut the patch.
this could expose you to serious leading.
as well as case prep, alloys of 16:1 or harder will reduce the possibility of this happening.
keep safe,
bruce.

Thanks, Bruce for info.

[CaptnJack]

More questions: Can you fireform a case without using a bullet by just using some powder and wads? Suggestions?
Also, It seems I need to stretch my case at least .020-.025 will the Buffalo Arms 45 case stretcher work for this., has anyone used one for this? If I go to go with one from Kal-Max Case Stretching Jig it would be cheaper to go with 45-90 new cases.

[Lumpy Grits]

A full load with bullet is the best way.
That said-I do FL size my .45-70 cases in a .45-90 FL die.
I found that I see the smallest T.I.R. run-out of the bullet, buy doing so.
Also keeps from over working the 'brass', as I only shoot GG bullets.............

Gary

[bruce m]

jack, if you intend using bore dia pp bullets, and you have a greaser chamber, you could consider norma 45x 3 1/4 cases cut back.
this will give you thicker necks, which will fill some of the excess neck diameter in the chamber.
keep safe,
bruce.

[Coltsmoke]

Jack, the BA case stretcher will work for you, I have one and have used it many times. Loaned it to my shooting partner, worked fine for him also.

[Coltsmoke]

Lumpy, what does that do, size the back half of the case and not so much on the mouth end of the case? What is the inside dia. of the case mouth when done this way?

[Lumpy Grits]

Lumpy, what does that do, size the back half of the case and not so much on the mouth end of the case? What is the inside dia. of the case mouth when done this way?

I found it only sizes the case down .002-.003 all around.
Works the case less-cases don't 'grow' much in OAL. Better fit into chamber.
I use a .45-110 FL size die, for my .45-90 cases.
Gary

[CaptnJack]

Jack, the BA case stretcher will work for you, I have one and have used it many times. Loaned it to my shooting partner, worked fine for him also.

Thanks will get on and give it a try.

[CaptnJack]

jack, if you intend using bore dia pp bullets, and you have a greaser chamber, you could consider norma 45x 3 1/4 cases cut back.
this will give you thicker necks, which will fill some of the excess neck diameter in the chamber.
keep safe,
bruce.

Thanks again

[bruce m]

jack,
do sme research on dual diameter pp bullets.
those who have tried them have gotten good results with bore dia pp bullets in greaser chambers.
they work because you are filling all space avilable with bullet as you should for best target accuracy.
this saves alloy movenent from bore diameter up to over groove diameter in the case neck on firing.
sizing brass might be necessary for hunting ammo in cartridge belts, but will never shoot as well as correctly fitted bullets in fireformed brass.
the bonus is you just have to reprime, charge the case and seat the bullet with you fingers, job done.
of late distant thuder has written a lot on this subject, but beltfed/arnie has also proven its benefits.
i myself have fired thousands of rounds with such bullets from 200 to 1000 yds without a failure and good accuracy.
keep safe,
bruce.

[CaptnJack]

Ordered one of those mini chops saw just waiting for it to arrive. I didn't have a lot to do so I made a chamber cast of my 45-70 and my 45-110 today from some Cerrosafe. I just was not satisfied with the impact impression I got on the 45-70. I have one of those magnifier headbands with light the jewelers use. So I have done some measuring again with the new chamber cast and came up with a 2.107 and measured some of the brass I have >it's fired but not in my rifle and there measuring from 2.099-2.096. looking at the picture and maybe I am wrong it looks like the used brass I have will work ok without stretching it any ? Am I right on this?
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