45-70 trim length consistency needed for roll crimp

[northny]

I haven’t reloaded 45-70 in maybe 20 years, so it’s like starting over.

I will be roll crimping ( lee die) as a separate step after seating. The brass I have was trimmed back when I used a rcbs trimmer, and is not as uniform as I get now with l.e. Wilson set up. I have three lots of brass (50 pieces each lot). Each lot has 88% +/- .003 in length. The other pieces are equally longer and shorter

I will be shooting this in a Marlin lever gun so I do want a crimp.

My question is how uniform does the length need to be for a good crimp?

(note: original post had +/- .0003 in length. I edited to correct)

 

[38ExtraSpecial]

I haven’t reloaded 45-70 in maybe 20 years, so it’s like starting over.

I will be roll crimping ( lee die) as a separate step after seating. The brass I have was trimmed back when I used a rcbs trimmer, and is not as uniform as I get now with l.e. Wilson set up. I have three lots of brass (50 pieces each lot). Each lot has 88% +/- .0003 in length. The other pieces are equally longer and shorter

I will be shooting this in a Marlin lever gun so I do want a crimp.

My question is how uniform does the length need to be for a good crimp?

I try to keep them within about .010-.015 total. If you’re running 2.095 and 2.105 you probably won’t notice much of a difference. Much more than that and you will.

 

[Broc]

0.0003 is nothing. Do you have an extra "0"?

I never trimmed mine. Reloaded over 10 times.

I trimmed some brass I bought for the Sharps when I first got them because some of them were 0.001 longer. But I have around 500 more casings I never trimmed. Those are used for the levers, revolvers and bolt actions.

I full length size every time except the Sharps brass, that one is fire formed.

Side note:
I also stopped cleaning the brass. I just lube, size, clean the lube with a paper towel and load it.

PS: I do the same for 6.5cm and I noticed no accuracy issues (I do trim 6.5), I tested new vs 1 time fired and cleaned vs 2 times fired and dirty vs 3 times fired and dirty. The brand new brass had slightly larger groups than the 1, 2 and 3 times reloaded.

 

[1903Collector]

If my cases are +/- a thousandth thats good enough for me otherwise your just going to give yourself an aneurysm. I'll let them go more than that if I'm not crimping.

 

[northny]

0.0003 is nothing. Do you have an extra "0"?

well cr%p. Yes I do have an extra zero in there.

Ive got a lot of 50 Winchester brass that range from 2.095 to 2.100 centered around 2.097. I’ll Set up crimp on 2.097 and give it a go

 

[Asaltweapon]

I was going to ask what was he using to measure .0003.

 

[paul73]

I was going to ask what was he using to measure .0003.

i would guess he meant .003, and it is very doable by using a case gauge and a trimmer, as you just make it sit flush with the gauge, no need to measure anything.

 

[45BPCR]

Get a Lee factory crimp die.

Amazon product ASIN B000NOQIRWView: https://www.amazon.com/LEE-PRECISION-Factory-Crimp-Die/dp/B000NOQIRW

 

[Broc]

Get a Lee factory crimp die.

Amazon product ASIN B000NOQIRWView: https://www.amazon.com/LEE-PRECISION-Factory-Crimp-Die/dp/B000NOQIRW

I think that is what I use.

 

[pastera]

Get a Lee factory crimp die.

Amazon product ASIN B000NOQIRWView: https://www.amazon.com/LEE-PRECISION-Factory-Crimp-Die/dp/B000NOQIRW

Lee factory crimp dies are very seldom the answer
However the Lee 45-70 die is a collet type which is a good solution to small case length variations
Any FCD with a carbide sizing ring should be avoided like a plague.

 

[38ExtraSpecial]

Lee factory crimp dies are very seldom the answer
However the Lee 45-70 die is a collet type which is a good solution to small case length variations
Any FCD with a carbide sizing ring should be avoided like a plague.

Exactly what I was going to say. This is a collet crimp die. I wish they would change the name on one or the other.

 

[45BPCR]

The factory crimp die has 4 internal sections that "squeeze" the case mouth into the cannalure unlike a roll crimp.
It's not as dependent on case length as a roll or taper crimp.
I think we're all talking about the same Lee die however.

Lee Precision, Inc.. Collet Style Crimp Die

Collet Style Crimp Die. Incorporates a collet to apply a rifle type crimp to the case. Makes these very difficult to crimp cartridges a delight to reload. Bullets do not need a crimp groove, as the collet is so powerful it will form one. NOTE: This die is not carbide.

www.leeprecision.com

 

[Asaltweapon]

i would guess he meant .003, and it is very doable by using a case gauge and a trimmer, as you just make it sit flush with the gauge, no need to measure anything.

To be clear I was rather sure what he meant.

 

[ddeck]

Exactly what I was going to say. This is a collet crimp die. I wish they would change the name on one or the other.

I think we had this same confusion in another thread (cast bullets). The Lee Pistol FCD has a carbide sizing ring whereas the Rifle ones are simply the collet type.

I had to buy another company's crimping die for pistol rounds that did not include the carbide resizing ring.