Case length in 45-70

[cdschoonie]

I ran into a few cases of 45-70 measuring in and around 2.035. The manuals list minimum trim at 2.095 and max at 2.105. After some investigating, I realize these came with Hornady factory Leverevolution FTXs.

Im loading cast, 425 gr WFN, COAL shows 2.550. I’ve read threads on a few different forums, picked up by a google, which say to measure the chamber, but that the smaller Hornady FTX cases are not the main factor, but more of the COAL, my rifles chamber, and if they chamber well in the lever. I’m going to measure the chamber right now, but just wanted to ask, to see what responses I get while doing so. Especially with the price of 45-70 brass, there are 18 of them, so I want to use them if I can. What are y’all’s thoughts, use them or trash them?

 

[Okie4570]

I wouldn't hesitate to shoot them. 2.1 is what I run all my 4570 at.

 

[DRC458]

Use 'em.


.

 

[cdschoonie]

Ok, let’s shift gears and go back to chamber length. I got my chamber measuring at 2.620, it closed easily at 2.635, but subtracted .015. The mfg cartridges I have on hand measure 2.550 on avg, which is what load manuals list as optimal. Hornady FTX measure 2.595, all good so far. BUT, here’s where it gets funky, in order to get into the crimp groove on the bullets I bought, it brings them to a minimum seating of 2.535, maximum seat at 2.505.
So, I’m ok with these if they are accurate. My understanding is in order to get max accuracy, I should seat them as long as possible, which would be between 2.615 and 2.625.

Questions are…
1) First, can I still get good accuracy staying in the crimp groove at 2.520?
2) Do I really need to stay in the groove, or can I seat and roll them outside the groove?
3) Am I looking too much into this? In other words, should I just go with what they give me?

Here’s at pic of them. In front is from the new bullets. Far left is a mfg load, 2.551. 2nd from left is from my first loading, 2.552. 3rd from left is Hornady FTX. Far right is the dummy I measured the chamber with, 2.620 (it measured 2.635 to close in the chamber, I pushed it more so I can use it later for reference). Notice the crimp groove on the last one, which is what I’m loading now.
Any help is graciously appreciated!