Author Topic: 45/70 BC OAL with casts (Read 743 times)

jyuke · « **on:** June 05, 2006, 11:52:33 AM »

Just wondering if anyone has played with the Over All Lenths with cast bullets in the BCs or do you just stick with the normal 2.550?

Smokin Joe · « **Reply #1 on:** June 05, 2006, 12:37:25 PM »

In my B/C I use the Lee 500 3R at 2.885 and the Paul Jones Creedmore 535 at 2.895.
This puts 'em both .015 off the lands.

The Lee touches at 2.900, the Jones at 2.910

jyuke · « **Reply #2 on:** June 05, 2006, 12:49:55 PM »

Thank you that is great information, I was not sure how it worked for casts loads. Plan on keeping them slow.

Grizz_ · « **Reply #3 on:** June 05, 2006, 02:14:40 PM »

smokinjoe5150,

Wow, is that stock? I have not measured it but I don't think my BC has anything like that for a throat.

Grizz

Smokin Joe · « **Reply #4 on:** June 05, 2006, 02:31:51 PM »

It's not really the throat, it's the design of the bullet and it's "Bore Ride" section. You don't have to seat 'em that long, but I'm using black and I need all the space I can get.

Ed Hill · « **Reply #5 on:** June 05, 2006, 02:45:58 PM »

Wow! I put a Lee 405 hollow base in a fired shell, no crimp and left it long. Chambered it and closed the action, opened it and it measured 2.667. I figured that it was right against the lands with that bullet.
Ed

Smokin Joe · « **Reply #6 on:** June 05, 2006, 02:54:30 PM »

It probably is. The Creedmore and the Lee have a long sloping nose that allows the long seating.

lonewolf5348 · « **Reply #7 on:** June 08, 2006, 02:28:42 PM »

I find on my 45-70 B.C. it will chamber on a 500 grain cast bullet round nose at 2.725 and eject without any problems

John Boy · « **Reply #8 on:** June 15, 2006, 05:12:35 PM »

Jyuke - the OAL of the loaded cartridge is determined by the chamber depth and the distance from the end of the chamber to the end of the leade to the leading rifling cut.

The easiest way to measure the OAL for your favorite case and bullet is to:
... Measure the length of your favorite bullet
... Drop the bullet into the chamber and tap it with a dowel rod - it's now in the leade
... Take a depth measurement from the end of the chamber to the back of the bullet.

Add: bullet length + depth measurement = OAL of the reload

If you want the reload that is a 'jumper' - not in the leade, just back off the OAL to the length you want the bullet to jump

If you want to determine the proper length of the case that will fit in the chamber ...
One candle, one drop of wax on crimp of loaded cartridge, quick, into chamber and close action. Remove and see the end of the chamber where wax sticks to bullet and case.

I shoot many different bullets and use R-P's and W-W cases. Here are the BC OAL's for several of them:
Lyman 457123 - 2.712"
Victory PGT - 2.848"
Lyman 457661 - 3.152" (it's a bore rider)
DD/PRS Twin Groove - 2.587"

So, to answer your question and to achieve better accuracy... it all depends! :wink: