I have a contender chambered in 30/30 ack imp an I was looking at load data over the weekend for both the 30-30 and the 30-40 Krag and noticed that the 30-30 is loaded 2000 cup lower (38,000 to 40,000). I also noticed that that for one particular powder and source (IMR4064) the max charge was 33.3 for the 30-30 and 44.0 for the Krag. I was hoping to get an answer as to why. I am assuming of course that 10 plus grains would account for 2000 CUP of pressure and more. I am asking because I do have a bit of extra room in the Ackley version of the 30-30 that I have. I know I can’t cram 10 more grains and make it a krag or for that matter any version of a hot rod 30 cal. But like most reloaders I am trying to make ammo that is in some way better than what is available over the counter, whether it is a gain in accuracy, velocity or both.

Thanks Love22Hunt

First the 30-40 has a case capacity that is 26.8% larger. Second as you stated the pressure max is higher for the 30-40. My data calls it 47125 vs 42,000psi. The 30-30 was designed for a lever action the 30-40 a bolt. Could you load the 30-30 to a slighty higher pressure, sure a 7-30 waters is loaded to 45,000. Major issue I see is thin 30-30 brass being loaded much more than 45,000 and the Contender is not an Encore.

With my face next to it I wouldn't load beyond 45,000.

Thanks Paul,

I appreciate and value your $.02 worth. With reloading its about trying a load and recording the data, every gun/rifle will let you know what recipe it likes.

The 42 kpsi rings a bell with me. I'm thinking 42-44 kpsi is tops.

Mike Bellm has an excellent write up on pressures in the Contender this is a must read for any serious Contender reloader. Try googling it up.

IRRC, the limiting factor on the frame/action is the total force trying to open the frame up. You exceed this force and you "stretch" the frame.

So, a larger case head diameter should have a lower max pressure than a smaller one. The .30-30 should have a higher max pressure than the .30-40 in the Contender.

I googled 'em up from home, cuz they won't let me do it at work (go figure)

http://www.bellmtcs.com/FAQ/3030option.htm

This one talks about max pressure in the Contender:

http://www.bellmtcs.com/FAQ/max_pressures.htm

All his articles:

http://www.bellmtcs.com/TOC.htm

Mike is a personal friend of mine...he's a great guy and knows his stuff...I am sure if you drop him an email, which is highlighted on his web site he will usually answer it.. he is that personable...