CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.
Thanks for all the responses so far, especially those that actually address the question in the OP.
I asked about this because I am starting to work up loads using a different method than I have been using. In a nutshell, the new method involves finding the load that shows signs of over-pressure (working up one cartridge at a time, with about a 1% increase in charge for each cartridge), then working down from there using more normal groups (3 or 5 shots). When working up you will eventually have a cartridge that flattens or blows a primer or something...you know to start your "work down" one increment below that load.
I would like to use this method with my Marlin. But because I figured the bolt would let go (as SHR970 indicated) before I saw any traditional signs of pressure, I have been working up loads in a more-or-less normal fashion...5-shot groups, going up half a grain at a time. Using Starline brass, Hornady 300-grain JHP's, CCI large rifle non-magnum primers, and IMR 3031. I am up to 53.5 grains and my shoulder is OK so far. I figure my shoulder will give out before I hit book max (56.9 grains according to Hornady 7th) but I guess we'll see. If it doesn't give out then I guess I should just stop there and see what I have.
For comparison, using the new method I found that using neck-sized Remington brass, Hornady 168-grain Match bullets, CCI large rifle non-magnum primers, and AA 2520 I can load up to 47.5 grains of powder. This is a full grain beyond the hottest book max I could find. 47.8 causes gas leakage around the primer. This is in my Weatherby Vanguard .308.
I also found that using neck-sized Remington brass, Hornady 40-grain Z-Max bullets, CCI large rifle non-magnum primers, and Varget I can load 42.8 grains of powder. This is 2.8 grains beyond the hottest book max I could find. This is in my Ruger No. 1 .22-250. I could probably push it harder, but I don't have any more room in the case, and I am already using a drop tube. So I will start at 42.8 and work down.
Last edited by Unclenick; May 7, 2012 at 02:45 PM.