Max Pressure for .30-06 vs. 6.5-06/270/338-06
First, some background:
The rifle in question is a Win M70 Supergrade in .30-06, one of the recent SC-built rifles. It has a 24" barrel. I've been experimenting with the 167 Lapua Scenar, the 175 and 190 SMK, and the 208 A-MAX. So far, I've tried H4350 and RL-22 but also have some IMR4350 to try at some point. A max COL of 3.395" allows it to feed 100% reliably from the mag. Combined with this rifle's fairly short throat, this mag length lets me seat all four of these bullets to within .010" of kissing the lands except the 208 for which I can get to within about .025". I'm using Lapua brass (now all once-fired) and Magtech primers. I recently picked up a chronograph (Shooting Chrony F1) but have yet to use it.
Now, the topic at hand:
In searching the various relaoding manuals and web forums for long range loads to develop in this rifle, I've noticed some folks use 65,000 psi as the max pressure for their handloads rather than the SAAMI max of 60,000 psi. This seems to be based on the fact that three direct descentents of the .30-06 (6.5-06, .270 Win, and .338-06) all use the same case head and web dimensions as their older relative but have a SAAMI max of 65,000 psi.
Since case strength (keeping the primer pockets tight) is the limiting factor in determining max chamber pressure for modern bolt action rifles, this appears to be a reasonable practice. Without a doubt, it will result in decreased case life and perhaps silghtly shorter barrel life (probably a nit) but it certainly doesn't seem dangerous.
What are your thoughts and/or experiences on this?
Edited to add:
I do have QuickLoad and consider it a guide but not a replacement for actual data.
Last edited by chuckhammer; 07-21-2010 at 10:06 PM.