So this is a brand new barrel on a Ruger M77 that began life as a 300 wm. It is a 26" Krieger 4 groove 7.5" twist #5 plus contour chambered in SAAMI spec .264 Winchester Magnum. Stock is a Stocky's Pro-Varmint with adjustable cheek rest, and I pillar bedded it. I wanted to document my load workup in this rifle, and post my data for any of those that may be interested. I will eventually test out the 156 EOL's when they come out, and possibly throat this rifle longer for the 156's. Right now, the 147 ELD'M seated .010" off is WAY in there, the base of the bearing surface of the bullet is even with the body/shoulder junction. I have heard people say you won't gain anything from throating a .264 WM, due to the fact that you won't fill the case up even with slow burning powder, but the max load I found was 100% fill, and the 3 above that were slightly compressed. Also....if you seat a bullet farther out, you are increasing the case capacity of the cartridge, plain and simple. A 26 Nosler shoots faster than a .264 win mag because it has a larger case capacity....and when you have as much room to move the bullet out as this throat does.....how can it not improve performance? The increase in capacity will be significant. Anyway, I digress.....Here is my first pressure load work up. The bore was treated with HBN after a good cleaning, as the Smith fired 1 test round through it before I got it back. Loads are 2 rounds fired at 60 and 61 grains, and 1 round fired at all other charges. I did this to ensure the bore was properly HBN treated prior to working up for pressure, so I would get the most accurate data I could. These are rounds 2-16 fired through this rifle. .264 win mag 7mm rm Federal brass, necked down to .264 CCI 250 Primer HBN coated 147 eld-m, seated .010" off a saami spec throat (oal 3.330") Retumbo powder All loads chronoed w/magneto speed 60 - 2877 fps / 2832 fps 61 - 2876 fps / 2862 fps 62 - 2915 fps 63 - 2938 fps 64 - 2994 fps 65 - 3044 fps 66 - 3077 fps 67 - 3118 fps 68 - 3167 fps 69 - 3204 fps 70 - 3244 fps and first sign of pressure, faint ejector mark 71 - 3292 fps and slightly heavier ejector mark 72 - 3342 fps and identical ejector mark to 71, and first signs of heavier bolt lift. I noticed my first round fired was higher speed than the second load of the same charge. I have read that the first round fired through an HBN coated barrel will be slightly higher pressure/velocity than following rounds. I guess this shows it to be true, at least for this rifle. So it looks like 3200 fps will be about max for this set up, and I'm happy with that. At my elevation, this load still retains 1516 ft. lbs. of energy and 2156 fps at 1000 yds, and only has 1.1 mils of wind drift in a 10 mph. That is on par with a 28 nosler shooting a 195 EOL at 3100 for everything but energy, wind would be 1.0 mills of drift and 2158 fps in the same conditions. As I continue load work up I will update this thread. I know that I had to start with little to no data to go off of with the components I wanted to use, so I figure this may help someone.