300WM and 210 LR Accubond
This post is partly to provide info to anyone who may be planning on using this bullet/caliber combo and also to get some feedback on my results.
Rifle: Weatherby Vanguard, .300 Win Mag, 24-inch barrel, 1:10 twist, I pillar-bedded the action and floated the barrel.
Bullet: 210 gr Nosler Long Range Accubond
Primer: Federal GM215M
Chrono used on all shots
To start I did a ladder test at 300 yards with charges from 73-77.9 gr at 0.7 gr increments. This was done with new brass. There were no signs of pressure throughout this test. The results showed a node at ~2650 fps and one at ~2800 fps.
Next range session I shot for 3-shot groups at 200 yards with charges from 76.6 gr to 78.2 gr at 0.4 gr increments. This was still new brass. Accuracy was a bit discouraging although the 77, 77.4, 77.8 groups all had 2 shots close together with a third flier. 78.2 charge showed very slight primer flattening but no extractor marks or noticeable difference in the bolt lift.
3rd range session I again shot 3-shot groups at 200 yards. This time I had once fired brass, full-length resized to bump the shoulder back 0.002". Charges were from 76.8 to 78 gr at 0.4 gr increments. 78 gr also showed slight primer flattening with no other pressure signs. Best group was just under 0.8" at 200 yards with 77.6 gr. Velocities for the 3 shots at 77.6 gr were 2818, 2836, 2818. Considering that this is a factory rifle with only the mods I did I think that 0.4 moa is excellent if I can repeat it.
Next step will be to shoot 5-shot groups at 200 yards with 0.1 gr power increments from 77.4 to 77.8 gr to see if the results can be repeated.
Finally to my question: Do you think that my load is too close to max, considering the pressure signs that I started to see at 78 and 78.2 gr charges? Range is somewhere around 1500 ft in elevation and temps were in the 90s. Hunting situation will be from conditions similar to the range all the way up to 10,000 ft and down to 0 degrees.
Thanks for your input!