Finally had a chance to shoot the 250 at 100 yards...
I put 4 rounds of the 100g Hornady Custom factory ammo into 2.5 inches. The ammo chrongraphed 2788fps with single digit standard and average deviations.

I put 4 rounds of hand-loaded 117g Hornady RN (which is a shorter bullet than the 100g factory bullet above) ahead of 32.6g of IMR 4320. That load chronographed 2560fps and also had single digit standard and average deviations. Unfortunately, it went into a nice lengthy 7.5in string.

Much, much work to be done... :-(

On the up side, it really is a nice cartridge/rifle combo to shoot!