Ok took the 260L out today. It has an 18" barrel and wanted to report some of the results since several of you were nice enough to share your load data.
Remington factory ammo, 140 gr core-lokt that per their data has a muzzle velocity of 2750. Out of my riffle it was 2449, pretty large change but no data on barrel length on their data.
Hand loads were 40gr of H4350, rem brass with a Hornady 140gr AMAX bullet. Came in at 2508 out of my riffle. Looks like there is some room to build here!