I'm shooting the same rifle. 50 gr v-max, 25.5gr Benchmark, Win brass, CCI Primers, 2.250 oal. Less than .5 inch spread at 100yds. This was the first batch I reloaded and I can't find any reason to try anything else.
I've also found that Black Hills ammo has a 50gr match hollow point that works wonders for plinking. Shoots about 3/8 inch low at 100 yds, and almost as accurate as my reloads. I find them at Gander Mountain pretty cheap, I think $11 for box of 50.
Haven't noticed any changes when barrel is hot. I just know that once you clean it well, you have to shoot about 5 rounds through it to regain accuracy.
Mac