I have the Ruger M77VT in 25/06. I have used the 75gr hp and am now trying the 75gr vmax. The hp's did struggle out past 200 to stay on target I am hoping the vmax with the boattail will do better out a little further. If you want to do some really long range 25 cal shooting, 300+ yard shots, go for the 100gr or larger bullets. I have had really good results with both sierra and nosler out to 500yds in this weight. At 500yds if you miss the first shot the prairie dogs don't really know what is happening and I often get a chance to adjust and take them with the second shot.
Here is some of my load data, some may not be at a blistering past as I was more concerned with accuracy since a dead dog is a dead dog no matter what the bullet speed. Though it is pretty dramatic seeing a dog stretched out in pieces and flying 10 feet into the air after getting hit with a ballistic tip.
75gr Hornady HP, IMR 4350 54.5gr, no velocity data
75gr Hornady HP, IMR 4831 58.2gr, 3350fps
I don't have any data on the 75gr Hornady Vmax yet.
100gr Nosler ballistic tip, IMR 4831 51gr, 3020fps This load rugularly produces .75 in groups and smaller.
I have had this rifle pillar bedded and have had a muzzle brake installed, so I can spot my own shots and watch the action at impact. The .75 in groups previously mentioned was before the pillar bedding, I have had some down as tight as .42 since the work. Hope some of this helps out.