It would be helpful knowing what we are dealing with here before throwing out suggestions that may or may not be helpfull, Remington Mountain rifle one of the heavy barrel models type of glass, does the rifle shoot other bullets well?, so yes magnum primers may make a big difference, sometimes a change of brass can be most helpfull, I developed loads on at least 7 different rifles in this chambering all but one were sporter weight guns and all but one shot the ballistic tip especially well, Powders I now look to are RE22 RE25 H1000 win WMR if you happen to have any, and a old standby H4831, I'm more of a 257 Ackley fan as that particular rifle short light weight at 6 pounds hunt ready, bettrr fits my hunting style, my 06 is my designated antelope rifle occasional deer rifle and sometimes long range coyote gun, I got this gun about about 84 its a custom rifle built on a FN Supreme action Apex barrel with a nice peace of bastogne walnut, using book loading data I came up with a load of 54 grs of H4831 behind a Sierra 117 gr and 115 gr Nosler partition, I got my first chronograph I think in 81, Ive had 8 others since that time still have three of them so my readings were not a one off error, I was getting on average between 3220 and 3240 for the two bullet weights, years later when Re22 came along I found 56 grs of this powder increased my velocity by over 100fps with slightly improved accuracy, after running several accuracy test with Every primer available at the time by best accuracy came with cci 200 rifle primers, more years went by and along came RE25 I had no available data to work with but found 60 grs of this powder behind a 120 slug to be safe in my gun, I fired five cases a total of six times primers pockets were still snug, Tech's from both Barnes and Sierra felt that this load was safe in as long as the primers were tight, neither company at that time had any 25 06 data for Reloader 25, again velocity increased another 100 fps, I'm getting just over 3400 fps with the 115 gr partition, and again accuracy improved I fired a 10 shot group that measures 6/10th not bad for a sporter, with this powder accuracy came with the Winchester WLRM primer, by this time Nosler had introduced the ballistic tip, I dropped the Sierra in favour of the nosler, I found both the 100 and 115 bt printed to the same point of impact as the partion, the 100 gr left the muzzle at over 3500 fps, I eventually dropped that bullet as well as it made a real nasty mess of coyote pelts, and while out picking on Ron Johnson coyotes during deer season I ran across a medium sized 3 point blacktail, this buck was starring back at me at maybe 100 yds I hit him in the tearduct of his left eye, however I really felt the bullet should have blown the back of his skull off, the bullet never existed, about this same time a buddy lost a buck hit on the point of the should with the same bullet and lost it, we found it a week or so later bedded near a hole, after finishing it off we found the bullet never made into the chest cavity, so because of the lack of penetration I have abandoned that bullet, Most reloading sources list the 110 to 120 gr bullets at around 3100 fps, however of the at least as seven rifles I've worked with they all produced velocities in excess of 3200 with 3300 not unrealistic with the slower powders, only two had barrels over 24 inch at 25 and 26 inch, multiple chronagraphs have been used over the years so I'm confident there were no false readings, i would be curious as to what other members have found using this cartridge, with most of these rifles I started with the 100 gr bt or the 100 gr solidbase in the earlier days, all but one seemed to have a preference for the nosler bullet, and all but one preferred magnum primers, other powders I would look at besides those mentioned are the slower viht powders starting with n560 165 170 etc, AA magpro, ram shot magnum, imr7828, maybe hogdons retumbo to name a few, sorry for the long response hope this helps