I reported the other day on the results of the first range trip with the new 257 Roberts. The group was just a tad under 7/8 inch with the federal Premium shells loaded with 120 grain Partitions. I came home and loaded a box of 115 grain Nosler ballistic tips. I loaded 43.5 grains of IMR 4831. Today I chronographed the Federal factory loads today as well They read 2674 average with onlt two fps spread in velocity. 3 shots. I next checked my hand loads which read 2649 average for five shots with a 31 fps exterme velocity spread. My OCL is 2.820. This is because the magazine box is pretty short and won,t allow me to set them out any farther I am way the heck off the rifling with that seating depth. The group with this load however was .390 center to center. Once again the wind was about 27 mph but not as gusty as the first day I was out. When I shoot a group for a hunting rifle, I shoot three shots as fast as I can get back on target. When I shoot a group for a varmit rifle I shoot five shots taking time to not let the barrel heat up. To my way of thinking that is a common sense approach to testing a rifle for its intended purpose. If its a new load I fire a three shot group and let the gun cool and repeat this for a tolal of three , three shot groups. This gun and scope seems to repeat the groups like a photo finish. I am Happy with every thing except the velocity. By looking at the brass, It looks like I can bump the load up by 1 1/2 grains and try again I would like to get to about 2700 or 2750. I have yet to try a 100 grain bullet which should give me more velocity but the 115 grain Ballistic tip will give me the same or better final trajectory than the 100 grain unless I could gain 300 fps or so. I won,t be unhappy with the velocity I am getting now with a gun capable of hitting a deer in the eye at 150 yards or better.

My Hornady handbook shows a max of IMR 4350 and 42.0 grains.

Supposedly in a 24" barrel that yields 2,800 FPS.

I was loading IMR 4831. My Hornady book shows a max of 44.8 grains. I loaded a few more to try next time at the range. This time I went 44.5 Grains and a Magnum primer. I only have a 22 inch barrel which I hate. I woul like to see at least a 24 in barrel if not 26. Its a hell of a lot easier to bob off a barrel than to add on. In the old days I would have sent it in and had it rebarreled with a 26 inch barrel. Nowadays I will leave it alone and if I think I need more velocity I will get a 25-06. That would be more fun anyway. I could go Ackley improved and maybe gain a little but not much with that short barrel. I would be pretty happy to get about 2750. This was the first load I have tried so I have a lot of things yet to try. Tonight I loaded a few 100 grain Barnes X bullets. From the Barnes Manual I loaded 46 grains of H414. One grain under max. WW Magnum rifle primers. Of course thier data was also worked up with a 24 inch barrel. My next thing to try would be a faster burning powder.

my 2.57' s really like Hornady 75gr moly hp' s, sitting on top of 47.8 gr of H380 in a winchester case and WLR primers. Should prove deadly for ground hogs. Sits right under 3500 fps. 2/3" grps. Haven' t tried any reloads for hunting season though I still have some Hornady Custom, 120 gr btsp, that averages 1" grps. IMR 4350 looks to be promising in deer weight bullets.

For what it' s worth, the " Nosler Reloading Guide Number 4" states for 100 gr., 115 gr., and 120 gr. bullets, the most accurate powder tested is IMR-4350. Good luck.

I may try 4350 as well. I have some of that. I have a case of Accurate MRP which loads the same as AA 3100. That may be a little slow for the Roberts but I have a bunch of it. It works good in 243 and 270 rifles as well. I think I have all of the current reloading manuals. I may try the swift 120 grain semi spitzer as well because of the short magazine box. I quess I could get the box altered to accept a little longer OCL.