Does anyone out there have and +P load data for the 257 Roberts featuring Winchestser 760 powder? I checked out their website and they only list one load and it is for a 75 grain bullet. I have been given an 8 lbs. canister of this powder and would like to use it in my 257 with 100-120 gr. bullets. Any help will be greatly appreciated.

Quote from the Hornady manual: CAUTION: this data is for +P pressures in +P cases.

the following are MAX loads.....beware!!!

75 grain bullet.....win 760....49.1 grains...3,500'/sec
87 grain bullets....Win 760...47.1 grains...3,300'/sec
100 grain bullets..win 760...44.2 grains...3,100'/sec
117 grain bullets..win 760...42.4 grains...2,800'/sec

Speer # 13, W760
87 gr max load 47.0=3163
100 gr max load 45.0=3113
120 gr max load 43.0=2770

Hornady
75 gr max load 45.4=3300
87 gr max load 45.6=3200
100 gr max load 43.7=3000
117 gr max load 40.1=2700
120 gr max load 40.4=2700

Nosler
115 gr max load 40.0=2809

I'll add that the Hornady data I posted above is from the single caliber load book, so probably not the most recent.

In my nosler book there is little if no mention about the +p but their loads are comparable to the hornady loadings mentioned above. I think the original +p issue was established a long time ago and that it doent really come into play with modern rifles chambered for the roberts.

IMO the original Remington rifles chambered for the .257 Roberts (the 722 and 725) are strong enough for +p loads as is the Ruger and M-70 rifles afterward. The problem was that there was a lot of small ring mausers chambered for the Roberts prior to Remington making it a commercial cartridge. Because of this Remington (and others) loaded it to abouit 45,000 PSI. Far under the cartridges potential in a M-98 or other commercial action of it's day.

I had remembered reading pretty much exactly what you wrote vapodog, but couldn't exactly remember the details...I have been doing a little homework on the roberts, kinda interested in getting one.

My load is 41.8 gr of H380, WW case, Federal LRM primer pushing a 100 gr pspcl, at 100 yds 5 shot group looks like 1 hole 1/2" in diameter with an occasional flyer. This is the average with this load, not the exception. Barely perceived recoil makes it an all day shooter as well.

What gun is it chambered in?????

Would you believe a Remington 700 ADL synthetic. I'm not the only one getting accuracy like that out of the synthetic ADL, JamesB has also posted about the one he has. I believe he was shooting Federal factory partition loads and the Barnes X.