Last year I got a new 257 Roberts built by John Lewis. M700 la, Lilja .257 #2 3 grove 1:10 twist 24"bbl, Brown Precision Pounder & a German Zeiss 3x9.

Got it Masters week & for various reasons didn't get to try it until the week before deer season. It shot 1/2" with 117 Sierra flat bases & 45.0 gr of h4350, the only load I tried. Killed several does with it but since we have big hogs on the farm this year I developed loads using partations. Since I'm happy with 2,750-2,800 fps I did not bother getting the chrono out, wish I had bothered now.

115 Partation with 48.0gr of rl22 average of 3 groups .42

115 Partations with 43.0 gr of h4350 average of 3 groups .20

120 Partations with 43.0 gr of h4350 average of 3 groups .37

This is the most accurate rifle that I own. I have 200 or so 115 partations but each full box is a different lot, 150 120gr all in the same lot. Slightly under 1# of rl22 & 3.5# of h4350 in the same lot. I have about 80 virgin Winchester brasses, 70 once fired from the same purchase & 42 cases with the 117 sierra load. I think I'm going to shoot up enough shells to get 150 once fired brasses. Then load up the 120 partations & h4350. Since I'm 62 150 rounds should last the rest of my life.

This should prove that a 1:10 twist will stabalize a 120gr .257 bullet.

Looks like you have shooter! My Ruger Ultralight doesn't shoot anywhere near that!
Peter.

No, no, no. I'm afraid you've made a terrible mistake. It's a well known fact that .257 Roberts will simply 'bounce off' anything larger than a jack rabbit or ground hog. You should sell that rifle to me and buy yourself a rifle in a more effective cartridge. :P

What overall length are you seating these rounds? There is a lot of debate on long vs std length robert's rounds. I have rifle, but only been shooting factory ammo, and have not started handloading for the Bob yet.

csam, I don't know who you are addressing, but I am seating them out as long as they fit in the magazine. I see no use for a magazine fed single shot!
Peter.

If you've got some time on your hands try a dose of IMR 4064 with the 117 grain Sierra's.
35 grains works really well with my Remington Classic. Not the hottest load out there but I haven't tried souping this up as it shoots great and most of our shots out here on the West coast are under 200 yards anyway.

I load the Lewis to 2.544 to the ogive, a wood stocked custom to 2.599 to the ogive but my classic actioned rifle is only good for 2.444 to the ogive. If you are shooting a Mountain Rifle the 1 I had the magazine was .2" too short for the throat.

If you PM me you can come out & shoot with me.

Wow,
thats a great shootin rifle.
if you chrony your loads please let us know what you find out.
I have shot a lot of 120 grain aprtitions from my RL Ruger and its a super acurate load with 42, grains of IMR-4350 and even my 20 inch tube gives 2720 FPS.
I loaded up some with IMR-4831 hoping to get another 80 fps or so out of her...tj3006

tom ga hunter

That's excellent accuracy!
I bought a new Ruger 77 Mk II in 257 Roberts last October just before our Deer season and didn't have any time to work up a load. So, I loaded up some 100 Grain Nosler partitions with 45 grains of H-4350. The load shot three shots into a 9/16" group at 100 yards, so I called that good enough for hunting here in our swamps. I think the H-4350 in the 257 Roberts is about as good as it gets for accuracy. John Barsness who writes for Wolf Publications advocates H-4350 for the 257 Roberts also.

Hey guys,
I am a Roberts nut. I have 2 roberts rifles now and a Roberts AI being built .
If you want to try somthing that works really well , for me, get a box of 100 grain barnes tripple shocks and load them over 46, grains of H-414. It get about .75 form a featherweight ruger , and and velocity is about 3140, from a 20 inch tube. I have got the same velocity and acuracy with a 100 grain balistic tip.
Tom, are you shooting 3 or 5 shot groups in that custom ?
...tj3006

Agreed. My best results (accuracy wise) are with Barnes TSX 115 gr. bullets. I am still looking for a cheaper solution!
Peter.