Home Forums Hunting & Shooting Hunting Rifles 257 Roberts Question

Gang, as for reloading the Roberts, I’m trying to think my way around case capacities, etc. I need some experienced input from y’all.
My current rifle is a SA 700 that’s been reworked. It’s plain old 257 R but it allows for fairly long seating depth to be just off the lands - 2.8125.
With H414/W760 I have unused case capacity when loading to manual specs. I see no reason not to use every bit of that capacity. My 257 AI was identical in every respect except shoulder angle, meaning increased capacity, and you could stuff quite a bit more powder in. Same bullets, brass, primers. Aside from not getting excessive powder compression, is there anything one would need to watch for ? Seems the key would be not to exceed 257 AI max loads which should be impossible given limited case capacity.
Pardon me if this seems a nitwit question but I’d rather ask…..

Are you talking case capacity of H2O?

Is your manual showing standard old Robert's loads or +P?

What weight bullets do you want to use?

100 and 117 gr

Have you thought about reaming it out to AI ???

For 100 grain bullets you can look to 6mm Rem data for matching powders. It's the same case with a smaller neck, so the bigger necked case will digest the same loads at lower pressure. You can work up with a chronograph to 6mm Rem speeds and you'll be in safe territory.

Just stick with loads in the book for a plain .257 Roberts with H4350. If that isn't good enough, try H4831.

Take a look at Nosler's +P load data

I load for the 257 Roberts, but I am not bumping up against its rev limiter. Hopefully Dirtfarmer will be along shortly, he wrings some impressive velocity out of his and tinkers a good bit.

Should outdo the 6mm by a little bit with like weight bullets.

That's what he said.

Thanks for the useful post.

My bad. I thought he said work to 6mm velocities, not above.

Mule Deer (John Barsness) has excellent and useful 257 Rob data, and I've found it to be spot-on in various Rob's.

Here's a google search engine you can use to find his posts on the subject:

https://cse.google.com/cse?cx=016407629494559605640:xponie3lspc

As always, work up to these loads.



Ruger #1 26”

Nosler 100 NPT. 46.5gn H-4350, W.W. Super 160-164gn case, Fed 210m primer, 2.880 COAL. 3200fps + or – from 26” #1


Load data 257 Roberts Ruger 20”, Savage AXIS 24”

Nosler 115 NBT, 45gn Hybrid 100V, WW +P or RP 173gn case, Fed 210m primer, 2.885 COAL. 3100fps + or - from 24” AXIS II, 3050fps from 20” Hawkeye.

I have used Mule Deer’s load of 47.0 gr or Ramshot Hunter with Fed 210 primer and 100 gr TTSX with excellent accuracy and velocity. If you are needing way more than the 3,000 fps this load produces, I suggest a .257 Weatherby Magnum.

.257 Roberts Loads

Warning! Notes: Source: Handloader Issue #247 - June, 2007

Be Alert: Publisher cannot be responsible for errors in published load data.

Wt.........Bullet.............Powder Manufacturer....... Powder Charge.......Velocity (FPS)
100... Nosler Partition......Hodgdon H-4350..................48.0 ..................3,157

Remarks: 100-yard three-shot groups (inches): .78

As I noted above. Work up to this load. For me at sea level, it was 46.5 of H-4350 from a Ruger No.1B with a 26" barrel. Velocity 3,200fps.

As always, work up.............

.257 Roberts Reloading Data (Using Hornady Bullets)

Warning! Notes: This data was shot by Brian Pearce, Wolfe Publishing Company. Gun: Ruger Model 77R; barrel length: 22 inches; case: Winchester +P; primer: Winchester Large Rifle; bullet diameter: .257"; bullets: 100 GR SP, maximum COAL: 2.780"; maximum case length: 2.233"; trim to length: 2.223".


257 Roberts Load Data
Using Hornady reloading data with the 257 Roberts bullets

Be Alert: Publisher cannot be responsible for errors in published load data.

Wt............Bullet.........Powder Manufacturer.........Powder Charge........ Velocity (FPS)
100...... Hornady SP.........Hodgdon H-414...................46.7.....................3147

Remarks: maximum load

the ladies and grand kids are all now using 257 Robert rifles ,just easier for all to have same cartridge and the 257 Roberts is a very fine cartridge i feel. i went to using Reloader 17 powder and 75 gr. Hammer Hunter bullets work good on game are accurate too with decent velocity and low recoil . enjoy your new to you rifle,Pete53

Thanks for all the good info. Ima look at Mule Deer’s load data today. The reason I’ve been using H414 instead if 4350 is that I have a bit of a supply of 414. I’m keeping the 4350 for my -06 needs. Only shop around is charging $70 a pound.