I've killed a bunch of deer with various 257 Roberts chambered rifles over the last 50 years. I'd actually have to look but suspect it's approaching 100 or so. That does not include sheep, caribou, numerous antelope and my first 11 elk and untold smaller critters..

I started hunting big game at age 12 with a sporterized Mauser 98 with a Douglas barrel in 257 Roberts and shot it exclusively till I left for the service.

If you have access to Ken Waters Pet loads check them out and the section of the book on the Bob. It is one of if not the most definitive write ups of the 257 Roberts anywhere. He mentions that for him the 257 Roberts tends to shoot 100s more accurately than heavier bullets and of course they can be driven a bit faster. My data would tend to support that thesis. Whether the tiny increase in accuracy and speed is worth the lower ballistic coefficient and carry would be the issue only you can decide.

Yes, any modern rifle in 257 Roberts should be able to take at least the same pressures generated with a 6mm Remington. The down fall of the 257 Roberts to the various 6mms ala 243, 244 and the 6mm Rem was because the 257 was severly under loaded by manufacturers to accomodate older rifles, mostly pre war stuff.

They also were viewed by writers as a better dual purpose rifle than the 25s, which is a myth.

Back to bullets and loads. The 257 Roberts works best with powders in the medium burn rate catagory. I use IMR4064, IMR4320, IMR4350 and even IMR4831 when I use heavier bullets in the 115 to 120 range.

There are some pretty standard loads for the Bob that get you 3000 -3100 fps with a 100 grain bullet that work well on deer, even big deer.

When you get to the 115s and various 120s velocities will drop off with a reasonable loads at 2800+ fps. I have never been able to achieve 3000 fps with the Bob using 120s with any of the 38 rifles I own that are chambered in 257 Roberts, without excess pressure. It can be done with the 257 Ackley Improved but for the average guy it isn't worth the time, efforst or cost. If you NEED 3000+ fps out of a 25 caliber rifle using 120s it's best to just get a 25-06.

These loads are specific to individual rifles I own. Most are warm but not excessive. I would drop at least 10% as starting loads and work back up if you used any of them..

120 grain Nosler Partition with 45.0 grains of IMR 4831and a CCI200 primer at 2821 fps with a SD of 12 fps. I've also used 117 Sierras, 120 Grand Slams and even some Bergers and Swift A Frames in this weight. Some rifles like different bullets.

120 Nosler Solid Base with 42.0 grains of IMR 4350 and a CCI200 primer for 2805 fps with a SD of 11 fps. This is the single most accurate HEAVY bullet load in my rifles chambered in 257 Roberts plus the 8 or 9 owned by brothers, cousins and other family members. (I do everybodies reloading and load work)

100 grain Nosler Ballistic Tip or Partition with 46.0 grains of IMR 4350 with and a CCI200 primer gives 3087 fps with a SD of 9 fps and is the "Standard deer load" in the family when using the 257 Roberts.

85 Grain Noslers and 87 grain Sierras will work IF they are a hunting bullet and not a varmint bullet. Be sure and check the box and the manufactures data on the bullet. They can be driven faster than 100s but the BC is lower and they shed velocity faster so I tend not to use them hnting big game any more.

The single most accurate load I have found to date in the 257 Roberts was designed around a custom Ruger #1 with a 28" Shilen Match Grade barrel chambered with a tight neck that requires turning brass but when I do my part I have managed 5 shot groups as tight as .313.
That load is a 75 grain Sierra HP with 42.0 grains of IMR4064 and a CCIBR2 primer for a velocity of 3387 and a SD of 6 fps. That is essentually a bench rest load and when fired in the #1 I weight sort all the bullets and brass the other standard brass preperation, uniform primer pockets, chamfer and uniform flash holes, chamfer case mouths and anything else I think of. I know not needed in a hunting load but I have LOTS of time.

However, in my Standard Ruger #1 and various other Winchesters and Remingtons it has also accounted for a **** load of rockchucks and coyotes over the years.

If you handload then you could start with any powder with a medium to slightly slow powder and work into the bullet. If you use +P cases be sure and reduce the load data to start as they hold less pwoder and pressures can climb real fast all of a sudden. Load slightly off the lands if you can.

Some rifles chambered for the 257 Roberts don't allow for this. Some manufacterers chamber it on their short action and set it up for the SAAMI spec of 2.75 OAL in the magazine and then chamber the rifle with a long throat. Just incase you decide to use 120 round nosed bullets I guess.. The Winchester Model 70 and the Browning A Bolt are terrible when it comes to this. My Featherweight needs to have stuff loaded to .273 in order to work through the magazine correctly. Sadly it is chambered with a long throat and the bullet takes a .367 jump when fired. That's not conducive to the best accuracy.

Rifles chambered on the standard/long action allow a longer AOL and allow seating much closer to the lands. The Ruger 77, Remington 700s and Sakos were/are chambered on the standard length action along with a bunch of others. Savage 99s must be loaded to 2.75 to work in the magazine regardless of the chamber.

In the family enough guys hunt with various Rugers and Remingtons in 257 Roberts that we finally took them all in one winter and had 19 of them all throated to take a 120 Nosler loaded to 3.00 AOL and be just off the lands. It seems to work fine for everybody and then it doesn't matter who grabs whos box of ammo.

If it ever cools down I've have a bunch of load work done with the seriously slow powders and 120s to fire for groups and chronograph to see if they work better than IMR4831. Those include Retumbo, IMR 7828 and H1000. If it actually pans out I'll post the data.

The 257 Roberts is a great cartridge and you should enjoy the heck out of loading for and hunting with one.

Ross W Thomas
Great Basin Ranch
Owyhee County, ID