257 roberts improved

[calib]

i have a buddy who has one being built and wants to shoot the 75 grain v max any one have any loads or info?

[Slowpoke Slim]

I know I had a load in my standard Roberts. Not sure I made one up for my AI. It will be maybe a week before I can get around well enough to go look (getting old sucks). But I'm using IMR 4350 in most of my AI loads. A general rule of thumb is to start with standard Roberts data and work up. I usually start with a mid range Roberts load when I'm putting a new one together for my AI.

Just an FYI from shooting that bullet in my Roberts, I can tell you it is not fur friendly if he's using it on a pelt rifle.

[calib]

Thanks for the response, was starting to think no one knew anything about this round. He is mainly looking to put some fur down, not too worried about saving it.

[Slowpoke Slim]

I know my standard Roberts load gave me excellent accuracy. I believe that load was made up with IMR 4064, but I won't swear to it. If I haven't popped back on here in a week with it, send me an email to remind me and I'll go out and look. My memory isn't always to be trusted (which is why I write all my loads down in my notebook).

I know my primary load for the AI is a 115 gr Nos BT and a 120 gr Nos Part, as I put it together for a woods Mule Deer gun.

[yobuck]

nostalga reviseted. for the simple reason, WE CAN.

[SFLEFTY]

Like Slim said, anyone who has loaded for a regular Roberts knows something about the AI. It will just take loads above normal max.

[Slowpoke Slim]

Ok, I was able to go out and retrieve my notebook today. I don't have a recipe for the 75 Vmax in the AI. But I do have one for the same bullet in my std Roberts. I used 43.0 grs of IMR 4064. My notes say that 43.5 grs opened up the groups and was borderline too hot.

For the AI, I would recommend 44.5-45.0 grs of same powder with that 75 gr Vmax. This is a max load, so work up to it, once you've fireformed your brass. Use a standard Roberts load to fireform and you'll be fine there.

I'm using IMR 4350 in my deer loads in my AI, 45.5 grs with the 115 gr Nosler BT, and 45.0 grs in the 120 gr Nosler Part.

My daughter's deer load in her std Roberts is 43.5 gr IMR 4350 and a Nosler 100 gr BT. Very accurate load for her and very mild recoil.

I also use the 115 gr Nosler BT in my 257 Wby mag, and accuracy is exceptional. Ultimate pronghorn recipe in my opinion.

[emtrescue6]

I am just starting load development on a brand new build in 257 Roberts AI...(on a Rem 700)...and so far IMR4895 ha proven to provide me the best results with both 85g and 100g Nosler Ballistic tips....both are producing well under MOA results @100 so far. I don't have my book in front of me to share my power volume, but both we're lower than the medium loads as I recall.

[calib]

Good luck with your rifle, my buddy found all kinds of stuff wrong with his custom mauser, for one he put a burnt.out barrel on with a fresh blue job, now we are dealing with welded in screw holes that are rough on top not in line and who knows what else. We got the barrel taken care of and now the screw holes should be done soon, but i dont know if he has the pateients to deal with all that since this has been streyched on a couple years already and in the get go the smith said it was his reloading. Crazy.

[emtrescue6]

Good luck with your rifle, my buddy found all kinds of stuff wrong with his custom mauser, for one he put a burnt.out barrel on with a fresh blue job, now we are dealing with welded in screw holes that are rough on top not in line and who knows what else. We got the barrel taken care of and now the screw holes should be done soon, but i dont know if he has the pateients to deal with all that since this has been streyched on a couple years already and in the get go the smith said it was his reloading. Crazy.

Oh man that sucks! Fortunately for me I have a great smith and completely trust him and he's built me several rifles over the years...plus, I purchased all the parts myself (action, barrel, stock, trigger, etc....) so I know exactly what I have.