First off, I better get the disclaimer out of the way....

Use this data at your own risk.. I spent lots of time and powder working up to this load. I do not recommend that you try it..

On to the range report.. this is more of an observation post than me sharing my data post.

I recently purchased a Ruger #1 RSI chambered for the lovely .257 Roberts.

A buddy of mine suggested a load of 41.5 of IMR 4350 launching a 117 Sierra BTSP for potent hunting. With his rifle and a 23" barrel, he is getting 2830 FPS and great accuracy. I loaded a few of these up and shot a couple MOA groups with it and was plenty happy until I ruined a good load by running it through the chronograph.

I was only getting 2680ish FPS out of my 20" tube and I was unhappy with how anemic the load was through my rifle.

The only Bob brass available right now is Nosler +p stamped brass, so naturally a purchased a lifetime supply of it. I was showing ZERO pressure signs with 41.5 of IMR 4350 so I decided I was going to step up .5 gr at a time until I started showing pressure signs.

Long story short, it wasn't until 46 gr. Of IMR 4350 and starting to run out of case capacity (just beginning to compress) that the corners of the primers began to start to flatten. I loaded several of each load to make sure the pressure signs were consistent.

The three on the left are 46 gr., the one on the right is 45.5 gr there is also less than .002 of web growth..



This load averages right at 2980 for three shots through my 20" barrel. The data is pretty much printed Ackley Improved Data.



Being a holiday weekend the shooting ranges were way busy so this shooting was done off a very uncomfortable folding picnic table and rest but was still able to get real close to MOA accuracy out of it. As my buddy said, just goes to show how each rifle has its own DNA so to speak.





Thanks for reading and happy shooting!

Todd

Wow...sweet rifle and good information. Thanks for sharing. That would be a rifle on my bucket list!

Is that one of the recent production models Todd? Looks like you are onto something there!

Try 48.5gr of RL26 115gr Nosler Patrition Win cases CCI250 primer Average velocity is 3133fps. Norma
MRP at 48.5gr with 117gr Hornady BT CCI250 Mag primer and 2.850OAL gave 3054fps.

What gun and barrel length is that?

It's a Ruger #1 RSI with a 20" barrel.

Todd

My .257 Roberts is my favorite rifle - a 1989 M77 tanger. Shoots extremely well with a variety of loads. When at the range I have to fight my daughters to use it myself.

With its 22" barrel, WW +P brass, CCI 200 primers:
3609fps, 75g V-MAX, H4895
3233fps, 100g TTSX, H4350
3163fps, 110g AB, H4350
2958fps, 115g TSX, H4831SC
3013fps, 115g TSX, H4350
2947fps, 120g A-Frame, H4831SC

My Ruger .257 has a long throat, as do several of my Rugers. None of the above loads show pressure signs.

I knew that. I got lazy and didn't quote Guntruck50. His velocity is on up there, that's why I wondered about his gun and barrel length

Model 70 pre 64 24" barrel. Shoot same load threw a model 760 Remington pump with 22" barrel at 3008fps. Try a slower burning powder.

Nice write up and thanks for the information Justahunter! I need to get my Roberts out and put a load together for her this summer.

Last year, I had a gunsmith friend of mine who was closing his doors do one last project for me before he said goodbye to his shop, and hello to retirement:

I had an old, Ruger 77 'Tang,' chambered in .270. I had him screw on a stainless Shilen #1, tapered to nearly duplicate the 77RL 'Ultralight' barrel profile, but finished at 22". The barreled action was bedded into a take off 77RL stock, and I fitted a vintage Leupold M8 6x with the plain crosshair recticle on top. I installed a Rifle Basix Sear and adjusted the pull down to just over 2#. The rifle is relatively light, balances well, and just 'feels' good. I found some Winchester +P brass on Gunbroker a while back, I just need to work up a load. Maybe I'll get to it this week after work.

Thanks for the motivational nudge!

RL23 and RL17 give good velocities and are accurate.