Load Velocity, .257 Roberts

[Argonaut]

Okay, so I have decided to use the Hornady 100 Gr interlock in my .257 Roberts.  Now, I use 47.0 Grains of H4831 Short cut. This load is .5 grains above max in for a 100 gr bullet (flat base game-king).  Velocity is listed as 3000 fps at the muzzle using a savage 110 with a 22 inch barrel.
My Hodgdon manual lists 49.00 grains of H4831 as a max with a velocity of 3010. But Hodgdon uses a 26 inche test barrel and the bullet is a SPR  SPBT

I shoot a Ruger 1b with a 26 inch barrel.  Any one with a chrono ever tested this load in a 26.0 inch barrel? or have  experience with the roughly the same caliber in the two lengths of 22 and 26 inches?
I have always heard that the gain is about 25 fps per 1 inche of barrel.  If this is so then I would expect an honest 3100 FPS from this rifle.  Not that any of this really matters for blacktail hunting at ranges under 200 yards but it would be fun to know.  (I think I will ask for a Crony for Christmas).

[Argonaut]

The first Data Listed Came from the newest Sierra Manual.

[Argonaut]

okay I bought my own chronograph and my results for an average of 10 shots from my .257 roberts using 47.0 grains of H4837SC and Hornady 100 gr interloks shot to an average velocity of 3003 FPS at 10 feet from the muzzle.

[Lone Star]

One of your problems is that you are expecting bullets from different manufacturers to shoot the same.  They do not.  Using Sierra data with Hornady bullets may get you close....or not.  Hodgdon used a Speer bullet for their data. All these bullets have different bearing surface lengths, different core and jacket hardness, and different diameters and lengths.  Each data source used a different barrel with different dimensions.   All these characteristics effect pressures and velocities.

BTW - no need to limit yourself with 70-year-old pressure levels.   Your Ruger can use .257 Roberts +P data, which in Hornady's manual with their 100-grain bullets has a maximm load of 48.3 grains of H4831.  Speer shows a max load of 50.0 grains H4831 with their 100-grain bullet.



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[Argonaut]

I will have to try some of those loads you mentioned but likely after Deer season is over. I hate changing my ammunition right before the season starts.  48.3 grains to 50 grains would likely not cause me any problems in any case because these Ruger number 1's lock up like an artiliary piece, very very strong actions. of course that beings said, it is no reason to be stupid!

[Lone Star]

I will have to try some of those loads you mentioned but likely after Deer season is over.

A wise man indeed!   


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