I'm just starting to develop some loads for the the 375 H&H using the Barnes 250 grain TTSX bullet and so I'm comparing data sources and noticed how conservative Hodgdon's website seems to be. I'll start testing with the Reloader 15 powder so hopefully I won't have to try the Varget.


Barnes data - Varget 66.3 - 73.7 grains to get 2,821 fps (250 grain TTSX)
Hodgdon data- Varget 62.0 - 66.5 grains to get 2.642 fps (250 grain SP Generic)


Barnes data - Reloader 15 - 69.0 - 76.7 grains to get 2,863 fps (250 grain TTSX)
Alliant data - Reloader 15 - Max load 76 grains to get 2,847 fps (250 Speer TBBC)

I'm old school and was always taught not to start loading at the maximum charge or to reduce loads below the starting loads listed for slow burning powders, so I don't know where to start with Varget.



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IIRC Barnes say their newer Xbullets, with the bands have less pressure than normal cup-and-core bullets.

That may be the difference.

Frank,
I ran into the same situation except I couldn't get the 250's to group with all of the powders on hand and finally tried IMR4166. Now I had a bullet with no firm data with a powder with no firm data.
Ended up splitting the diff between 235's and 270's and splitting the diff between powders that were close on the relative burn rate chart.
It was a little nerve-wracking but I worked up very carefully and finally found some accuracy.IIRC the final load was closer to what you would expect for the 235's than the 270's.
I never went back and really pushed things with RL-15 (the usual go-to) but maybe would have found a good node with that.

Here is a 100-yard 3-shot group of 250 TTSX .375" using R17 powder in the sister-sized 375 Ruger.
You should drop the load 5 grains because of smaller capacity in the H&H, and maybe work up. The rifle was an over-the-counter Ruger Hawkeye (re-bedded).



That was with a 20" barrel and double-chronographed.

A slower load, but also accurate, with 4451 powder is below, again only a 20" barrel:


You could hunt well with either. Just remember that the above loads are for the 375RUGER, whose case has about a 5 grain larger capacity.

Looks like those two loads are minute of critter fro a long ways,

[QUOTE]Originally posted by Bren7X64:
IIRC Barnes say their newer Xbullets, with the bands have less pressure than normal cup-and-core bullets.

That may be the difference.[/QUOTE


Barnes has said a lot of things over the years, and their position and data change just as often. I remember when they were claiming that you could load larger charges with the TSXs than cup and core bullets.

In practice sometimes I can use the same charges, on average a bit less and in at least two of my rifles the worked up max charge would have been a powder-puff load with a more conventional bullet. The "reduced loads" have all kinds of speed, which does suggest that the pressure was there. No big deal, as long as loads are worked up.