38 55 smokeless load.

[looseprojectile]

I have this old gun. A #1 Ruger 375 H&H magnum. 24 inch barrel and Magnaported. Groove is .377". Weaver V- 9 scope.
I have been shooting the Lee 270 grain boolit. When I got the mould it was too small and had a bevel base. I fixed all that. I now have a plain base .380 270 grain boolit.
I started with a charge of 24 grains of SR4759. I got some leading. I then reduced the powder to 23 grains. At this level I still got some small flakes of lead.
Shot eight of twelve into one inch, at 100 yards, the other four opened the group to two and an eighth inches. I am going to load my 19 cases with 22 grains and shoot some more. Changing one thing at a time.
I have considered that my alloy might be wrong or that the lube is crap. The lube works fine in 30 caliber guns up to two thousand FPS.
I hope that I can achieve better groups with no leading. This level of accuracy is good enough though I would like to eliminate the leading which may be contributing to the flyers. If 22 grains don't work any better what would you try next? I have not been using a filler and this is a huge case for this small powder charge. I may reduce the charge a grain and add the filler.
Life is good

[Old Ironsights]

38-55 =/= .375...

However, my .38-55 smokeless load is 18gr 2400...

[beagle]

Take a look at castpics: Cast in the .375 H & H. That should give you some ideas. I found that the slower powders tended to give less leading. Now, 4759 isn't that fast but it's pretty fast. One of my better loads was with 4895.

The .375 H & H NUmber 1 is a great cast shooter. We once had a 300 yard berm that burned off one fall. We shot all winter and spring at softball sized rocks on that berm with the .375 and a spotter. For a big case, they're darned accurate./beagle

[BABore]

Try around 38 grains of XMP 5744 and a CCI 250 primer.

[leftiye]

Wabbit medicine!