I have no use for one but could not pass up the price. Sako -FN - Likes Remmy 300 Swift A-frames.

What powder to duplicate them. I have RL15, 4350, h-414, ar-comp, Rl17 and a little 4064.

Someone left a target up and I just undotted it :-)

With 300 grain bullets my 375 H&H likes IMR4064 and R15, with lighter bullets it likes R15.

Try all you mentioned; only your rifle knows what it likes...... mine likes 4320 and 4350.

Tried several powders in mine and always come back to RL-15 from 235 to 350gr bullets.

Before I re-chambered to the 375 Weatherby, mine liked Varget, H4350 and 760.
Now, it only likes 760 with 260/300gr pills and H4350 with 270gr. Neither liked RE15.

Cheers.

RL 15 for 270 & 250 grain bullets, and W760 for 300 grain bullets consistently work the best for me, but a few other powders that work well: H4350, RL 19, IMR 4064.

My custom CZ-550 in .375 H&H love this recipe (developed by me):

300gr Swift A-Frame
Federal GM215M primers
76gr RL-17 in Norma or Federal brass, but will work well in other too (RWS for example has a very little lower space inside the case)
COAL 3.48"

The COAL works in way that crimping is not to crimping grove in bullet. I use Forster dies for sizing and seating and Lee factory crimp die for crimping (not sure if crimping is necessary, but I crimp it lightly)

Accuracy and brass life is outstanding so I bought five bottles of RL-17. Also give superb accuracy and consistency in 8mm Mauser.

Jiri