I have a Valmet in 9.3x74r that shoots great with 55 gr of 4064 over a 286gr bullet. I have 3 boxes of Speer 270gr hot core. I have tried 58 gr of 4064 with the 270's and the top barrel shoots high, but the bottom barrel is right on. Are these loads too fast? Please advise.

Thanks

DPM, I think you should standardize your bullet weight in order to "regulate" your double. I have a Tikka 512SD in 9.3x74R. Basically the same gun. There are a variety of bullets available but they won't all group well unless you adjust the velocities by handloading. If you really want, you can adjust the POI of the lower barrel by adjusting it.
Peter.

Peter

Thanks for the tip. I will crony my 270gr load tomorrow and see if i can match the velocity to my 286 gr load, if not I'll just by 285's

Thanks again

Once you decide on a load, your Valmet is very easy to regulate with the built in adjustments. I've done lot's of them, and it just takes a bit of time to get them where you want them.

DM

Hello, DPM:
I understand you are trying to make the two bullet weights regulate the same, without fiddling with the regulating adjustments. In pure theory, with the 270 grain bullets, your Valmet is "shooting apart". According to theory, your load is a little bit slow.
But before you rise the charge, I think you should verify with the chrono your speed and powder load are below the recommended max!
Maybe your Valmet does not like too much Speer bullets. You could try another bullet brand of the same weight. In any case, the money invested in three boxes of bullets is not worth risking your rifle or something worse.

Antonio

Double rifles shoot different to single barrel rifles in that you want both barrels hitting point of aim at 100 or 150 meters win a 3 inch composite group with 3 shots from each barrel shot alternatively. Graham Wright book shows that you do not increase powder charge for lighter bullets. Often the same charge will regulate the lighter load. Increased charges will definitely change point of impact.

This is what I found out on Sunday. My loading data says 58gr of 4064 with 270 gr bullet=2300 fps. I started with 55 gr of 4064 and worked up using my crony. 56 gr of 4064 gave me 2300 fps, and the gun shoots great. I'm a little suprised the reloading book is that far off.

Thanks again for all the help