I have an Rossi single shot rifle in 357 maximum with 20" barrel.All load info i have is for 14" and 10" contender barrels.Would i have better luck with slower powders using 180 grain bullets.The 180 gr bullets shot a scattered group with some keyholes.The twist is 1-14" like the rest of my 35 cal.guns.It will shot a 1" group at 75 yards using 158gr bullets.
thanks

I shoot cast bullets out of single shot topper in 357 max. I can shoot bullets up to 250 grs with decent accuracy. I use the same loads in a T/C with a 14" barrel with no problems. I use mainly 2400 and IMR4227 once in a while. I haven't shot many jacketed bullets out of mine. I use 160 gr and up bullets.

Mark i think the twist is too slow its 1 in 18".I cant get any bullet over 158 gr to stabilize.
jacket or cast.....
thanks

Wheelgun101,
The powders of choice are H110 and WW296. I have had good groups with 180 grain bullets in barrel lengths from 10 to 24 and twist rates from 18 to 10. Revolver, contender and HIGHLY modified SKS - no problems in any of them.

PaulS