I won't go over 130gr. Knight said I can go up to 150gr. At least two techs said so, but one said he wouldn't. You won't be able to get much accuracy over 120gr I found. And velocity spread high. I bought this neat breech plug called powerstem. They used it on the 52. I put a report about it a few weeks ago.

I was thinking I wasted my money but the thing worked great. I was getting over 2100fps and the barrel was so much cleaner than before. The powerstem ignites the powder from the top. Seems to make it much more efficient. I has spreads less than 70fps. I got one group of 2.2" or so at 100 yards with 130gr and one .8" group at 50 yards with 120gr. This was with 250gr barnes expander and a magnum subbase.