Hi Guys,

I have been reloading .357 for my Marlin for a couple of years now and have developed a load that was fairly accurate.

Recently I decided to try a different bullet shape. I usually use a RNFP but decided to try semi wad cutters for a change. I used the same load as I always have (5.0gns of DO32 and 158gb bullet), and the only things that changed were I had to seat it slightly deeper (although OAL remained the same) and I gave it a touch more crimp, probably less than a 16th of a turn.

Shooting on Sunday I found my groups were awful, they had opened up to several inches. Tried a few of my old loads though (with the RNFP) and they grouped OK. What I'm wondering is why this slightly amended load has gone so wrong, and what I can do to improve it?

Any and all advise, as always, appreciated.