Scirocco II's in .300 Win Mag

I've been working up loads in 180gr Scirocco II's for my .300 Win Mag. To put it bluntly, this has been by far the worst loading experience I've had. The groups vary from bad to really bad. Powders in various weights used so far are RL19, RL22 and IMR4350. Anybody have a recommendation, I'm about to give up on these.

Meanwhile my first 3 rounds of 180gr Accubonds using RL19 shot just under an inch so I'm quite certain there's no issue with the rifle or scope.

Strange its not doing better. My limited experience with the first Scirocco bullets was pretty good. Your powder choices are good. Assume you are using a magnum primer. Your gun just may not like them, it happens. But before you give up entirely, try some H4831. I have found it to produce stellar accuracy in several guns when others wont do it. Velocity may be less as its pretty slow but always adequate. The burn rate charts always show R22 being slower but it isnt, not by a long shot.

Normally the RL22 has shown to be good in the Tikka shooting 200gr A-Frames and 200gr NP's with excellent accuracy. What I mostly need to do is leave well enough alone, those two rounds will work well on anything in Africa short of DG. But noooo, I have to keep tinkering....

I've been giving the H4831 some consideration, I've never used it before, but once again it's popping up on the radar screen with your comments on it.