300 wsm next step

[Abolt]

Well i started reloading a little over a year ago and had great results with my abolt 270. it is shooting sub .25" 100 yds groups almost every time but never more than .5". however I have a Browning A-bolt medallian left hand in 300 WSM that is giving me fits. I typed all of my load data into excel and will post. I dont care how heavy the bullet is but I would like to stay above 3100 fps or else there is no benefit over my .270 Can some one look at the data and see what you would try next? thanks

 

[Gunpoor]

A friend of mine has a left hand A-bolt in 300WSM and his load for it is

Winchester brass
66 grains IMR4350
165 grain Hornady SST bullet (seated .010" off lands

I helped him develop this load as it is the same load I shot in my Tikka T3 300WSM. Both of thise rifles wore about 23" barrels.
The Tikka would shoot them into .5" at 100yds while his Browning shot them into .75" or a little less. These were both new rifles and he shot his more than I shot mine but eventually his rifle broke in and shot .25" while mine stayed at .5". The more rounds he put through that rifle the tighter his groups got. BTW, this load seemed pretty much max for us and both guns ran right at 3000ft/sec. My youngest son, who is 1500 miles away from me, now has the Tikka so I don't know if it broke in to better accuracy or not.
Btw, we tried slower powders with these bullets and the loads went straight south for us.