Well, I had a good session at the range yesterday testing out some 243 Win, Nosler 95grn B.T./N160 loads.
The powder charges went from 43 to 47 grains in 1 grain steps.
Groups of 3 shots were fired, and to allow the rifle to cool a bit between groups I'd fire 10 shots with my 303 and walk down range and back between groups.
My first group was a "control" group fired using my current load of a 100grn Hornady BTSP bullet over 42grn H4831. All 3 shots snugged into the black of a 10m air pistol target, slightly left of centre, at 100m so I was happy with that.
My first test group printed right at 1" and exhibited 2 touching and one away.
The next group showed 3 shots all touching and I allowed myself to smile broadly.
Out of the 5 groups fired, only 1 exceeded 1.5", but the 44grn load was by far the best. Needless to say, when my current stock of 100grn loads runs out, I already have the replacement load sorted.
The last thing I did was apply two clicks of right windage to the scope and fire a further 3 shot group with the 100grn load into the 10m air pistol target. Job done.