The rifle I recently built is not yet performing to my expectations. This is the first rifle I have put together myself so I would like to confirm that I am not overlooking something obvious with the basic ‘hardware’ (as opposed to the more esoteric load development aspect). The new rifle uses a new Savage target repeater action, a McGowen 260 Rem 24” SS 1:8 barrel, and a Manners MCS-T5 stock.

The problem: When doing load development my final test for a new load is to shoot 10 shot groups at 300m before taking that load out to the LONG RANGE range (600-1000yds). The basic issue is that the new rifle is shooting 3-4” 10 shot groups at 300m whereas my old LRP (260 Rem) still reliably shoots 2” (or less) 10 shot groups at 300m.

Hardware checks I have performed:

• ‘GO’ gauge chambers fine
• ‘NO GO’ gauge will not chamber
• Barrel nut is torqued properly (Recoil lug and barrel nut are from Northland)
• One piece scope mount is securely fastened to receiver
• Scope rings are securely fastened to scope mount
• Scope is securely mounted to scope rings
• Scope (SWFA 12x SS) came off my LRP which still reliably shoots 1/2 to 2/3 MOA at 300meters
• Barreled action is securely fastened/torqued to the Manners stock

Are there any other potential ‘hardware’ issues I should check for?

I am shooting Sierra MatchKing 142 bullets, Lapua Rem 260 Brass, H-4350 powder, and CCI primers. I have done some load development with the new rifle and it looks like there are ‘good’ nodes around 42.5gr and another around 44.0gr of H-4350. The 44.0gr load was showing some flattening of the primers, but no sticky bolt. I shot 5 shot groups with 42.5 (@2770 FPS) and 44.0 (@2840 FPS) with the chronograph. I decided go with the 42.5gr load for now because it seems to provide the velocity I would like and the brass/barrel should last longer.

If the hardware is put together ok, then could it be just a ‘load’ issue? As in the barrel doesn’t like: SMK 142s? Hodgdon H-4350? Isn’t the SMK142 considered to be fairly reliable across most barrels? H-4350 seems to be the de facto standard for Rem 260 (although it is very hard to find these days).

What should my first steps be to diagnose this problem (hardware and/or load) ?

Thanks for any advice.

Doug