I think your gain would be useable. Heavy bullet, slower powder recipe for success.I thought about starting a new thread to ask but I figure it would work here just as well.
I am going with a fast twist 270 WSM pre-fit Tikka barrel. Was planning on going with a #2 sporter profile vs the current #1 profile. The weight difference is minimal from what the manufacturer says.
My question is pertaining to barrel length.
Would you recommend I stick with the 24” barrel length or go up to 26”?
This rifle will be used for hunting mostly but I would also use it for out to 1000-1200yds for fun.
Would I see a significant gain in the extra 2”?
I know many people who have them in various other calibers and all shoot like your 243. It is one of the reasons I went to Tikka. I know every manufacturer will have defective products. It was the reason I left Remington because the last two rifles I bought were turds.I understand your issue - recently sold Tikka 7mm Rem. Mag as yours. 1.250-1.500" groups with many loads, just none better. Maybe my expectations are too high as I have one in .243 Win. that is about .750" with 75 V-Max and under .500" with 66 Fowler HP match. All 3-shot groups as 4th and 5th will open up with the sporter.
Good luck with caliber choice - almost too many to choose from these days. 270WSM does sound good.