What are you going to use this rifle for? Plinking, truck gun, suppressed, unsuppressed?
24" would be my vote- the weight won't hurt and neither will a little bit of added velocity, especially if you're setting it up to be a LR gun. I don't even know if I'd replace the stock TBH.
I went with the new Rem 783 Heavy Barrel-- 6.5cm, 24". I can get a Boyds stock and DBM and still be a few hundred under where you are at with a CTR before adding an McM. But the 783s I've had before any additions have all shot incredibly well.
All that said-- the Tikkas are a helluva gun. I think my decision would be driven by my aftermarket stock options. I know there are differences between the CTR bottom metal and normal Tikka bottom metal. You'll need to decide what BM and mags you will run and in what stock before you pick either model.
Question I have a Tikka T3X in 308 with a brake I find too load. Which is better cut and crown the 20" barrel or use a thread protector? Just a deer rifle for the bush.Mostly plinking also be a lr deer/sheep gun for the wife. Probably won't throw a can on it just a brake.
ThanksA thread protector would do nicely. You may need to check your zero or fine tune your load after changing things. The difference can be surprising. I'm not familiar with the thread pitch you have but you can measure it and purchase accordingly. I had my T3 30-06 Hunter muzzle threaded to 9/16x24 for a custom brake and suppressor since there was not enough barrel to go 5/8x24.