Gunsmithing Tikka question...

i just reread what I typed and it's clear as mud. What I meant to ask was since all T3's are long actions, do they need to be modified when using longer bullets in SA calibers like 6mm CM sat out long. I know remington 700s need to have the feed ramps trimmed up to clear the longer rounds.
 
I don't see why they would. The bolt throw length is governed by two different bolt stops, and the magazines are reduced by a spacer in the rear of the magazine. If you wanted to use a .223 with really long bullets or your 6mm cm with long bullets, just use a long magazine and a long bolt stop. If you try and load long with short bolt stop and short magazines then yes you would have lots of problems.
 
The AI mag will be the limiting factor to how far out you can seat the bullets. CDI makes the AI compatible bottom metal for the Tikka, but I only know of the 308 mags sized. To do what you are asking, you will have to go back to the std Tikka BM and mags. If there is an aftermarket, long cartridge/bm combo, I have not seen it.