Tuning Fast twist barrels and slug tuning

Hello,


Is the reason why slugs are more challenging to tune related more to the inadequacy of common barrel manufactures twist rate or poor interference fit between bore diameter and bullet bearing surface?

Looking at ordering a barrel for optimizing high BC 22cal slugs.


Thank you in advance
It used to be more of an issue with heavier ammo, not so much anymore. The 1:16 twist works very well with a lot of the .22, .25, and .30.

177 would benefit greatly from 1:15 or less for slugs at 16gr and heavier
 
The only problem in the case of .22 caliber that 1-16 are only aviable in the FX .. RTI MORA .. and now the Scout that has a 1-15.5 .. in one of the last MAT D . Vid the fx 1-14 clearly out shoot the other 2 with the 1-16 .. even when that impact he said is has a bit harmonics because of the 800mm barrel .. So in my case I be here waiting until some eastern European guns manufacture decide to use a proper 1-14 twist unchoke 16mm thick 800mm long barrel in a bullpub configuration .. for my next pcp until then i be here looking and waiting.