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.
 
I don't shoot slugs, but I've had a lot of experience with rifles and ammunition. It's hard to say which is more important, but twist rate and proper bullet-to-bore relationship are both critical. In sizing bullets, I used to try and match the groove diameter of the bore, so the engagement of the bullet was the full difference between land and groove measurements, yielding a good seal of the bore. With high pressure firearms, there is enough bullet obturation for good bore fit if the bullet diameter is very slightly less than groove measurement. With air rifles and slugs, I don't know if that is the case, and I would try and match the groove measurement. I'm sure there are folks with experience in achieving precision accuracy with slugs who have done the work and can answer in greater detail.
 
  • Like
Reactions: Vana2
I don't shoot slugs, but I've had a lot of experience with rifles and ammunition. It's hard to say which is more important, but twist rate and proper bullet-to-bore relationship are both critical. In sizing bullets, I used to try and match the groove diameter of the bore, so the engagement of the bullet was the full difference between land and groove measurements, yielding a good seal of the bore. With high pressure firearms, there is enough bullet obturation for good bore fit if the bullet diameter is very slightly less than groove measurement. With air rifles and slugs, I don't know if that is the case, and I would try and match the groove measurement. I'm sure there are folks with experience in achieving precision accuracy with slugs who have done the work and can answer in greater detail.
Slugs are getting better and better to the point in the case of 22 caliber there is manufacture making up to 42gr high BC boat tails n the heavier n longer.. the more twist is needed, the 1-17.7 is old news for this next gen of slugs..PCP'S are getting powerful and better .. now barrel manufacturer and some pcp maker have to cath up ..