SHORTEN A RIFLE BARREL
Shortening the .17 HMR barrel will not have an effect on accuracy, as CZ produces its .17 HMR rifles with optional 16in barrels, as do many other manufacturers.
It is a fallacy to believe that shortening a barrel will reduce accuracy.
It will, however, affect velocity to some degree, depending on the calibre and initial velocity.
Typically, shortening a .17 HMR barrel from, say, 22in to 16in will reduce a 17-gr bullet from 2,665fps to 2,551fps, a loss of only 114fps.
The benefit is that you can have a shorter rifle, and the addition of the sound moderator does not increase the overall length of the rifle too much.
The most important factor to remember is that you will need to have the rifle’s barrel expertly reduced in length and then rethreaded to take the moderator.
A failure on this score will create accuracy issues.
Any misalignment, improper damage to the rifling, muzzle crown and thread pitch will cause a dramatic reduction in accuracy.
If you do choose to have the barrel reduced in length, then you will also have to make sure that it is re-proofed.