Barrel Porting

[ScrapMetal]

The first couple of things that come to mind are a loss of bullet velocity and accuracy. If the ammo is well matched to the barrel the gases will still be expanding at that point and for the last six inches. Cutting ports back on the barrel will have the same effect on velocity as cutting the barrel shorter. Where accuracy is concerned I would be worried that the escaping gases will cause the barrel to "jump" downward while the bullet is still in the barrel and then have an affect on where the bullet goes.

JMHO and theory,

-Ron