Originally Posted by Tench
I taper ream my barrels so that where the pellet sits when it is positioned by the pellet probe there is no rifling and a perfect skirt to barrel seal, i have found this does tighten the velocity spread.
If you load a pellet into most guns then remove the barrel with that pellet still in situ and look down the barrel you do see light around the pellet through through the rifling lands. this will lead to some air escaping past the pellet as the air pressure rises behind the pellet, this will cause inconsistency, ream it smooth with a reamer of the right dia that tapers down to below the i/d of the rifling lands just far enough to eliminate the rifling at the skirt saves having to size all the pellets and should achieve better results.
Hand reamers have a .25mm taper over the first 10mm of length so are ideal for this.
I knew it, nothing is new
But surely if you can see light through the rifling then you ream down below the depth of the rifling the diameter where the pellet sits is now bigger than the pellet so air escapes around the top?
Now if you did this taper reaming and also flared the skirt of the pellt so it was a snug fit in that taper that would be da'boss