While I agree swabbing between shots on a range when testing sabots or other projectiles is a good idea to keep all things standard, like Triple Se7en I also like to shoot under hunting situations to make sure the rifle will take care of any problem I might encounter, such as a fast second shot.
Today I was shooting my Green Mountain Barrel in Stainless Steel. A .50 caliber with 1-28 twist. I plan on shooting it during out muzzleloader season, when scopes are not allowed. So I was trying some new maxiballs out of it with open sights. I was only shooting 75 grains of Goex 2f, but never swabbed the barrel for seven shots. I just like to see that it will hit over and over in the same area.
It finally threw the seventh shot a little. I went in, swabbed the barrel, put up another target and it was right back on the money... That also is important.
I am lucky. I experience no hard crud ring in any of my rifles. At least nothing that a simple swabbing will not remove. Also there is no projectile that I shoot that I could not load on average three or more without a swab. If I had to swab every shot, it would be a target range projectile only, never a hunting load.