There won't be that big of a difference between the 8" or 6" barrels. I got 30 to35 shots with my 8" barrel with stock internals. Turn the lip off the inserts ( turn to. 749-.748) and bore the barrel 1.75 deep from the tip of the stock barrel. It only took me maybe 2 minutes to turn the lip off a 9 piece ifit kit after setting size on the 1st one. I had a collet lathe where i used to work that made it really easy to do the inserts. I actually circle milled the barrels on a mazak horizontal mill. That took a minute once i had the program and set up done.