I'm glad you finally got around to trying it Jimmy! I told you what to expect and now you can see for yourself. To answer your question about what pellets will do, I will tell you that pellets will do the same thing. There are guys like Richard Utting that "tune" the barrels on their long range rifles using 12 pound "donuts" on their barrels to control the harmonics. The donut dampens the barrel whip inherent with all barrels when a shot is fired...the goal is to tune the barrel so that the bullet leaves at the top most point of the whip.
So you definitely want to keep the liner at the 90 degree position not only because of the tightest group, but also because it is the one most centered with your bore. Now if you want to take it a step further and fine tune your liner setting do two more experiments.
First, using an inch pound torque wrench check to see how tight you made the nut at the muzzle...you may find that making the nut a little more tighter or less tighter tightens up your group even more. But you want to be able to remove your liner and put it back in the rifle with the registration mark at top dead center 12:00 o'clock position, and the exact same torque tightness on the liner/barrel nut. Over tightening the nut or leaving it too loose has a very negative effect on your group size.
Second, now that you have it this good you can loosen the barrel nut and just turn the liner to the right to the 1:00 o'clock position and shoot a group, and then turn the liner to the 11:00 o'clock and shoot a group and see which one of the three groups is the tightest...11:00, 12:00, or 1:00.
Since using a 12 pound barrel weight would not be practical for us airgunners we are only left with indexing the barrel. And as I pointed out a few months ago, barrel indexing is one of the absolutely cool things we can do now that we have this STX barrel system with these liners!
PS: One of the range officers named Pete at the range where I go has a .22 cal. Anschutz rifle that he paid the factory to index the barrel for him...on a flat calm day at 100 yards his rifle will make a nice little 1/2" clover leaf groups that are unbelievable. He is the person that explained it to me several years ago, but until I got my Wildcat .30 a few months ago I could not do it. Until you index the barrel liner on your STX barrel you will never truly know how accurate your FX rifle can be! There are lots of other factors involved in accuracy but I believe this is the foundation upon which all the other things are built. I for one would love to see the results from Bob_O doing this with his .22 Impact using his most acccurate slugs as an example to other guys...it may turn out that his liner is just in the perfect position from Ernest tuning it.
