I think I may have misunderstood the premise of your original post, and am certainly way in over my head here. Let me explain:I have not. So Final Finish is a product offered by David Tubbs to fire lap a barrel. It is either offered as 10 loaded rounds or 10 bullets that come impregnated with five gradesof abrasive grit (and is actually VERY fine) that lap the barrel as you shoot. The action takes out tight spots and removes chatter and machining marks as you go. The process is to shoot the 10 rounds of Compound No.1 followed by a through cleaning, repeat with Compound No. 2, etc. I've only made to No.3 but bore scoping has shown results! Having said that I would see what your rifle is capable of. The .338LM needs it but my 6.5CM MSR-10 shoots .3 to .4 MOA groups all day. One other downside (sorta) is that Tubb's only offers the 6.5 rounds in bullet form so you have either roll your own or have someone whip them up for you. David recommends Arizona Ammunition and they can set you up for $89.00+shipping with either the Neco Pressure Lapping system (for REALLY bad barrels) or Tubb's Final Finish kit loaded and ready to rock! I'll post before and after pics of the throat and bore once I finish up. Oh, and none of my business but why solids? My 6.5 LOVES Hornady's 140gr ELD-Ms!
I purchased some self defense rounds for our 9mm and .40 cal, which just happen to be solid copper hollow point rounds made by C.O.P. and H.E.L.O.. I made the assumption that your barrel had accumulated copper bits in or on its surface, that you were unable to remove or smooth out satisfactorily. This got my attention as I'm going to be taking the new ammo I bought to the range to get friendly with it. A friend of mine is a Sergeant and he said he loves solid copper but has to clean his pistol really well after every range visit because it builds up inside the barrel.
Was my initial reply nonsensical or did I misunderstand your post? If so, I apologize for the confusion. I know I'm confused now haha