A little insight, I have purchased 2 Fx CF barrel sleeves, one in .177 the other .25 I shot extensively with both barrels so I had a great baseline for what each barrel was capable of.
Now the good part. Barrel # 1, When I installed the .177 sleeve I epoxied it on (JB weld) without a second thought! Accuracy as good or better especially with heavier pellets or slugs.
Barrel #2 .25 I didn’t use JB this time because of suggestions of other members, so I thought let’s try locktite 242. Bad move, I’ll tell you why, when I proceeded to shoot more groups after installation with this method this barrel shot “not well” so I thought no problem I will put the barrel in the oven and heat it up to brake the bond. this didn’t go as planned! Had a horrible time achieving this but finally able to.
So now a couple lessons and some advice, 1- don’t epoxy first without trying the sleeve not epoxied 2- make sure you know the true accuracy of the barrel without the CF sleeve first.
The final interesting note was after I managed to get the sleeve off it was evident that only about a 1/4 of the sleeve was actually epoxied on and very sporadic distribution. Even with slowly rotating and liberal application.