Unlike virtually all other FX products I've owned, this sleeve was an unexpected disappointment. I recently purchased one of the FX carbon fiber sleeves for my 700mm .22 Superior liner. I know it's supposed to be a very close slip fit, but after inserting the liner in the sleeve, it becomes an interference fit after about six inches or so. So much so, in fact, that in order to insert it any further, I would have to resort to using force, and even then, we're talking hammer blows. If one were to peek through the length of said sleeve, one would even find that there are a series of ridges (striations?) that run longitudinally through most of the length of the I.D., though, of course, not the first six inches. I believe this to be the problem. Being a fellow who is more than a little mechanically inclined, I can't really see myself willfully entering into a covenant whereby the force of friction is set upon and overcome through brutish measures. No good can come of it. I have to admit at being a little surprised that FX would have let this out of the factory - it seems so at odds with what I've come to expect from the company. Sadly, I think I'll have to consign this sleeve to the Island of Misfit Toys as it doesn't really seem worth the effort to return it.