I was wondering if anyone has replaced the outer barrel with a CF tube of approx 14x8? (for a .22 cal) That should be stiffer and lighter than using a thinner CF tube sandwiched between the liner and outer barrel sleeve. I realise there would be some mucking around required to install the transfer port etc. If the liner is glued then I would presume it would not need to be compressed by the muzzle jam nut.