Some people have 'tarted' the look of their S4*0's by sleeving it in carbon fibre tube though. 12mm inside diameter. You will need to fit a new barrel band capable of taking the 14mm O/D of the tube. Rowan do them. Depends whether it's for form or function.
Edit. Has anyone here done this and if so did it stiffen the barrel up?
S410C .177 Regged - MTC Viper 4-16 x 50
S410K .177 Regged - Hawke Nite-Eye 4-16 x 50 AO IR
S410K .22 - Hawke Sport HD 3-9 x 50 AO IR
Logun Mk1 .22 - AGS 3-9 x 40
Theoben Taunus .22 - Simmons 4-12 x 40 AO
Webley Premier .22