Piston Sleeve Guidance
At TbT we aim to bring you the best possible service at the best price. After trials we have decided to supply sleeve instructions rather than a sleeve itself as every gun is different and there is no “One size fits all” solution. PTFE sheet can be bought for this, but with so many thicknesses it’s very hard to get the right one for you. I use either a plastic milk carton or a steel beer can, depending on room available between the spring and piston wall. If you don’t leave enough room the spring will bind on cocking!

Take your sleeve material and cut it approximately 1.5 – 2cm longer than piston body. Wrap the sleeve around the piston and cut where it meets (this gives you a few mm extra but makes it easier to handle). You should now have a rectangle. Roll it into a tube and place inside the piston and mark exactly where it overlaps, do this to both ends. Draw a line to join the 2 marks and cut along this line. Place inside the piston to check it fits (it will be too long at this point). Notches need to be added at one end, these are folded to be held in place by the slip washer, trim the notches so they don’t touch the latch rod (if fitted). Push sleeve into the piston with the join away from the slot (if your piston has one), ensuring there is no overlap and sleeve is fully inserted. Use a craft knife, Stanley knife or scissors to trim off the excess material

Tinbum Tuning accept no responsibility for your rifles legality. After any work check your power levels with a chrono!