I recently damaged my TKO muzzle brake. Comparing my 2300S without and 2240 with a muzzle brake, it is easy to "hear" when the 2300S is getting low on CO2, not so easy on the hushed 2240. What likely happened is that when the CO2 was low a pellet failed to exit, new cartridge and then next pellet and stuck pellet tumbled around inside the brake and damaged the internals. So be aware and if the slightest doubt safely check for an obstructed barrel.Many thanks to TKO for taking care of it.Nick