Personally I would think of 1mm as still cutting it too fine. I would feel more comfortable with two mm or more. Some times you can actually see the barrel flexing if you stand behind the shooter. Slipping a £10 note between the barrel and the woodwork might be alright for something like a .22 BSA Martini international but not for something with a bit of poke.Dennisgrm wrote:Barrel/Stock clearance is recommended at a minimum of 1mm for use with a sound moderator. Especially with a factory 'plastic' stock. These stocks are very flexible and change characteristics in different temperatures.
https://www.youtube.com/watch?v=AqgPu9gSmVc