FX Impact inner shroud o ring

[inverted]

Hi!

​I took shroud off FX Impact barrel for cleaning a few times and now I notice that first oring in the shroud (where barrel goes in) is damaged because barrel end just where the thread is, is razor sharp. Does anyone know size of that first oring (one that is between barrel and inner shroud)?

Thank you!

 

[Jack.K]

Mr. Ernest Rowe has a video on how to clean and replace the shroud o-ring here.

http://www.airgunnation.com/topic/fx-impact-teliscoping-shroud-cleaningrepairre-seal-video/