Thank you for the advice @dnl42 and @Mike. I should have said it's not the main colour but how to spray the camouflage lines/pattern on the barrel but as mentioned above, I suppose a cocktail stick (or similar) would help to hold while I rotate to get the desired lines or pattern effect. In the picture the lighter colour is the base colour which was applied as per above suggestions, and the darker green is my attempt to spray the camo lines/pattern. I'll have another go at it thank you