No, I don't remember. However, a tiny amount of digging reveals that USN barrels typically have grooves of 0.5-1% of the calibre, so an 8" barrel (the largest naval calibre in widespread land service) would have grooves of up to 2.03mm. That's 0.058mm in 1/35. I'm not sure I could see that, given that it is around half the diameter of a (thick) human hair. I'm given to understand that it is technically possible however, although I imagine that the barrel would need to be printed vertically and you still have the issue of ridging on the exterior to overcome at the post production stage, so question whether it is worthwhile.