Shotgun Safety Flag

This is V2.0 of a parametric design for a single barrel shotgun safety flag in sizes from 12 gauge to .410, aimed (ahah) primarily at users of pump action and semi-automatic shotguns but useful for break actions and large calibre rifles.

There is now an improved V3.0 which uses more plastic but is more robust: https://www.printables.com/model/729798

Its main advantage over other designs is that the lug that goes down the barrel is split down the middle. Should a bit of the flag break off, the thin fragment will not cause a bore obstruction and will most likely fall straight through the barrel.

The embossing on the flag can be changed to indicate the intended calibre.

NOTE: Guns vary. If your flag is too loose or slick in the chamber, warm the base of the flag up and gently stretch the two arms apart a bit more.

A .410 safety flag will also conveniently fit the chamber of a .45-70 rifle.