Measuring Stevens 520-30 Barrel

[bigskybound]

I know that the barrels on the riot/trench guns were 20" long. I have a beater Monkey Wards version of the 520-30 that I want to make a trench gun out of. Is it 20" from rear of barrel removed from receiver?

[scosgt]

I know that the barrels on the riot/trench guns were 20" long. I have a beater Monkey Wards version of the 520-30 that I want to make a trench gun out of. Is it 20" from rear of barrel removed from receiver?

Barrels are ALWAYS measured from the muzzle to the closed bolt.

[bigskybound]

That makes sense, as I have always measured SxS from back face of barrels, which is essentially the bolt face. As these coach guns are always cut to 20", I never have to worry about running afoul of BATF.