Any way, the barrels are now mine.Brought them home and tried them on a 12 ga. Skeet.Sloppy fit. However, I have lots of bolts and could fit them. Then tried them on a flat side 1943 which has 30 and 28 barrels(factory letter) and they fit. A little tight.Next, off to the range with slugs for groups at 25,50, and 100. If all works out, I will have a M-21 double rifle. 12 ga of course.