German guns, in general, seem more likely to be underbored than overbored, and more likely to be choked tighter than the typical constrictions for the given choke. But the only way to know for sure is to measure with a bore and choke gauge, as indicated above. The "drop-in" type choke gauges only give an accurate reading if the bore in question is standard diameter, or very close to it.
In some cases, the Germans are helpful in telling you how the gun is bored. I had a 20ga Sauer from the 1930's, A&F import, that was significantly overbored. In effect, a 19ga rather than a 20. But that was marked on the barrel flats, so I was not surprised when my bore gauge read close to .630 rather than the 20ga standard .615. And in the case of that gun--and others that are significantly overbored or underbored--the drop in choke gauge will give very misleading readings.
Last edited by L. Brown; 09/05/16 11:00 AM.
