1916 Dwm 7.65

[A.Mifsin]

Originally posted by Ron Wood
A 7.65mm barrel on a 1916 is not original. You can replace the 7.65mm barrel with one in 9mm without any problem. You may have to replace the mainspring also if it was changed when the 7.65mm barrel was installed.

Thank You Ron, am understanding you correctly,you can change from 7.65 to 9 mm but you can't from 9 mm to 7.65mm. Is it because of the chamber, since the 7.65mm is a bottlneck round? Could it be that this gun was modified during the Weimar Era because of the Treaty of Versailes Pistol Restricions ?
Alf