In the U.S. both J. Stevens Arms & Tool Co. and N.R. Davis & Sons used the mono-bloc style barrel construction.

From J. Stevens Arms & Tool Co. General Catalogue No. 52, which some say equates to 1906 --



By J. Stevens Arms & Tool Co. General Catalogue No. 52 (Revised Edition) they had gone to the demi-bloc method. This from their 1912 Shotguns catalogue.