Question for Rory. Are the chambers 2 3/4" or 3" and is the barrel loop reinforced? I own #199729 that is a 32" Wild Fowl with all 3 ordnance marks plus V.A. 2116 on the right lock plate but with 2 3/4" chambers and no barrel reinforcing loop. that suggests these early Rochester guns were intended for 3" chambers before the War and were hurriedly diverted into the Rochester program. Regarding the question about US and USA-F 20 gauge, conventional wisdom is that those were war time barrel marks unrelated to the Rochester or military program. My #FW200190 is one of those guns. The only known Rochester 20 gauge is #201424.