FAL308,
Thanks for the feedback on this gun's operational obscurity. This was a matter of curiosity as I know it's Remington cousin, the Model 11, had seen military service in the hands of the shipboard MAs and their SP counterparts. I'll contact you via email regarding my own endeavors on this particular gun, but for the sake of our casual forum readers I'll herein render what little information I know of the gun.
The Winchester 1911SL (self loading) shotgun was the original John Moses Browning automatic shotgun design.
Its operating mechanism is the now classic Browning short-recoil cycle. Firing recoil initiates a rearward movement of the locked barrel/bolt unit. The barrel/bolt assembly is slowed by the barrel lug compressing a recoil-spring and the binding effect of a friction washer assembly that surrounds the magazine tube, then the barrel lug impacts a stop on the receiver face, the barrel’s rearward movement stops abruptly, the bolt unlocks, disengages from the barrel extension, then momentum carries the bolt on its rearward movement, extracting and ejecting the spent case, all the while being continuously slowed by a bolt recoil spring mounted in the butt-stock. The barrel recoil spring returns the barrel and its extension to battery, and a bolt recoil spring initiates the forward movement of the bolt and the elevation of new cartridge inline to the breech axis. The recoil spring continues the forward movement of the bolt and cartridge to their respective lock-up positions at the barrel extension and breech.
This model is unique in that it is actuated by grasping a knurled portion of the barrel, behind the front sight and compressing the barrel down into the receiver to duplicate its short-recoil firing cycle. There is no bolt handle as is standard on almost all subsequent auto shotgun designs. The sear and disconnector arrangement of the Winchester 1911SL is almost identical to that of the 1911 Colt pistol, which he had also designed. Additionally, all of the metal component parts including the receiver and barrel extension are milled from forged steel billets, a prohibitively costly process in this day and time.
The 1911 SL in its original condition suffers from a barrel recoil spring that soon weakens and causes the barrel to batter at its stop. An obvious symptom of the spring fatigue is the fore-stock splitting from the repeated shock. The butt-stock is of a tri-laminate design that also doesn't withstand field use well, and eventually separates. The bolt recoil spring guide is essentially a metal capped wooden dowel, that is prone to swelling, softening and eventually breaking within the milled-out center layer of the butt-stock, usually resulting in a binding of the bolt recoil spring and rendering the firearm useless except as a club (remember, no bolt handle to assist the bolt back into battery with the barrel breech).
JM Browning had a serious disagreement with Winchester over this firearm, and as a result severed all relations with them. He took the design to Herstal, Belgium, for its production under license by Fabrique Nationale des Armes (FN) as the now famous Browning Automatic Shotgun (this version added a bolt handle and dropped the knurling on the barrel, but otherwise it was the same action), which in its recently discontinued configuration was called an Auto-5. His new arrangement with FN was sufficiently satisfactory to him, such that after his death they continued the development and production of his last brainchild, the now ubiquitous Browning Hi-Power.
