The Model 12 is famous for a lot of things, but the bolt blow'n open after firing isn't one of them. I've read two of Roy Dunlaps books and don't recall reading about that. Also have read both Madis' and Riffle's Model 12 books, and again, no mention of bolts blowing open.
But, if one or both of the action slide lock springs are broken, a Model 12 can become difficult to lock the action. I had one of my trap guns break one of the springs and I had to turn the gun upside down for it to lock-up. It kept on shoot'n and didn't blow open.
The Model 12 has a safety feature that prevents the bolt from firing if it's not in full battery. If a gun is neglected and abused to the point where it has extreme bolt droop, the gun will not fire. The firing pin retractor is for this purpose. When the action is closed and the bolt is locked up into the lock up notch it presses the firing pin retractor down into the top of the bolt and allows the firing pin to drop.
As Robert said, holding the forearm forward releases the action so the gun will open when the action slide lock is pressed upward. The recoil from firing a shot does the same thing as holding the forearm forward and holding up on the slide lock release, so holding the forearm forward when shooting allows the action to open even easier. Don't confuse this with the bolt blowing open.
The Japanese made Model 12's, do not slam fire like the real ones do.
The 1897 Winchester shares quite a few of these features as well. Release the hammer and move the forearm forward and you'll hear a click, the action will now open.
You'll notice the patent dates on the right rear of the barrel, on pre-1941 Model 12's, share patent dates with the 1897 and the 1893 Winchester pump shotgun.
Here's a photo of one of my 1897's. It's a factory two barrel set from 1901.
You can see where T.C. Johnson got the front half of his Model 1912. They already had it with the 1897 takedown models.
Regards:
Rod
