My first double (actually the first shotgun I personally owned) was a J Stevens Arms & Tool Co gun. Do not remember the exact model now but was a low end, either 325 or 335. This gun had the simple cross wedge bolt engaging a slot in the rib extension. Bought it about 52 yrd ago. I had not started reloading so shot ordinary factory loads, mostly 3-1 1/8 but a few 3 3/4-1¼ & when the new mags came out (max-1½) I even bought a box of them & tried them. Barrels were steel, though unmarked as to maker. In my youth I thought as they weren't those "Deadly" Damascus I could use whatever I desired as long as was 2 3/4" 12ga. Don't really know what the chamber length was. Anyway when I eventually traded it off it seemed none the worse for wear. Sure wish I had it back now, for sentimental reasons. This was a cocking rod gun with a cigar box frame shape, very similar to the "Innovative Action" of a certain makers M21. Totally unlike the later 311 type guns.