I was out yesterday with a friend doing our monthly plinking session with cap-and-ball revolvers. This time, I took my old Armi San Marco Walker clone. I had traded for it maybe 25 years previously and it is one of those guns that is as much a gunsmithing project as a shooter. I have a few of these "betes noires" in the safe and every now and then I drag one of them out, attend to their latest woes and complaints, and go "Waltzing Matilda" with them to see what else they will do to to aggravate me. Just stubborn, I guess. The last operation was gluing in the arbor with JB Weld to correct a tendency to loosen on firing from the rather coarse threads and lack of "meat" at the rear of the frame.
It had done well with ~30-grain charges the last time out; the arbor had remained tight. This time I changed out the spout for one closer to 50 grains, to see how the arbor would handle the extra strain. (Shooting wimp loads in a Walker is not satisfying; it's like running errands in a Nitro-Burning Funny Car.) The gun was performing very well, regularly popping all our accumulated water-filled household throwaways, except for one particularly defiant and invulnerable coffee can, which appeared to have the power to deflect round balls under, over and to the sides.
I had fired at least 40 shots, and the cylinder was beginning to turn rather stickily. I popped out the wedge and daubed some Bore Butter on the arbor, which, to my delight, was still tight in the frame. Reassembly showed the cylinder turned as easily as at the beginning of the session, which is really noteworthy. On my other revolvers, using much smaller charges, the arbors must be wiped with a wet cloth and relubed after 60 shots max, and the disassembly and relubing will need to be done again after another three or four cylinders. Eventually, the disassembly and wiping becomes more frequent than the shooting in between, and it's time for lunch.
This time, the Walker had had no misfires, was shedding busted caps out the cutout in the side of the recoil shield--neither sticking on the nipples nor falling down into the lockwork (my friend's 1851 Navy is a particular offender that way) and though the loading lever now loosened after a cylinder full of these heavy loads, it didn't fall far enough to tie up the gun. Ramming was getting harder; the chambers were a little rough, and perhaps the fouling was accumulating in there. Some of the balls needed a second ram as they were rising from air compression in the chambers while others were being loaded. I swabbed Bore Butter on top of the round balls, and was using Navy Arms RWS #11 caps, pinched slightly before insertion so they didn't fall off. Hey, all right, I thought; maybe the old clunk is finally starting to work like it should.
Another couple cylinders did their devastation on the milk cartons and plastic bottles. The cylinder was still turning fine. Time for another try at the coffee can. I loaded, greased and capped the cylinder and pointed the gun at the target. Have at you, Sir, I thought, and pulled the trigger. There was a tremendous, ragged roar, like that of a Volley Gun, and the target was obscured by smoke. "Hey, was that a Chain Fire?" Steve asked.
Yes it was, the Mother of all Chain Fires. I had experienced a couple or three in the past, generally confined to the next load to the right of the barrel; once or twice the one adjacent to that also went off. This one was the entire cylinderful, and, exasperatingly, none of the shots had hit the coffee can. I gingerly peeked sideways at the chambers, seeing they were all empty, and noted the cylinder still seemed to rotate OK. I rotated the cylinder, flicking the caps off the nipples. They had all cooked off; except for the lack of priming compound, they looked unfired. The bottom chamber had driven the ball against the rammer, but the lever was still up. I pulled it down, and, with some effort, pushed the ball out of the rammer slot. The ram still slid normally, and none of the screws seemed bent. Elmer Keith's experience that the rammer had been upset in the slot and had to be driven out and turned down to work again hadn't happened to me. The barrel was still wedged in the arbor; nothing was loose.
I cocked the gun, pulled the trigger while holding the hammer and letting it down gradually. It looked like the gun still functioned, although the outside was all over black powder fouling and grey lead smears. Well, time for lunch. We packed up all the shot-up and undamaged targets, including the ironclad coffee can, and drove to the restaurant.
When I got home, I took the revolver completely apart and cleaned it. The arbor was still tight. (Thanx and a wave of the Bent Ramrod to whoever gave me the JB Weld idea; that is Good Stuff!) All the parts came out, looked normal, and the reassembled, cleaned and lubed gun seems to function normally. The cylinder has (and had) no endshake, but the cleaned chambers still look rough. I think I'll polish them out and go to 0.454" balls next time; the .452" balls were obviously none too tight and maybe the roughness of the chambers, the looseness of the balls in the chambers and the much larger powder charges had allowed the flame to get in the front and set the cylinder off.
The saving grace of revolvers is that the assembly is out in front of you and any mishap will likely project forward and vertical. No magazine under one's hand or slide to come back at one's face. Still, nothing to be complacent about; at a regular pistol range, with shooters shoulder-to-shoulder, there might be serious consequences. But I'm kind of gratified at the way the old Armi San Marco took the abuse. The Walker is too massive to even recoil hard under the chain-fire, although the recoil was noticeable, for sure. It'll be going out again in the future, with some lessons learned.