In my considered opinion, this is a fairly broad array of weapons to discuss, with each bearing assets and liabilities.
For starters, the single action revolver…A person with a decent single action is far from unarmed. The popular calibers for SA revolvers such as .357 Mag, .44 Mag, .45 Colt are all very capable rounds in most configurations. That being said, I really think the single action is a poor choice in the vast majority of cases.
"Well they worked purty good fer Wild Bill Hickok!" Back in those days, Wild Bill Hickok did not carry a flintlock pistol for nostalgia. He carried the best gun that then modern production standards could provide. All the nostalgia and romance aside, I'm sure most or our legends and heroes would have chosen a Glock of some iteration if they had the choice.
And yes…the SASS guys…yup. Very impressive, indeed. My issue being that they are all shooting extremely light loads at some pretty large targets. If those guns start firing full power loads, a person persons options become much narrower when faced with the choice whether they want to have rapid follow up shots or control their weapon. Also, while I understand the intensity of competition, there is a far cry of difference from competition to the ugly experience of fending off a lethal attack. In a home invasion scenario, you may have flashlights to hold, doors to manipulate, or you may need your off hand to push back the psycho charging at you with a large screw driver. I myself have carried single actions for CCW. It was a Freedom Arms Model 97 in .45 Colt. In a pancake holster. I loved that gun and hated being apart from it, but in retrospect, I had a heckuva case of cognitive dissonance to justify that weapon choice.
At another point, I had decided to carry a hot loaded .357 Blackhawk in bear country. My family and I found a beautiful berry patch and started picking. We were unaware there was a grizzly bear nearby who had already claimed that patch and took great umbrage to our trespass. Consequently, I found myself talking very softly and kindly to a very annoyed bear. My family was retreating behind me, and I had that single action drawn with hands shaking like a leaf in a windstorm. The bear kindly let us retreat, so thankfully I received a gentle lesson about weapon choice that day. I will concede that caliber choice was stupid, but the choice of a single action was far stupider. While bears and thugs are most definitively two different critters, I'm pretty sure the adrenaline dump is similar, and if I had needed that revolver I already had the odds stacked against myself. If things had been pressed farther and the day saved, it would have been through luck, not skill and forethought.
Speaking of shaky hands and jangled nerves, let's say you have identified what appears to be an immediate threat, the revolver has been drawn, cocked, and in accordance with the findings of Dr. Enoka, your finger is off the trigger like a good boy or girl. The threat turns out to be the family cat knocking something off the table, the teenage kid sneaking in, or perhaps even some meth monkey that immediately submits. Great. Now you have to un-cock that gun. Easy, right? When you've just had a massive adrenaline dump, people are yelling or moving all around you, and maybe it's zero dark hundred, or you've been off work with a head cold…Yes, I know we all understand firearms safety, but we are also people who make mistakes, especially in stressful situations. I question whether it's truly a wise idea to uncock that revolver under such circumstances, whether or not you fall asleep every night repeating that mantra to "Never let your muzzle cover anything you are not willing to destroy." Speaking of the findings or Dr. Enoka's study, we can also consider postural instability and overflow effect as factors to consider with a cocked gun and a short, light trigger stroke.
I love a single action revolver for hunting or plinking. Self protection…not so much. If that's all a fella has, I would rather encourage them to rock the heck out of it than feel some…weapon inferiority, but for the price of a SA revolver, I think there are generally better options available in boring polymer autos or a double action revolver.
On the shotgun I'm a bit warmer to the concept. While there are advantages to internal and external hammers to be debated, I actually am not one to minimize it's potential based on the old limited capacity argument. It's a very short, lightweight weapon that is easily managed under stress. Exposed hammers do have the same liabilities as the forementioned SA revolver. When qualifying with the pump shotgun I became quite adept at port loads, select slug drills, shooting from various strong hand and weak hand positions, etc., which was cool…I guess….? I found myself with a room full of unamused instructors however when I asked if anyone could cite a single incident in which the day was saved with a select slug drill, port load, etc. The silence was a bit awkward…Oops. It did however serve to reinforce my personal belief that the prescription of one or two rounds of buckshot under most any incident I'm likely to encounter as a private citizen or a public sector employee is not likely a physically complicated matter. The clicking of a safety forward or the cocking of a hammer is quite simplistic. I like that.
There is a book entitled "Halloway's Raiders" which is a fascinating read. In summary, cops hid in freezers and backrooms from the late sixties until the late seventies….early eighties and more or less blasted the hell out of people threatening and robbing convenience stores. The shotgun was the requisite weapon for this duty. I will become a liar if I try to cite exact numbers here, but I can recall that it was very rare to require more than two rounds from a shotgun to stop an attacker.
Now for me personally, I choose an 870. If I ever use it for protection, I think it good that I have trained on it, and I certify with it regularly. But I certainly would never begrudge the choice of a decent SxS shotgun, as long as that choice is made objectively and thoughtfully.
Lever actions have some previously mentioned shortcomings, but I still find them to be very acceptable for personal protection. The cocked hammer and aborted shot thing…yes, it's certainly something to be cognizant of. The potential to short stroke is quite real. I never experienced it myself…until a few days ago when I was showing off and trying to impress my wife. To me it's a more dedicated platform, but like any of the weapons mentioned, can be learned with practice. I have had jams with them plenty of times before. As in the cartridge jumping the gate and rendering the weapon inoperable. I've also had brass stick in the chamber, and I know whose fault that was, since I'm the weapon cleaner and the ammo reloader. They also don't seem to operate particularly well from awkward or sideways positions. Simply put, I have and utilize better options for a protection rifle, but I just can't quit loving my lever guns, therefore I accept the liabilities, try to work around them and grin from ear to ear every time I shoot them.
I realize I'm not entirely objective in my considerations. I'm much harsher towards the SA revolver than the lever action rifle, though objectively they share many similarities. I strive for objectivity, but at the end of the day, I'm just as subjective as anyone else on this medium.
I apologize for being long winded and full of pontification. I just found the topic a bit more profound once considered beyond first blush, and figured my thoughts and opinions demand at least a brief explanation to hold the possibility of noteworthiness.