The pattern given by rifled bores at HD distances compared to smooth bores is more in line with mosts expectations for defensive shotgun uses.
If you spin a shot charge, you ARE going to the "donut hole" in the center of the pattern. How big it is, is going to depend mostly on the distance from the muzzle. How important that is, depends on your target, the distance, and how well you aim.
There are so many sabot slug products that get accuracy similar to that reported from the .410 pistols shooting 45lc.
Small point of order, here...
You cannot, should not, and MUST NOT fire .45 bullets through a
.410 pistol"!!!!!!
Despite the common usage putting the number "410" first these guns are NOT .410s they are .45s!!! They have .45 caliber bores!!! Call them .45Colt/.410 and you are correct, using the American standard of putting ACTUAL bore size first, and additional information second.
Most often seen in wildcats, such as the .357/44 or 6.5/.300 Weatherby, and in some factory standard rifle rounds, such as the .30-40 Krag, .30-06, and 7mm-08. Actual bore size first, powder charge, or parent case, or other info second. The British use the exact opposite system, naming the parent case first, and the actual bore size second, such as the .577/450. (.45 caliber based on the .577 case)
And, lets be clear about something else, in these .45/410 pistols, you are firing a .410 shell down a rifled .45 caliber bore. Using shot, or sabot slugs, or standard slugs, you do NOT have a large bearing surface in contact with the rifling. SO, the shot, or slug is NOT spun as effectively as would be the case in a rifled bore of the proper size for the shotshell. You do get some spin, enough to make the donut hole with shot, and give a slug some spin, but not as much in .45/.410 as you would in a rifled 12ga shooting 12ga shells.
My experience shooting .45 Colt in guns also chambered to fire the .410 is that they are NOT as accurate as firing .45 Colt in a .45 Colt only barrel. They may be accurate enough for you, if all you need is minute of man at 15feet. They may even do a bit better than that. Mine didn't, and I wound up getting a .45 Colt (only) barrel for my .45/410 Contender. And, yes, it shot .45 Colt more accurately than the combo barrel.
Recoil might be a bit much with a 12 or 20, but a 28 might not be so bad.
Everyone has a differing definition of "not so bad".
What do you think about a larger gauge shotgun pistol?
The main drawback to a shotgun pistol (aside from the legal issues) is simply SIZE, followed by capacity. Bigger shells, bigger gun, no getting around that, period. Bigger shells means less capacity in a manageable size package, as well.
Imagine the bulk of a 12ga revolver...and if you can get past that, you still have to contend with capacity. A lot of people feel two rounds (double barrel) or even 5 or 6 (revolver) simply isn't enough. Note how many 9mm advocates don't argue the .45 doesn't work, they argue how the 9mm works and holds more rounds...
You simply are not going to get more rounds in a shotgun pistol without going to something much, much larger than common handguns.
And, forget about semi auto shotgun pistols with detachable magazines. Not going to be legal in any place with an AWB law. (which requires the semi auto pistol have the mag in the grip or be an "assault weapon")
SO, if you want 4, 5, or more rounds, you are stuck with some cut down version of a pump or semi auto shotgun, and that is covered under fed law, if smoothbore, and much larger and less wieldly than regular handguns, if rifled.
Could serve well enough as a nightstand gun, an "in home" home defense gun, but would be a crappy choice for a carry gun.
Now, the smallest shotgun gauges (above .410) would have the same drawbacks as a 12ga, though in lesser degree. Also they would be less effective, as well. More effective (with suitable loads) than a .410, BUT, to what degree??
Would it be enough to make them a commercially viable product?? Perhaps, though it hasn't happened yet, and shows no signs of doing so, at this time.\
