I have 2 .410 single shots, a Charter Arms Snake Charmer and a Harrington . The Snake Charmer has a cylndrical barrel, ie not choked while the H&R is choked. I have fired a long colt .45 in the Snake Charmer but the H&R seems to be choked too much to attempt it . I may be wrong. I have the Bond .410/.45 colt derringer and since the barrel is rifled, it is legal to use the .410 shell in a pistol like that.