Which current-manufacture rifle configuration would be suitable for a one-armed man? SBR PCC is my guess, but I don't have a ton of experience with a variety of "tactical" rifles.
Strong-side arm use is retained, guy in question is fairly strong and large framed.
I know that’s the idea behind the braces, but I always thought it would be hard/tiring to hold a rifle way out there like shown in the examples above. A fairly lightweight rifle w. A pistol grip, eg an AR or bull pup, pulled tight into the shoulder, can be shot pretty well single handed. Definitely something I’ve practiced for 3-gun and with the 9mm for Uspsa’s PCC division. A good comp would help control recoil. A "pistol" set up with a brace would allow either technique to be used......
So Armbraces and Bullpups...... but... I forgot about the Calico.
It puts the weight of the ammo above and behind the pistolgrip. Some people love them and some hated them. I've had both the 9mm and 22lr versions and they were all a blast to shoot. Nice campfire guns and the kids loved them... and so did the big kids. Pistol or rifle and both 50 and 100 round mags.
an AK with a proper sling would be ideal if strong arm is the right arm, but AK's are not soft shooting rifles and I find them unwieldy when doing one armed drills. An AR with a proper sling could be set up to be ambidextrous putting all of the necessary controls on the right side. The AR can be built or bought very lightweight, and the right muzzle device makes one armed drills pretty easy. I don't think there is any advantage to going pcc over traditional rifle calibers.