Actually, you said he can't rack the slide on "most semi-autos."
The Glock is one of the easiest to rack.
In my own experience, the folks that had real strength issues also had a weak trigger finger. Now, if he can pull a long, hard trigger thru the DA pull, then you might've solved the problem, presuming he can solve HIS problem in 6-8 shots or less.
If your Dad might have trouble depressing a relatively light springed button on the Beretta 86, then I'd have to doubt he'd have the strength to pull a DA trigger all the way thru. Evenso, could he quickly reload a revolver if necessary?
If the only real concern is racking the slide, then perhaps someone could rack it for him in advance. Keep a few loaded mags around and he should be set.
Another option is a .22 semi-auto. The hard part here would be loading the magazines, but you could do that for him in advance.
But is this concern for a defensive gun one that he brought up to you, or one that
you think exists? The answer would make a difference in how you proceed.
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