Originally Posted by Dragline45
A revolver is a different story as it is unsafe to have your thumbs that close to the cylinder gap.
This is a common internet half-truth I always feel compelled to comment on for balance.
While it may be true that gasses from magnum-powered ammo can injure your thumb if it's too close to the gap, it doesn't automatically mean that your thumb will
be injured no matter what
you're shooting. In fact, a thumbs-forward revolver grip is
an option if
you're shooting standard-powered (i.e. non-magnum) ammo. Many competitive revolver shooters use a thumbs-forward grip (with no adverse effects) because of the control it gives. Just remember to curl your thumb down with the hotter stuff.