Getting back to guns, easily included in that discussion is holsters.
What actually do you carry your spare handheld in?
Here's a recent addition for my hunter that has growled at coyotes more than a couple times.
I have the premium (longer-more body protection) version XL size for the hunter. He takes his herding thing seriously.
So what's my point?
Here's the matching weapon holster
Of course it attaches. Or just get the pack attachments. Both available in Coyote grey. Having the hunter arrive with a spare, or a couple handfuls of cartridges is kind of neat.
Last, of course the harness is available in small for those of very small stature who try to brag about whatnot.