As i use .22 cal myself, i am sometimes lurking for blog stories about .22´s and just yesterday, or day before that i found this article by American Grouch and i wanted to throw in one of my ideas.
I am not claiming that this would be "invented" by me, or anything, but i havent ever seen anyone mentioning, nor carrying one. You see, i have noticed, that .22 are kind of a pain in the butt for one reason. They are so small, that if you drop a few of them in pockets, they are harder to find by hand, than lets say .308 ammo, or shotgun ammo. They get stuck in seams, and such, almost disappear, and if not, they sure tend to rattle, meaning theyre noisy fellows in loose pockets,especially. There are few .22 ammo boxes, made out of platic, but they are usually way too bulky and have room for big load of ammo,and yes, they rattle too. This, is about ammo boxes ive encountered in Finland, and i donno a thaaaaang about overseas stuff, sorry. You migh be lucky to have better,smaller, quiet ammo holders / boxes, i dont.
Anyways, as i have a variety of old bit holders, for screwdriver bits, those 1/4" ones that you see everywhere, it just occurred me, that the diameters of .22 ammo are pretty much like in quarter inch bits, i took one bit holder, and yes sir, the ammo, went in, and stays there, not too tight to be hard to pull out, but its still super easy to pick up. The holder in my picture, is from Leatherman, it held bits in big combo sheath, meant for Super Tool and its bit adapter back in the days, now its my silent ammo holder, and i dont have to play too much with my fingers in my pockets, trying to find those tiny shells.
Well, this isnt much but just a little something.