Last week me and Wife/Chic browsed thru the local (good) shops trolling for stocking stuffers for the kids.
Scope covers, patches, predator calls, ammo butt cuffs, cleaning supplies, bore lights, magazine subscriptions, gift certificates. Nice, hand made sandbags are cheap/easy (if you want to add a personal touch) and very useful to anybody that shoots from a bench.
If he reloads there are inexpensive little things that you can't have too many of, like hand made wood case blocks (everbody owns a drill motor: ).
In my take, shooters are the easiest people in the world to shop for.
Shooters go thru a lot of stuff, anything they get gift wise is something they don't have to buy. Cleaning supplies doesn't seem too sexy, but my Son loves it cause he's now stocked up, and he uses them.
J