A few years ago I bought a cheapy hex set from M10 and it has been brilliant. Has metric and imperial and all the various shapes. Quality is good despite the price. Julian/WIL sells the same set Gunsmithing &Reloading Tools - 100pc Security Bit Set, Screwdrivers Highly recommended.
Have also bought extra tips (not cheap) for my Fat Wrench from an engineering outfit. Not that easy to find outfits that sell them though. The extra ones you need are the broader ones than the largest in the Fat Wrench set. I now have pretty well covered all my gun screws including grinding down some tips for perfect fit. No more graunched ugly screw heads
I personally wouldn't bother with the electronic version. Have verified my FW against a Warne fixed torque handle. They agree with each other but of course they could be both wrong ha ha. Just remember to always set the wrench to its lowest value when finished with using it.
Bookmarks