You need 50 repair to make 'weapon repair kits'. You can level repair to 30 easily then with 'comprehension' and a 'fixing things' book you can make a big pile of weapon repair kits at a very early level. If you buy the ingredients for 'weapon repair kits' it's about 20 caps each. You can find them easily enough too.
Jury rigging needs level 14 and 90 repair. Comprehension is available at level 4 and 50 repair is easy to achieve. You can play most of the game with your weapons in fine shape long before jury rigging is available. It's also not worth it, for me, to throw away the even the 20 points, assuming 'fixing things' use just to fix my armor. It's pretty easy to make lots of bucks and I can use the points elsewhere.
In the hand loader perk perhaps, I've never used it. Stuff seems to die alright, I'm pretty tactical anyway.
While I prefer using jury rigging (I like high repair for various reasons and by the time it gets up there there's little else I need to push higher so I may as well grab jury rigging for ease) this is viable. My first hardcoe playthrough was the first I started using recipes properly and Novac is a beautiful place for weapon repair kits, even without tagging repair I was at 30 with comprehension when I reached it, got enough stuff for about 14 kits and then just used the magazine and made a load of kits.
Unfortunately, I never actually used them, so currently they're being held by EDE
But yeah, it is a very sound tactic, I don't use hand loader either and if you don't care for repair generally (checks, traps and repairing) then just getting it to 30 with comprehension should work really well.