Osteoarthritis here as well, both knees (very bad), both hips (bad and worsening), left shoulder (along with a damaged rotator cup) and my left thumb!.
Diclofenac (mainly Ibuprofen) for 5 years, Naproxin for 3 months (gave me severe leg cramping at night), stupidly large amounts of Tramadol topped off with Paracetamol for the last 7 years, all it does is take some of the sharp edge off the pain, if I take enough to significantly reduce the pain I'm unable to drive or shoot.
Taking Diclofenac or any Ibuprofen (Brufen) based medication you should really take an antacid such as Lanzoprazole, as Les said above it can have serious effects on your gut, a sure sign is if you get any acid reflux.
Most of my shooting is indoors sitting, the odd monthly prone outdoor range date (or in a fox hole if I can get in/out!) sees me knackered after about 1-2Hrs and by the time we get home I'm not able to go anywhere for the next couple of days
Apart from that, just keep smiling and taking the tablets

things could be a lot worse! :lol:
Edited as I need to get this off my chest, sorry
For me things are looking a lot worse, been at my GPs twice this week about my recent test results (not good at all). I went this morning and when your GP starts a conversation off with "Well, I'm giving you 3 months" it tends to make you sit up and pay attention rather quickly!. Luckily he meant 3 months to improve my recent results, not going into details in case my kids read this but if things don't improve I'm looking at some unpleasant surgery and major changes to my lifestyle (didn't know I had one!) and medication that would probably mean I would have to give up driving and shooting.
Got two specialist clinics appointments next week to go through the various options. No idea where this is going to end up but hopefully it won't be the worse alternatives.