But shotguns are bad for accuracy since most of the shots will not hit the enemy unless you're right up next to them. Unsure whether overkill shots count or just go through, but judging for my horrible accuracy when i use the Hydra (and no, I don't snipe with it or anything like that), I would say they don't.
Use rifles, magnums, pistols for accuracy. If you're good, machine guns can be good too on harder difficulties if you aim for the legs since they wont' kill and enemies will fall into your line of fire.
Shooting barrels hurts your accuracy. I don't think medals, jewels affect it though. --- "I expected disappointment. In that regard, I was not disappointed." Official Husband of Gregor of the FE:A boards.
I'll use Magnums over Shotguns since the L Hawk has good recoil AND fire fasts if your obsessed with accuracy. Sometimes you might accidentally miss with a Shotgun if your not careful, but that might just be a problem with me since I use it for crowd control.
If your not using Infinite Ammo then the SIG Handgun is a fair replacement.
I think shooting gems doesn't lower the accuracy, not sure if it raises it though or the BSAA Emblems. --- Repeat Infinitum. If you don't get the above post, just assume I'm being sarcastic.