With ammo it likes your 22/45 should be mechanically capable of 1" groups at 25yds. Getting your sight picture, down, trigger control and being consistent with those shot to shot should get your offhand groups down to 2" at 25 yds and likely quicker than you think. Clay pigeons on the 50 yd berm should be your goal, and no reason you can't get there.
The dry fire practice not only re-enforces proper sight picture and trigger break, it will strengthen your trigger finger and ability to hold the gun steady. Most people don't think of shooting a handgun as physically demanding, but if you're not shooting regularly your muscles aren't used to performing those tasks and you need to build up those muscles.
One thing not touched on is the ability to analyze what is causing your groups to be poor. You should know exactly where the gun is pointed at the time the gun fires. This takes a surprising amount of concentration but is critical. You should be able to tell if you missed to the right because either the gun was pointed to the right when you fired, or that your trigger pull moved the gun to the right. If you're shooting low you should be able to tell the shot went low because that's where the gun was pointed, or that you pulled it low due to a flinch.
I developed a handgun flinch years ago when I was young and foolish and figured if I'd planned to shoot a box of ammo or two through my 44 mag during my shooting session, by golly I was going to burn through that box even if I started flinching at 30 rounds. One of the worst things you can do, and I've been fighting that flinch off and on ever since. Lots of quality dry firing is a surefire cure, and helps your accuracy.
