Asinity: Your grip is the likely culprit. In your post, you mention that you were shooting the Wrangler two handed, the same way as your MK 3. I suspect this is at the heart of your problem.
Shooting single action revolvers is easily mastered. They just require a slightly different mindset from the way we were taught to shoot double action revolvers, or auto-loaders.
Perhaps these tips may be useful:
First: Your Master hand(whether left or right), does the majority of the work, when shooting a single action revolver. As already mentioned, the middle two fingers of the shooting hand form the strongest part of the grip. With thumb wrapping around to maintain hold. The pinky finger should also rest on the grip, as well*. This means positioning the hand a bit higher on the grip to make room. But, not so high as to interfere with hammer function. It takes a bit of practice to get it right, but will feel strong and comfortable, when acquired.
Note: *Positioning the pinky finger under the grip works well when shooting one handed. An aid in cocking. Plus, helps control muzzle flip. But in my experience, offers little to no advantage, with a two handed grip.
Next: Once you`ve established your Master grip...try this test: The trigger finger of your shooting hand should be able to move independently of the rest at all times, while gripping the revolver. You should be able to move the trigger finger freely and easily, in and out of the trigger guard, work the trigger, etc., without altering or relaxing your grip. Once you have a handle on that(takes little time to master) then, move on to establishing ideal trigger finger contact.
There is a tendency for many single action shooters to hook their trigger finger too deep into the trigger guard. Then, jerk or slap at the trigger. Which tends to throw shots off. Instead, concentrate on just the tip (pad of first joint) of the trigger finger making contact. The trigger finger then is in position where all it needs to do is come straight back....easily... to break the shot.
I suspect that another part of the problem is that, you`re not gripping the revolver grip firmly enough with your shooting hand. Since there is very little recoil and muzzle flip with a .22, there is a tendency to hold with a more relaxed grip. This allows the revolver to flop around in the hand during recoil. Which results in inconsistent grip. As a result of which: shots group all over the place.
The cure: Maintain a very firm and consistent grip, while shooting. You don`t need to crush it....but good, hard, steady pressure. A strong grip.
Important: The off hand`s job is to work the hammer. And not much else. In which case, you don`t want to grip as tightly with your off hand, as you might when shooting your Mk 3. Or, like when shooting a double action revolver. This excess pressure will tend to pull the gun`s muzzle downward and either left or right, depending on shooting hand, when cocking the hammer. If your group also tends to print low and left or right, that is a good indicator of too much pressure being exerted by the off hand.
So...your off hand should maintain a fairly light grip. With the palm exerting very light contact. Just enough to stabilize the gun in your hand. But not much more. The shooting hand will always have the most influence on grip.
Also: The thumb should move comfortably and freely while cocking the hammer. When done right, thumb movement should cause minimal gun movement during the cocking stroke.
With many shooters, it helps to place the index finger of the non-shooting hand on the front of the trigger guard. This acts as a pivot point and stabilizer for the thumb when working the hammer.
It takes far longer to explain all this in print, than in actual practice. But, this may be helpful to start.
Al
