Shooting heavy gun better than lighter,

Ok, I am not a new shooter-I just got back into it after Covid. I find my 22 shots not nearly as "decent" as my 45 shots.
The 45 is a heavy Tangfoglio, the 22 is a Ruger 22/45 bull barrel.  Both have red dots.
I can answer the question about weight, as I can hold a 5# dumbbell stock still, so it is easier to shoot the heavier pistol.
The question: is this a permanent curse until my Marvel conversion shows up, or am I ignorant of the proper technique for
shooting lighter pistols?

I would say the majority of accomplished shooters shoot heavier pistols better in general up to a point. I like them about 3-3.25#, balance also matters a lot. Weight helps settle the sights and soaks up some recoil. One exception would be people with joint issues and reduced strength from age. Shoot what you shoot well.

Regardless of weight, grip and trigger control are key. With good technique you can shoot anything well, ergonomics of the gun make it more comfortable to do so.

I found removing 3 oz of weights from the front of my Pardini cut my group size in half.

james r chapman wrote:I found removing 3 oz of weights from the front of my Pardini cut my group size in half.

I find balance is every bit as important if not more important than overall weight. That's a big reason I got rid of my GSP 22/32, I prefer the balance point further back on bullseye pistols, I do shoot a Steyr Evo 10 well but the trigger is light. I put a half dozen or more dot/ring combos on my new 1911/38sp Jon finished till I liked the weight/balance and would cycle with a safe load.

I don't think they are comparable...too many differences. Grip angle, trigger, rotational inertia....

I think the key word is balance, if the gun doesn't balance well in your hand than you won't shoot consistently with it.
I had a range accident last year where my gun box popped open when I was removing it from the bench, the gun tray slid out and my .22 and .45 flipped out landing on the back tube of the Ultra Dot sights which destroyed the sights but saved the guns. I had the old 4dot UD's on both and UD had discontinued them, so I was left to try and find new sights to get the balance reset and have not been successful. 
After talking with Katie at UD I found my scopes could be repaired and I'm waiting for them to return home.
Hopefully they will restore the balance I once had in my guns.

Shoot what you can hold the stillest.