Spacecoast;
You are thinking too much
If your hold is a little off at 25, then it will be way off at 50.
Next time you go out to practice, I would like you to slow fire at 25.
Do not attempt 50 yds.
If you can clean a 25 yd target slow fire, then go out to 50.
Just a little hint.
If you cannot do it at 25, you sure as heck will not do it at 50.
As far as the trigger goes, you said that it surprises you.
No, the gun going off should NOT surprise you(that leads to a flinch).
You should dry fire enough to know your gun to the point that YOU know when it will fire.
Someone told me this once and I believe it is true.
"90% of shooting disciplines is mental, the other 10% is mental"
Think about it
Clarence