I seem to do best with a "moderate" gripping pressure.
I would define "loose" as the way I hold a springer rifle. Someone could easily lift the rifle from my hands without much effort. The pistol would be cradled with this type of hold in a way that would allow the grip to be slid out the top of my hand.
I would define "tight" as a firm grip such as used when shooting a magnum powder burning rifle. If someone tried to pull the pistol from my hands, my arms would be pulled towards them and the pistol would not easily release.
A "moderate" gripping pressure is when my front fingers (especially the second finger) pulls the grip into the web of the hand with a moderate pressure. The palm of my hand doesn't touch or touches very lightly. If someone tried to pull the pistol from my hand, my arms would move a bit before the pistol released. I don't use a death grip.
I'm a right hander. When shooting the HW45, I always use a two hand hold... with the index finger of my left hand supporting under the trigger guard and lightly cupping the other hand (without thumb touching).
I enjoy shooting the .22 HW45. It jumps a bit so I feel like something is happening. I can grab a tin of pellets and start shooting, with no need to check for gas or load a powerlet or pump the tank. Only one stroke is needed to shoot. The 10oz Campbell's cans or 14oz bean cans are an easy target at 20 yards so accuracy is more than satisfactory and the challenge is fun.
With all this said, I also enjoy my Crosman Mk1 pistol and my HW40 SSP. Variety is fun

10M group with SHP pellets
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Velocity with 14.5gr SHP pellets.
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Cans at 20 yards.
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Cheers,
Todd