The dimensions other than weight will be the same as a 5" 1911.
- Height (inches) 90° to barrel: 5.25
- Length (inches): 8.7
Reliability, .22 automatics can be finicky creatures and regardless of brand and model you might have to try our several types of ammo to find what the gun really likes. That being said the Umarex guys tend to do a good job. As for the P22, while I don't particularly care for that pistol, mainly due to it's goofy manual of arms as it's a a .22LR the size really doesn't matter and they shoot pretty well.