If your gun is like many today, it comes with a variety of backstraps and maybe other grip parts in the box. How do you decide which configuration to choose?
For me, there are 3 or 4 aspects to fitting a gun to my hand. The first is trigger reach. I want to grip the gun comfortably in the middle of my hand and be able to put the pad of my trigger finger across the width of the trigger. This is not a specific measurement, it is a feel thing. By “middle of my hand”, I mean that the gun should not be twisted towards the outside of my wrist, nor inwards towards the first knuckle of my thumb. Aligned with my forearm is not a bad reference point. This is usually adjusted by adding or subtracting the appropriate backstrap, but for guns that have adjustable palm swells, the right side palm swell (for a right handed shooter) may need changing as well.
The second issue is support hand placement. I want enough room on the left side of the grip (again, for a right handed shooter) to allow a good portion of my control hand to gain traction. At least the drumstick should be on the panel, maybe a bit more. This gives me better recoil control than if the panel does not have enough room for my control hand. A good example is the Glock 43X family. Feels pretty good in a one handed grip, but has way too little support side panel for my control hand to have optimal control. The backstrap is still the most likely way to adjust this on most pistols but if you can adjust the palm swell, a larger palm swell on the left side can give you some much needed room sometimes.
The third issue, which is kind of tied to the second issue in some ways, is that assuming I can fit the gun to allow for the first and second issue, I also need to have a really good grip on the gun. Not in the shooting sense but in the “I don’t want to drop the gun” sense. If the grip is too big, it can be harder to retain the gun during various activities, so I want issues one and two to also allow me to “feel” like I’m securely gripping the gun. This isn’t usually much of an issue, but has been on a few pistols.
The fourth and final issue for me is that after all this fitting, I don’t want my grip to interfere with the controls. Again, this isn’t usually much of an issue, but it sometimes pops up. When I grip the gun, I do not want to be able to touch any of the controls from my master grip, except for the thumb safety if there is one. If the grip adjustments put me too close to the mag release or slide release, I have to be extra careful not to hit them while shooting.
This may not be a scientific approach to the issue, but it is the order of importance for me and is how I go about fitting the gun. A small amount of trial and error with these adjustments is all it takes, and most of that can be done dry fire. Once you have it where you think it should be dry, take it to the range and run it through its paces as hard and as fast as you can. That should smoke out any issues that you may not have been able to identify in dry fire.
