Several folks have recently asked me about proper gun fit (or fitment) after reading what I wrote in this post and hearing me mention it as a guest on this podcast. As such, I figured it would be a good topic for a post so we can dive a little deeper into the topic.
In the most basic sense, it’s about selecting a gun or customizing a gun so that it properly fits our hand. The operative words here are “properly fit”. It’s not about how good a gun feels in the hand. Rather it’s about how well the gun interfaces with our hand. While I’m not expert on the topic, I know enough to know there are a few nuances that matter some more that others.
Now before we start, note that different firearm platforms interface with the shooter differently. For example, a rifle has four points of contact with the shooter while a pistol has two. In my opinion, which may very well be a bad opinion, rifles are more forgiving than pistols when it comes to fitment. What I mean by that is easier to shoot a poorly fitting rifle well than it is to shoot a poorly fitting pistol well. I think, again perhaps incorrectly, that it’s for this reason that I find myself talking about proper pistol fitment way more often than I do talking about proper rifle fitment. Regardless, I’m going to share what I know about proper pistol fitment in this post and rifle fitment for some other time.
A pistol that fits properly will allow the shooter to establish a good firing grip on it. What constitutes a good firing grip? With a good firing grip, the pad of the index finger should be able to rest centered on the trigger while the pistol remains aligned with the forearm. But that alone doesn’t constitute proper fitment.
Pistol is aligned with forearm 
Pad of index finger resting on the trigger
Here is the first nuance, there should be enough space between the frame and the index finger so that the muscles of the index finger don’t move the pistol as the index finger muscles are flexed while pressing the trigger straight back. This might be a difficult thing to check while at the gun shop for a few reasons. The first is that large retailers tend to place a trigger lock in pistols and will not remove it prior to purchasing the pistol. Another reason is that some gun shops won’t allow one to dry fire the pistol. Yet another reason is because most pistols with replaceable grip components come installed with the medium sized components and one won’t be able to check this with the larger or smaller grip components. For these reasons, if at all possible, I suggest folks shoot their friend’s pistols or rent pistols at the range before purchasing them.
When the gun (or grip) is too large, the shooter is likely to find shots trending towards their non-dominant side (or support side). If it’s too small, shots might trend towards their dominant (firing side). One can train around these fitment issues and learn to shoot well with a pistol that doesn’t shoot properly. However, sooner or later fitment will limit the speed and accuracy potential of the shooter.
Another nuance is the ability to reach the controls on the pistol with as little disturbance to the firing grip as possible. The most important control being the magazine release. While this nuance isn’t critical as the ability to establish a good firing grip and avoid interference from the trigger finger, it can make a fairly significant difference when a magazine change is required during a firing sequence.
Manipulating the magazine release paddle with index finger 
Manipulating the magazine release button with thumb
One school of thought on this topic suggests a magazine reload is an opportunity to adjust the firing grip. Another school of thought suggests a magazine reload is an opportunity to mess up a firing grip. I think there is truth in both. In my mind, the less a firing grip is disturbed during a magazine change has two benefits. The first benefit is a faster magazine change simply because there is less movement required. The second benefit is it minimizes the change of messing up the firing grip during the process. As such, it is my opinion that a gun that disturbs the firing grip less during a magazine change fits better.
So what can a person do if they learn that their pistol doesn’t quite fit them right or could fit better?
Well there are a few options. The most common is to change the grip. Granted not all pistols offer interchangeable grip components. Even so the manufacturer or a qualified gunsmith might be able to offer a grip reduction (where material is removed from the grip).
Another course of action is to change the trigger. There are a plethora of aftermarket triggers available in the market. Several manufacturers also offer different triggers for their pistols. For example, switching out a curved trigger for a flat trigger could help folks who find the gun fits a little small (the opposite applies to folks who find their gun to fit a bit large). This course of action might also require assistance from a gunsmith or the manufacturer.
Should go without saying that altering the grip and changing the trigger are not mutually exclusive. A person can do both. However, it should be noted that finding the optimal combination might require a bit of trial and error.
In some cases where aftermarket and customization options are limited (or nonexistent), a different gun is always another option.
In closing, I’m not suggesting folks immediately go out and try to optimize their gun fit. Rather, I think it’s important to be aware of it and potential improvements so if and when the time comes that gun fit is limiting one’s potential to shoot better something can be done about it. It’s also important to remember that good fitment is not the same as “how good (or natural) the gun feels in hand”. I’m also not saying folks shouldn’t buy guns that feel good in hand but don’t actually fit well. It’s just something to keep in mind and perhaps take into account depending on the primary purpose of the pistol.