I know that shooting while moving is not great... I have a character being chased by another and shooting at each other so they're both running. The chased character uses a handgun and misses wildly from less than 60 feet away. That sounds normal enough, but I'm wondering if it would be weird if the character is a sniper that hits targets 1.5 miles away with rifles? Maybe I should give them other handicaps too - i.e. drunk, no glasses, shooting offhand??
So, a couple things here. So I'll just separate them out.
You probably get this first part, but I'll spell it out, just in case it's someones' first time. The basic idea of aiming a firearm is that you're working with a very small object (the bullet), and you want it on a very specific trajectory. While the specific physics are different, you can experience this (without a weapon) by playing with a flashlight. As you move around, the light's going to bounce around a bit. You can specifically slow your movements so that you're keeping the light trained on a specific point while moving, but you sacrifice speed to do that. The same thing works for firearms. You can keep a stable aim while moving, but, you're sacrificing mobility for it.
The weird part about the sniper is the 1.5 miles detail. To be clear, the list of Snipers with confirmed kills at that range (or higher) is about six people. (There's about four more who are slightly under 1.5 miles, in the 2-2.4km range.) So, that's absolutely something that can be done, but you would be talking about someone who is, literally, one of the best snipers in the world, taking the best shot in their life.
There's nothing wrong with saying you have a character who is that good. But it is the kind of thing you should probably be aware of when you're writing a character if they're among the best in the world.
One famous example of a fumble on this subject would be the original James Bond novels. Flemming somewhat overcompensated, and as a result Bond's described physical regimen becomes borderline parody when you remember that the character is also a high-functioning alcoholic and chainsmoker.
It's also worth remembering, when you are talking about sniping, that the limitations of the weapons are pretty important. One of the snipers mentioned above used a .338, the rest were all using anti-material rifles. (Mostly .50s, but there was also a 14.5mm rifle used in Ukraine, at 2.7km.) So, to hit someone at that range, you're probably using a very heavy gun, designed to take out vehicles.
So, if your setup is someone sniping with a Mk14, or a SCAR, they're probably only good out to about 500m. (A little over a quarter mile.) They might get lucky some day. The world record for a kill with a Remington 700 (technically, an M24) was at 1,250m. So, less than a mile.
Is it weird that someone could be a world class sniper, and still miss a snapshot at close range? Not especially.
Let me define the term snapshot, it's not that complicated, but, it's not really the general term. Snapshooting is the practice of being able fire semi-accurately without aiming. It is a specific skill with firearms. You can think of it as being related to quickdrawing, and while there is overlap between the two, it's not quite the same skill.
Sniping is about taking the time, and accounting for how the bullet will behave as a physical object at extreme ranges. It requires familiarity with your weapon. Not, just the make and model, but the behavior of your specific gun.
There is some basic proficiencies with firearms that are easy to pick up, so it would be somewhat peculiar if you had someone who had extensive experience and training with a rifle, but no comprehension of how to operate a pistol. (You could certainly work out specific counterexamples, but as a general rule you're unlikely to see that.)
It's likely your sniper would be reasonably competent with a handgun. Though there's no reason to assume that you're looking at someone who could hollow dimes at 150m with one.
This leads to a different thought, and it's probably something you want to consider for yourself. Why fire at the pursuers?
The answer you had before might have been as simple as, “well, they're shooting at my character, so of course they'll return fire.”
If you're being pursued, you'll loose speed and time to return fire, even if you're not careful with your shots. Even if you're blindly firing over your shoulder. On it's own, you'd be better off keeping your gun in it's holster, and focusing on getting distance, and finding an escape.
However, suppressing fire can force your pursuers to slow down.
The point of suppressing fire is not to kill your foe. It's a nice perk if it happens, but what you're actually doing is denying spaces they want to move through. Returning fire like this isn't about actually hitting the pursuers, it's about forcing them to slow down and be more careful, while your characters gain distance.
So, does it make sense that a world class sniper would fire blindly over their shoulder at pursuers in order to slow them down, without any real concern over getting precise shots? Yeah. Yeah, that makes perfect sense.
If the point was to kill them, your sniper would want to find someplace with actual cover, preferably on a blind corner, get out of sight, and gun them down when they came around that corner. Like your sniper was a moment ago, they're going to be at a full run. (And, depending on the exact environment, your sniper might be able to hit them from behind, as they run past the hiding spot, or something similar. There are options on how this would work out.) This kind of an ambush is quite doable.
It's always worth remembering, your character's goal in a fight might not be to kill their opponent, and while it might seem irresponsible to use bullets as a general deterrent, that is one of the primary uses of firearms in warfare. Granted, it's not the primary way snipers interact with their weapons, but the fundamentals are still there.
Now, is it possible that a sniper wouldn't even consider using their handgun for suppressing fire? I could believe that. Not because they don't know how, or don't understand the concept, but rather, simply because it's not how they think about using their weapons. Though, again, a character like that is more likely to take the ambush route detailed above.
This blog is supported through Patreon. Patrons get access to new posts three days early, and direct access to us through Discord. If you’re already a Patron, thank you. If you’d like to support us, please consider becoming a Patron.