Is there actually any merit to pointing a gun sideways to shoot, or is that just more nonsense put in the “hood” movies just to look cool?
The short version would be to say, “mostly,” and leave it at that, though there’s a lot more information here that can be addressed if you want to dig in. There are a few rare circumstances where it is a valid grip for use in combat.
This is basically trivia, but the grip has been documented in fiction going back over a century, so it’s certainly not just a product of 90s films. That said, the modern use, and it’s place in modern American gang iconography can be traced back to films like Menace II Society.
Due to it’s use in films, and associated with American gang culture, it’s sometimes called, “gangsta style.” At this point the grip is almost exclusively associated with criminal elements, and is a pretty easy way to identify a shooter who doesn’t know what they’re doing.
There’s one big problem, and one myth, associated with it, so let’s take those in reverse order.
The myth is that firing sideways increases the chance of a jam. This doesn’t really make a lot of sense if you know anything about how firearms function. The theory is, that by holding the firearm horizontally, the shell will fail to eject properly, obstructing the ejection port, and causing a failure to feed. The idea behind this is that, somehow, gravity works differently if the gun is held at a 90 degree angle, instead of vertically. The problem with this is, shell casings go pretty much wherever they want. I’ve had off-brand M9 pattern pistols throw shell casings into my face. (I also, hate M9s as a result.) Because of how the case ejection system works in most handguns, you can fire them from pretty much any position without issues.
The problem is, most people side shooting will sight across the side of the slide. This, doesn’t work. Unless you’re standing next to the target, you need to use the sights to put a round where you want it.
There’s another accuracy factor, most competent shooters will brace their handgun with both hands. This stabilizes the pistol, and allows for far more accurate shooting. Side shooting will almost always result in the weapon, unsupported, at arm’s length. This results in greater barrel shake, and less recoil control. Even if you’re using the sights, it will be less accurate on the first shot, and recoil will be more severe.
So, I said there were some uses for this shooting position. I have a few specific examples, though there may be others.
Center Axis Relock is a modern Close Quarters Combat shooting stance popularized in films like John Wick, and video games like the Splinter Cell series.
CAR pulls the firearm closer to the body in comparison to a normal Weaver stance. This causes the user to raise their shooting arm’s elbow to partially protect their face, and rotates the firearm to a 45 degree angle. In some circumstances the user may raise their arm further, fully shielding their face on that side and rotating the firearm horizontal. Throughout all of this they will still be sighting using the handgun’s iron sights, additionally, they will keep their off hand on the firearm stabilizing it.
Worth noting, from a 45 degree angle, your shooting arm will not obstruct your vision on that side, raising it to horizontal will, making this less appealing unless necessary. For example: if there is a bright light shining in the user’s eyes from that direction, raising the arm will allow them to block that distraction.
The major advantage of CAR is that it’s incredibly difficult to safely disarm the user.
One of the few situations where someone will adopt a side shooting stance, basically without modification, is if they’re firing from behind a riot shield. These fully occupy one of the shooter’s hands, and partially obstruct their other hand. In most cases, the shield will include a transparent section to allow the user to see what’s on the other side without exposing themselves to incoming fire. In situations like this it is possible the operator will simply reach around the shield, line their sidearm up with the window, and fire. To be fair, a competent shooter in this situation will still attempt to use the firearm’s iron sights, however, because of the shield, and having to reach around it, the gun will be at a horizontal, or nearly horizontal, angle.
The third situation is far more contextual. In an emergency, a trained operator may aim and fire without adjusting their stance. Because of how your arm is put together, quickly firing to the left or right (depending on your firing arm) without adjusting your chest’s position, will result in the gun being at near horizontal. Also worth noting in situations like this, firing behind you will often result in the handgun being held upside down. This is less, precision shooting, and more, desperate reflexes, though. SWAT and similar groups will practice firing from these positions, however.
Note: You can correct the angle of your arm to keep the pistol vertical while adjusting, it is simply faster to pivot the entire arm, rotating the pistol.
There is a fourth situation which is particular to rifles. While firing from a prone position with a protruding box magazine (so, most assault rifles), some shooters will opt to rotate the firearm, rather than lift themselves up, exposing themselves to enemy fire. Depending on range there are a lot of factors to consider here, but in some situations, this is the best option available.
Another possible variant is operating a firearm in very tight spaces, such as cramped service passages, or those mythical air ducts that are large enough to allow a grown human to crawl around.
Usually, it’s either to look cool, and anyone who habitually draws their handgun in a side shooting stance is a pretty good indicator that they don’t know what they’re doing. For some writers, this stance is synonymous with criminals. An undercover cop may use a stance like this while protecting their cover, even though it runs contrary to their training.
Also, worth noting that it’s entirely possible to meet gang members who’ve had military firearms training, and as a result know exactly how to handle their firearms. At which point you wouldn’t see something like this.
Some writers may not realize that this stance doesn’t work, or is sub-optimal, and may imbue it with special characteristics. That’s, simply, not the case. There are good reasons that almost no one who knows what they’re doing would ever use this stance.