A self defense firearm should be relied upon to function when you need it to.

There are a ton of aftermarket products for popular handguns like Glocks. It’s possible to build an entire “Glock” pistol without using a single part that’s actually manufactured by Glock.

Some advantages may be gained by replacing certain components, but a self defense firearm, as it comes from the factory, has been tested and tested over again in a variety of circumstances for function and safety. Changing one component could invalidate all of that.

Is having a slightly better trigger worth sacrificing the knowledge that your handgun will function when you need it to?

glock 19
The author’s bone-stock Glock 19. T. Logan Metesh

“What modifications should I make to my new gun?”

That’s a sentence you’ll see or hear ad nauseam if you’ve spent a minimum of five minutes on gun forums, in group pages, or at your local gun shop. The replies to that question are voluminous and varied.

I know people who will switch out the barrel, sights, mag release, and slide lock before ever firing a single round through their brand new gun. I also know people who insist on keeping the gun absolutely, 100% factory stock.

Out of all the comments and suggestions about what modifications should be made, very rarely does anyone bring up safety. Now, I’ll be the first to say it: safety ultimately lies with the user, which is my whole point.

To elaborate …

tungsten guide rod glock
This tungsten guide rod for a Glock costs $89.95.

Parts and More Parts

There are hundreds of thousands of aftermarket parts readily available for every kind of current production gun you can think of. Night sights, spring kits, guide rods, barrels, and so on and so forth. For our purposes moving forward, let’s use the elephant in the room for our example: Glock.

glock parts search results
The internet has everything. A search for “glock parts” returns 29 million hits! Google

There are entire companies that exist solely to sell aftermarket parts for Glock handguns. One company’s website alone ( sees more than 30,000 unique users daily. They ship 1,000 packages a day, employ more than 100 people, and even opened a 50,000 square foot brick-and-mortar store to meet demand.

All. for. Glock. Parts.

custom glock search results on google
The phrase “Custom Glock” has 26.4 million search results. Google

An online search for “Glock parts” returns 29 MILLION results. “Custom Glock” has 26.4 million results. To say it’s a big business would be an understatement.

Gunsmith vs “Gunsmith”

At one time, most every gun owner who wanted to have modifications done to their gun took it to the local gun shop and had their in-house gunsmith do the work for them. Were they all certified master armorers? Undoubtedly, no, but they still were likely to have had more hands-on experience with the inner workings of firearms than the average gun owner.

colonial williamsburg gunsmith shop
Sign from the gunsmith shop at Colonial Williamsburg. CREDIT:

Time marches on, and the Internet—particularly YouTube and other video hosting platforms—have changed everything.

With a couple quick keystrokes, you can find hundreds of how-to videos related to whatever specific modification it is that you’re looking to make to your carry gun—usually you can find one using the exact components you’re dealing with.

Some videos will be done by actual, certified armorers and posted by gun or gun parts companies, while others will be done by your neighbor, or someone even less reputable. Despite their varied skill level and credentials, the platform lends them the same opportunity to appear in search results. And therein lies the problem.

gunsmith modified bolt action
This “gunsmith” took “bolt-action” to a whole different level.

The Purpose of a Carry Gun

You carry a handgun for personal protection—literally the difference between life and death, should the need ever arise. As such, you need to be 100 percent confident that your gun will perform flawlessly when you need it the most.

If someone at the Glock factory screws up, there’s a warranty on their work. Your local gunsmith (should) offer a warranty on their work, but there’s no warranty on your own work.

glock firearms certified armorer badge
You can take a class to become a certified Glock Armorer.

Speaking of warranties, I wanted to know exactly where Glock stands when it comes to making modifications to to their guns, since it’s obviously something that’s being done a lot. Here’s what Brandie Collins, their Public Relations and Communications Manager, had to say:

“The engineers and quality assurance teams at GLOCK thoroughly test and inspect every pistol leaving the factory to ensure it meets the GLOCK standards of quality. When parts are changed once it leaves the factory, it not only compromises the integrity of the pistol as it was manufactured, but it also voids the factory warranty. By modifying components of a pistol, you jeopardize functioning and safety of the pistol.”

(After all, it does say “Perfection” right on the box …)

ultimate pyramid trigger kit
The Ultimate Pyramid Trigger kit is designed for installation by the end-user at home.

Danger of Drop-Ins and Dremels

“Drop-in” modifications are super popular because they just, well, drop in. Anyone can do it and usually without any kind of specialized tools—if you need tools at all.

You can order new guide rods, extended controls, lighter trigger bars, different spring weights, flat face triggers, new sights, and more with the click of a button. Push a couple pins, pop out the old, slide in the new, and voila, you’re done.

Hell, every new Glock ships with a pin punch. It’s like they know you’re a gunsmith. But are you sure that the modifications you made yourself were done properly?

dremel gunsmith perfection patch
Knowing how to use a Dremel does not make you a professional gunsmith.

That can be the danger of drop-in parts. Like the old Geico commercial says, “So easy, even a caveman can do it.” Or, in this case, a Bubba. There’s a reason being called a “Dremelsmith” isn’t a compliment and why one of the best-selling morale patches is shaped like a dremel tool with the words “GUNSMITH PROFESSIONAL” on it.

Just because you can do it, doesn’t mean you should do it.

polymer 80 kits
Polymer80 kits come with a frame, jig, and drill bits to make your own complete pistol frame from an 80% frame.

Or how about companies that make and sell 80% kits? They are incredibly popular right now and it is now possible to build an entirely custom Glock-style pistol without using a single Glock-brand part. With just a couple hand tools that you or your neighbor are sure to have, you can make one of these pistols. (And I think you should; it’s a fun project.)

Countless people have done just that, and I’m sure that quite a few of them use those guns as their everyday carry pistol, trusting their lives to work done at the kitchen table.

complete pistols made with polymer 80 frames
Three complete pistols made on Polymer80 frames. These are completely custom guns.

Before some of you rip off my head and jump down my throat, let me make another statement: certified, professional gunsmiths and master armorers screw stuff up, too. They are human, after all, and are just as susceptible to making errors with drop-in parts as you or I or anyone else in the world.

This leads me to the real point that I want to drive home:

Testing, Testing…

You should function check your gun after modifications are made by you or anyone else, and then shoot the bejeezus out of it to really make sure everything is running as well as it should.

john wick guns
You can have your own John Wick 2 pistol. It costs $1,499.99, gun not included. author photo

That last part is where people can slip up. They paid a professional to do it or they watched hours of how-to videos before actually doing the modification themselves. They’re confident that there’s no way it could have been screwed up, right?

Wrong. At best, confidence and complacency can ruin a gun. At worst, it can kill you.

If you aren’t willing to exhaustively test your firearm after making your own modifications or even after having mods done by a gunsmith, you probably shouldn’t make it your carry gun.

noc agency arms custom pistol
The NOC from Agency Arms is a custom pistol that will set you back $2,999. Agency Arms

I know range time isn’t cheap, ammo can be expensive, modifications can cost princely sums, and none of us have enough free time in our lives to get to the range as often as we’d like, but we have to make the effort—especially with a freshly-modded gun. Don’t just look it over and put it in your holster, confident that you or someone else did everything right.

glock store gun parts
All of the parts for this gun can be purchased separately from GlockStore. They’ll cost approximately $2,300.

I’m not trying to dissuade anyone from modifying a factory gun that they’re going to carry. I have no qualms about anyone paying a professional to do it or having the confidence in themselves to do it at home. If you want to smooth out your action or get a lighter trigger weight, or whatever else suits your fancy, then go for it. I’m just urging you to be smart about it.

Parting Thought

The average person (myself included) who carries a handgun every day for personal protection is highly unlikely to ever shoot enough at the range to really notice the difference between the performance of a factory gun and one that has 10 times the original purchase amount in aftermarket upgrades.

Moreover, if SHTF and you do have to pull your gun in self defense, you won’t notice the 1.5 pound difference in the weight of the trigger pull from that aftermarket connector you installed.

If you read accounts of people who have been in actual combat and gunfights, you’ll notice that the little details tend to fall away in the heat of the moment, when the adrenalin is pumping and fine motor skills are out the window.

Modding guns and testing those mods is a lot of fun and somewhat at the core of certain types of shooting, especially competition shooting—but a carry gun meant for self defense in the most dire of circumstances is not a competition gun, it’s not a race gun, it’s not a hyper accurate target gun, or even a hunting gun. It’s a tool that has to absolutely work when you need it to—a tool you may have to trust your life to, and should be treated as such, in the holster and on the workbench.