Holster Compatibility and Aftermarket Pistol Frames

Aftermarket frames and grip modules for your pistol can provide a lot of great improvements over factory pistol frames. But they can also affect your holster's fit. Many aftermarket frames change critical dimensions that holster manufacturers use to control the pistol's retention and stability in the holster.

This article applies to inside-the-waistband kydex holsters.

Table of Contents

• Safety risks of poor holster fit
• Which holster dimensions are critical?
  • How does changing the frame affect retention?
  • What about adjustable retention holsters?
• Are PHLster holsters compatible with aftermarket pistol frames?
  • Compatible
  • NOT Compatible
• Should you modify your holster?
• "It works for me" and other fairy tales

If you fail to check for holster compatiblity before adding an aftermarket pistol frame or aftermarket grip module, at best you could end up with a holster that fits and feels... kinda crappy. At worst, you could end up shooting yourself, or watching your gun skidding away across pavement in the Walmart parking lot -- all because you didn't realize your aftermarket frame would change your holster's fit and retention.

Carrying a gun is an inherently dangerous activity, and it's on you to make sure you're doing it safely, ESPECIALLY if you're adding custom parts. Safety risks of poor holster fit include:

• Improper retention
  • Gun falls out of holster
  • Retention feel is incorrect or inconsistent
  • With an adjustable retention holster, you may have to tighten the retention down so far that it weakens the holster materials
• Improper trigger protection
  • Some aftermarket frames (especially those with weapon-mounted lights) may affect how far the gun can be inserted into the holster, which can leave your trigger exposed
• Decreased holster durability
  • If an aftermarket frame puts excess pressure on the holster, it can cause the holster to fatigue and fail prematurely
• ANY OF THE ABOVE CAN LEAD TO A RISK OF SEVERE INJURY OR DEATH

It's a loaded gun. In your pants. Be cautious, and don't assume it will be fine. Just because someone will sell it to you doesn't mean it's safe.

This is a complicated question, but we'll break it down to the simple basics for this article. (If you want more detailed information about holster making, check out the kydex holster how-to videos on our YouTube channel.)

Speaking very generally, any part of the gun that lies beneath the kydex will be at least somewhat important for holster fit. If an aftermarket pistol frame or grip has protrusions, larger/smaller dimensions, or a different radius on certain curves, it probably won't fit a holster made for the factory version of that gun. The same applies for stippling or texturing that could interfere with holster fit. In fact, assume it WON'T fit until you contact the holster manufacturer to confirm.  

When we make a kydex holster, we use very specific clearances and contact points inside the holster. These are designed to touch very specific parts of the gun. That way, when the gun is inside the holster, it fits cleanly and retains correctly, without wobbling or rocking.

But when those gun dimensions change, you may end up with a contact point inside the holster that's touching ... nothing. Just hanging out there unsupported.  

Of course you can also have the opposite problem. If your aftermarket frame has larger dimensions, or protrusions, you could end up with parts of the gun making contact with the holster where they shouldn't. A big protrusion on your gun's frame is like a rock in your shoe -- it creates a pressure point and displaces everything around it, leading to an insecure or uncomfortable fit.

Aside from the deep eldritch horror of sloppy holster fit (this makes us twitch here at PHLster), poor fit can also cause safety issues, as you'll see in the next section.

Retention means making the gun stay inside the holster when you need it to stay, while still being accessible for a safe and unobstructed draw. (Side note: impress your friends at parties by explaining to them why you don't shake your holster upside down to test retention.)

In the video above, you can see the kydex holster flex when it encounters the trigger guard of the gun. Once the gun is fully inserted, it snaps back into place, retaining the gun securely. That's because the holster is molded to the exact shape of the trigger guard. If your aftermarket frame changes the shape or dimensions of the trigger guard, that will change the retention characteristics of the holster. And that's where you run into problems.

An aftermarket frame can make the holster's retention feel too tight, or it can dump your gun on the ground. When the parts of the holster that control retention don't fit right, you can run into major safety issues. See how the holster above snaps back when the gun is fully inserted? If the frame is the wrong size or shape, it can't do that.

That concept also applies to other frame dimension changes, aside from just trigger guards. Say there's a bump somewhere along the frame, like a gas pedal or thumb ledge. That could change the angle of the kydex enough that you no longer get safe retention, even if you somehow manage to cram the gun into the holster. Basically, any time the holster isn't molded for the specific dimensions of the frame, you lose control over the retention. And that's dangerous.

Factory frame vs aftermarket frame. Note the major difference in trigger guard shape.

Some adjustable retention holsters will work with some aftermarket frames and grip modules, but contact the holster manufacturer to check prior to purchase. Please don't assume it will work without asking them. This is an area where close enough ISN'T good enough. A precision molded holster requires certain specifications to work correctly. You can't just change things and hope for the best.

NOTE:  Because most custom frame and grip manufacturers are NOT also holster manufacturers, they don't always know what dimensions are critical for holster fit, and they may make questionable recommendations. The final authority on whether an aftermarket frame or grip fits a certain holster lies with the holster manufacturer.

PHLster holsters are precision formed for exceptional fit and retention with factory frames. So using any aftermarket frame that deviates from factory frame dimensions is generally a no-go. Most aftermarket frames and grip modules are NOT compatible with PHLster holsters, with a few exceptions, explained below.

Here's a partial list of frames and grip modules that do NOT work with PHLster holsters. There are many aftermarket frame companies, and we don't keep track of them all. Assume your aftermarket frame will NOT fit unless it is specifically exempted in the next section. If in doubt, don't try it out.

Not compatible:

• Icarus Precision
• Mischief Machine
• Odin Armory
• GoGuns
• Shalotek
• Sharps Bros
• Juggernaut
• Smith Defense
• Wilson Combat Macro Short
• Literally anything with a gas pedal, thumb ledge, or other "recoil control" device

The specific frames and grip modules listed here ARE compatible with PHLster holsters for their respective gun models. Note that only these specific grip modules are confirmed compatible. If it's not on this list, assume it won't work. Please contact us prior to purchase if you have any questions.

Compatible Frames:

• Boresight Solutions Competition Series - for P365 variants and Glock variants
• Boresight Solutions Duty Series - for Sig and Glock variants
• Wilson Combat - WCP365 XL
• Wilson Combat - WCP365

No.

A common myth you'll hear all over the Internet is that you can simply heat up your holster with a hair dryer or heat gun and remold it to fit an aftermarket frame. DO NOT DO THIS. It's a very bad idea. Heating up your holster softens it up and makes it lose its shape. That means you run the risk of losing definition on important holster features that are essential for safety and retention.

I'm going to be honest here, even though it may hurt some feelings. If you had enough knowledge to remold your holster safely with a heat gun, you wouldn't need to buy a holster in the first place -- you'd already know enough to make your own. (If you want to learn holster making, we have resources for that, too. But don't buy a holster only to ruin it with a hair dryer.)

You're carrying a loaded gun in your pants. Treat it with the appropriate level of respect, and don't put your life at risk with sketchy homemade holster mods.

And another note: Just because sum dood on the Internet said it "works for him," doesn't mean it's actually advisable or safe. "It works for me" is a lazy answer that indicates lazy thinking. In almost every case, the "it works for me" guy hasn't done any kind of safety or quality testing. He thinks it "works" because he hasn't tried very hard to find its failure points. Putting a holster on and walking through a Walmart parking lot is not an appropriate level of testing for lifesaving safety gear, but it's exactly the level of testing you can expect from the average Internet commentator. Don't take anyone's word as gospel, do your own research, and take full responsibility for your own safety.

If you have any questions or concerns, please feel free to contact us any time, and we'd be happy to help.