Mounting Made Easy: Ultimate Red Dot Screw Pack

By Joe Kriz


In theory, mounting a red dot to a handgun is easy. You have a gun, an optic, matching adapter plate, pins, dovetail mount, or milled slide, and provided screws to secure the optic to the gun. But, in practice, the process is often easier said than done. Why is that?

Simply put: a lack of industry standards. Not only are there over half a dozen optic footprints (e.g., RMR, RMSc, etc.) shared by pistol dots on the market, but many firearm manufacturers also have their own mounting systems (e.g., Glock MOS). Other non-standardized variables include optic deck height and slide/plate thickness, as well as screw length, thread pitch, and head design.

Handgun manufacturers try to account for such variables by providing multiple adapter plates and screw sets with guns, but accommodating consumers and the growing number of options has become increasingly difficult. Some have even begun limiting provided adapter plates to one or two footprints, forcing customers to conform or purchase additional plates from them or third parties to mount their desired optic. Similarly, it’s impossible for optics manufacturers to provide screws for mounting their pistol dots to every handgun on the market.

That is, before we introduced the Swampfox Ultimate Red Dot Screw Pack.

Understanding Screws

Before diving into what comes in the pack, let’s generally talk about screws – types, sizing, and features. Understanding these concepts will make selecting hardware and mounting optics easier.

Metric vs. Imperial

There are two types of screws: metric and imperial. Though imperial is the American standard, many firearms are made around the world or by international parent manufacturers, meaning many handguns use metric. Here’s how to read the sizing of each:

Metric Screws

Metric screws will be noted with the letter M, followed by a number expressing the outer diameter of the thread in millimeters (mm). For example, M4 would denote a metric thread with an outer diameter of 4mm. The larger the number, the wider the diameter of the screw.

The second half of metric screw dimensions is the thread pitch, or the distance between two thread peaks, measured in mm. The standard thread pitch of a M4 screw is 0.70mm. The larger the number, the wider the gap between threads.

Together, the screw might be labeled M4x0.70.

Imperial Screws

Imperial, or U.S., fasteners are often prefaced with a pound sign (#) noting the screw gauge, or outer diameter. The larger the number, the larger the screw’s diameter. For example, a #4 screw is a larger gauge and diameter than a #3. It’s also worth noting that screw diameter may be expressed as a fraction (e.g., 1/16”) instead of gauge.

Unlike the metric system, though, imperial uses Threads Per Inch (TPI), or thread count. A #4-40 screw would have a thread count of 40 threads per inch. Overall screw length may also be included in the screw description, measured in inches (e.g., #4-40-3, representing 3 inches).

Screw Heads

If you’ve ever changed batteries in a toy or built IKEA furniture, you’ve likely seen screws of various sizes and styles. Some screws may have flat heads, while others may be oval. Screw heads may also be flat or beveled underneath. Our included screws have 5.0-5.5mm diameter oval shape heads, with most sets having a newer 90-degree underhead.

Though angled screw heads can provide additional compression when seated for enhanced thread binding/locking, they require a thicker optic base to account for the longer head design. With the use of included Loctite on the screw threads, we’ve found flat head screws provide sufficient thread lock in a more compact package.

While flathead and Phillips head screws are used on optics, most pistol red dot screws require the use of a Torx wrench – identified by the star or asterisk-shaped end/socket – to tighten. Ours specifically use a size T10, which is included with every optic.

Screw Length

Every screw has an effective, overall length, or the distance from the end of threads to the screw head’s widest diameter. However, because the optic base/body is sandwiched between the handgun slide and the screw head, only part of the screw’s overall length is used. We call this remaining length the “stick out” dimension.

Too much stick out, and the screws may interfere with handgun internals or lead to a loose fit. Whereas too little stick out, and the screws may be too short to get a secure lock on the slide, possibly sending your optic down range or back into your face when shooting.

Now that we’ve covered some of the technical aspects of screws, let’s get into the Ultimate Red Dot Screw Pack itself.

Ultimate Red Dot Screw Pack

The Swampfox Ultimate Red Dot Screw Pack provides replacement and do-it-yourself (DIY) screws for mounting red dot optics to popular handgun models. The only mounting solution of its kind in the industry, the all-in-one pack was developed to better serve our customers and optics-ready handgunners.

What's In the Pack

Included in the pack are two pairs of 16 sets of screws (64 total) to be used with specific Swampfox optics (with and without our protective Ironside Shield) and specific firearms, as well as extra-long screws designed to be trimmed to fit.

Inside the box, bagged and labeled screw sets are divided between five larger bags:

Replacement: Swampfox Optics (RMR)

Optics include: Kingslayer, Liberty (Gen 1), Justice (Gen 1), Liberty II, Justice II

Included screws:

  • M3.5x0.60 (1913 Picatinny profile base)
  • #4-40 (RMR slides with recoil lug posts)
  • #6-32 (RMR slide without recoil lug posts)
  • #6-32 (Glock MOS, except G43X/G48 MOS)

Replacement: Swampfox Optics (RMSc)

Optics include: Sentinel (Gen 1)

Included screws:

  • M4x0.70 (Canik pistols)
  • M4x0.70 (Springfield Hellcat/Hellcat Pro)
  • M3x0.50 (SIG Sauer P365 variants)

Replacement: Swampfox Optics with Ironsides Shield

Included screws:

  • M3x0.50 (Sentinel Gen 1 + Ironsides Shield, Canik pistols)
  • M4x0.70 (Sentinel Gen 1 + Ironsides Shield, SIG Sauer P365 variants)
  • #6-32 (Liberty/Justice Gen 1 + Ironsides Shield)

FN /SIG Sauer Series Pistols

Included screws:

  • #6-40 (FN MRD pistols, except Reflex MRD/SIG Sauer P320 variants)

DIY / Extra Screws

Included screws:

  • M3x0.50
  • M3.5x0.60
  • M4x0.70
  • #4-40
  • #6-32

Intentionally left long, our DIY screws can be fine-tuned for a wider range of handguns, optics, and adapter plates. Simply grab a metal file, Dremel, or belt sander, and with careful trial-and-error, trim them for a custom fit.

But be careful, if you feel friction or resistance against the screws when torquing down, they may be too long. To ensure a proper and safe fit, load a few snap caps/dummy rounds into a magazine and test functionality of pistol. If you feel binding or hear scraping, remove more material from the screws.

Why You Need It

If you currently shoot with a red dot, just purchased your first optic, or are considering getting your first pistol dot sight, the Ultimate Red Dot Screw Pack is for you.

Due to lacking industry standards and the growing number of options on the market, there’s no guarantee the screws that come with your firearm, red dot, or aftermarket adapter plate will work with your optics-ready setup. Plus, it never hurts to have backup hardware in the case you strip or lose the screws you have.

Whether you use Swampfox, Holosun, or Vortex optics, or shoot Glock, SIG Sauer, or Smith & Wesson handguns, the Ultimate Red Dot Screw Pack is the one-size-fits-all solution for obtaining a secure mount you can trust in competition, on duty, and at home.

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Screw Pack FAQs

Can screw sets be purchased separately outside of the pack?

No; included screw sets can only be obtained with the purchase of new Swampfox optics/accessories or the Ultimate Red Dot Screw Pack. Customers with specific screw needs should contact our customer service team at or

Can screws be used with other optics?

Yes; while the Ultimate Red Dot Screw Pack is intended to be used with Swampfox optics/accessories, the included replacement and DIY screws can fit other optics on the market. However, we cannot assist customers with questions regarding the use of the pack with non-Swampfox optics.

Will more screws be added for other optics/pistols?

The Ultimate Red Dot Screw Pack was recently updated with two new screw sets: #6-32 screws for Glock 19 MOS, and #6-40 screws for FN Series pistols. Additional screw sets may be added in the future based on consumer feedback and demand. If you know of a screw size/pitch missing from the pack, contact us so our team can assess the possibility of having it added.

Where can I get screws not included in the pack?

For replacement screws not included in the Ultimate Red Dot Screw Pack, or if you don’t know what screws your optic/gun requires, we recommend contacting the optic/firearm/adapter manufacturer directly for assistance. Swampfox customers may contact us here. Additional screws can be found online or at local hardware stores, such as Ace Hardware.

What is the recommended torque for tightening screws?

Necessary torque can vary based on screw size and mounting optic/handgun. We recommend contacting the optic/firearm/adapter manufacturer directly for assistance. Swampfox customers should contact us directly for torque specifications for our specific optics.

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