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Nighthawk Custom Interchangeable Optic System (IOS): First Look

The Nighthawk Custom Interchangeable Optic System (IOS) allows you to easily switch back and forth between your red-dot optic and traditional sights.

Nighthawk Custom Interchangeable Optic System (IOS): First Look

The IOS uses a tapered slide cut to accept either a blended cover plate with the Novak-pat- tern dovetail for iron sights, or a mounting plate designed to accept popular red-dot sights. IOS plates feature an integral suppressor-height rear sight as a backup to the electronic optic. The design and precision machine work means that you don’t have to re-zero if you change between plates. The IOS is available on new builds as well as a retrofit option for many existing Model 1911s. Cost for the modification is $350 plus $150 for a red-dot-ready IOS plate. (Optic not included.) (Photo by Michael Anschuetz)

Red-dot sights are quickly becoming the norm for pistols. These days, almost every pistol manufacturer is offering red-dot-ready options. Recently, Nighthawk Custom raised the bar with their cleverly designed Interchangeable Optic System (IOS) that allows users to quickly change from a plate with a traditional rear sight to a one with a red-dot sight, and vice-versa.

Why would you change your pistol’s sights? Consider the case of a concealed-carry practitioner who’s just learning to use a red-dot optic. With the IOS, you can train to proficiency with the red dot, yet still rely on the familiarity of traditional sights for carry during the learning curve. 

Interchangeability also enables a user to rotate a single red-dot sight between multiple M1911s with the IOS. Suffice it to say, having the ability to easily transition between a red dot and traditional sights has many advantages.

Nighthawk Custom Interchangeable Optic System (IOS): First Look
An innovative and precisely executed dovetail cut ensures strong and consistent mating between IOS components. IOS slides accept both iron-sight and red-dot mounting plates. (Photo by Michael Anschuetz)

IOS plates are machined from pre-hardened material for durability. Currently, there are plates to accommodate some of the most popular red-dot sights, including the Trijicon RMR (tested), Holosun 507, the Shield RMSc and the Vortex Viper. The plates also feature an integral rear sight that’s tall enough to see through the window of your optic. Interestingly, the low-profile IOS enables you to see a standard-height front sight with a traditional rear sight through the optic’s window.

For personal defense, traditional sight redundancy is critical because even the best red dots can malfunction. In such a case, having a secondary sighting system could be a lifesaver. Unlike some red-dot mounts that obscure a permanently mounted rear sight, the IOS has an integral rear sight that works in conjunction with your red dot.

Nighthawk Custom Interchangeable Optic System (IOS): First Look
The IOS-compatible plates feature a dovetail cut that mates to a corresponding track machined into the top of the slide. Once mounted, the plates are secured by a locking pin and screw. The system is simple and elegant, as expected from Nighthawk. (Photo by Michael Anschuetz)

To remove an IOS plate, use the supplied Allen wrench to loosen the nut atop the plate. Then push the pin out the side of the plate and slide the plate rearward. To install another plate, simply reverse the process. It couldn’t be simpler.

Nighthawk’s tapered dovetail cut is brilliant. It ensures the plate is mounted precisely for a perfect fit with no loss of zero. The IOS is well designed and epitomizes the quality that Nighthawk Custom is known for. If you’re looking for the versatility to switch between a red dot and traditional sights on your M1911, the IOS may be the perfect solution. Visit to learn more.

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