BUIS – Backup Iron Sights for AR-15

Q: What are the best BUIS for AR-15 rifles?

Top BUIS for AR-15 rifles include Magpul MBUS Pro, TROY BattleSights, and Trijicon models. The best choice depends on whether you prefer flip-up, fixed, or offset sights.

Q: Do BUIS work with red dots and scopes?

Yes. BUIS can co-witness with red dots or serve as a backup sighting system when using scopes or magnified optics.

Q: What’s the difference between flip-up and fixed BUIS?

Flip-up BUIS fold down when not in use and deploy instantly, while fixed BUIS remain upright and ready at all times for maximum simplicity and durability.

Q: Are offset BUIS worth it?

Offset BUIS are mounted at a 45-degree angle, allowing you to tilt your rifle to quickly transition from optics to irons, making them ideal for tactical and competition use.

45 Degree Iron Sights

Sight Tools

Polymer BUIS

**A.R.M.S. #40 Flip Up Rear Sight** $160.00

A.R.M.S. #40L Rear Sight - Low Profile Flip UP Sight $170.00

**PRI Flip up Front Sight with .750" gas block** $186.00

**PRI .625 Gas Block Flip Up Sight** $191.00

**PRI Rail Mounted Flip Up Front Sight** $122.00

**Trijicon AR-15 Night Sights 3 Dot Sight Set - CP25** $81.01

**Trijicon AR-15 Green Front Night Sights - CP25F** $58.80

**Magpul MBUS Pro - Magpul Back-Up AR-15 Sight Set - Front & Rear** $180.40

**Magpul MBUS Set (Front & Rear) - GEN 2 with Free MSP Silicone Gun Cloth** $88.35

**Magpul MBUS Pro Set - Magpul Back-Up AR-15 Sight Set - Front & Rear w/ Free MSP Silicone Gun Cloth** $180.40

**Magpul MBUS Pro LR Adjustable Sight Rear** $132.95

**Magpul MBUS Pro Offset Sight Rear** $104.45

**Magpul MBUS Pro Sight – Rear** $109.20

**Magpul MBUS Pro Offset Sight Front** $85.45

**Magpul MBUS Pro Sight – Front** $90.20

**A.R.M.S. #71L series, Front Sight** $68.00

**A.R.M.S. #71L Flip Up Sights (Front and Rear Set)** $144.00

**A.R.M.S. #71L series, Rear Sight** $90.00

**Samson Quick Flip Front & Rear AR Sight Package** $185.25

**Samson Flip Up Sights Package (Manual) HK Front w/ A2 or SP Rear** $134.19

**Samson AR15 Fixed Sights - Front & Rear Package with HK Front/A2 or SP Rear** $111.58

**Samson Gas Block Height Quick Flip Front & Rear Sight Package** $190.81

When it comes to reliability, nothing beats a solid set of BUIS (Backup Iron Sights). Whether your optic fails, your red dot runs out of power, or you just prefer the confidence of having irons ready, BUIS are a must-have for any serious AR-15 or tactical rifle setup. At Mounts Plus, we carry a wide selection of backup iron sights—from flip-up BUIS to fixed and offset options—so you can find the perfect solution for your build.

Why Choose BUIS?

Redundancy: Always have a dependable sighting system ready.
Compatibility: Works with red dots, LPVOs, and magnified optics.
Variety: Available in flip-up, fixed, and offset 45° configurations.
Durability: Designed to withstand recoil and harsh field conditions.
Versatility: Ideal for AR-15 platforms, carbines, and other Picatinny-equipped rifles.

Types of BUIS We Offer

Flip-Up BUIS

These sights fold down when not in use and flip up instantly when you need them. Popular for shooters running optics who want a low-profile backup.

Fixed BUIS

Always ready and extremely rugged, fixed BUIS are the go-to for shooters who prioritize simplicity and strength.

Offset BUIS (45° BUIS)

Mounted at a 45-degree angle, these allow you to run optics while keeping irons instantly accessible with a slight rifle tilt. Perfect for competition or tactical use.

Top Brands in BUIS

We stock BUIS from trusted names like:

Magpul (MBUS, MBUS Pro)
TROY Industries (BattleSights)
Trijicon
Samson Manufacturing
Precision Reflex (PRI)

Each brand is chosen for its quality, durability, and real-world performance.

How to Choose the Best BUIS for Your Rifle

Material: Polymer BUIS are lightweight and affordable, while steel/aluminum BUIS offer maximum durability.
Mounting System: Ensure compatibility with your Picatinny or MIL-STD rail.
Style: Decide between flip-up, fixed, or offset depending on your optic setup.
Budget vs. Performance: Brands like Magpul MBUS deliver solid performance at great value, while TROY and Trijicon offer premium solutions.

✅ Frequently Asked Questions (FAQ)

Q: What does BUIS mean in firearms?
A: BUIS stands for Backup Iron Sights, a secondary sighting system used when optics are unavailable or fail.

Q: What are the best BUIS for AR-15 rifles?
A: Popular options include Magpul MBUS Pro, TROY BattleSights, and Trijicon iron sights. The best choice depends on whether you want flip-up, fixed, or offset BUIS.

Q: Do BUIS work with red dots and scopes?
A: Yes. BUIS are designed to co-witness with red dots or provide a backup when using magnified optics.

Q: What’s the difference between flip-up and fixed BUIS?
A: Flip-up BUIS fold down for a low profile and deploy when needed, while fixed BUIS are always up and ready for immediate use.

Q: Are offset BUIS worth it?
A: Offset BUIS allow you to keep your optic mounted and simply tilt your rifle to use irons, making them especially useful in tactical and competition shooting.

🔗 Shop BUIS at Mounts Plus

At Mounts Plus, we make it easy to find the best BUIS for AR-15 rifles and tactical carbines. With top brands, competitive pricing, and a wide range of flip-up, fixed, and offset BUIS, we have the right sighting solution for every shooter. Browse our collection today and upgrade your rifle with the backup iron sights you can trust.