The Smith & Wesson M&P 15 is a popular AR-15 platform rifle, appreciated for its reliability and versatility. One aspect often considered by owners is the barrel threading, crucial for attaching accessories like muzzle brakes, flash hiders, and suppressors. This guide delves into the specifics of M&P 15 barrel threads, addressing common questions and offering valuable insights.
Understanding Barrel Threads on the M&P 15
The most common thread pitch found on M&P 15 barrels is 1/2x28 TPI (Threads Per Inch). This is the standard for .223/5.56 NATO barrels and ensures compatibility with a wide range of aftermarket accessories. However, it's crucial to verify the thread pitch on your specific M&P 15 barrel before purchasing any attachments. The specifications can be found in the firearm's manual or stamped on the barrel itself. Failure to match the thread pitch can lead to improper attachment, potential damage, and safety hazards.
Why is Thread Pitch Important?
The thread pitch dictates the number of threads per inch. A mismatch means the accessory won't screw on correctly. Forcing an incorrect attachment can damage the threads on both the barrel and the accessory, rendering them unusable. This is why verifying the thread pitch is paramount before making any purchases.
Identifying Your M&P 15 Barrel Threading
There are several ways to identify the threading on your M&P 15 barrel:
- Check the Owner's Manual: The owner's manual should clearly specify the barrel specifications, including the thread pitch. This is the most reliable source of information.
- Inspect the Barrel: Carefully examine the barrel near the muzzle. Sometimes, the thread pitch is stamped directly onto the barrel itself.
- Use a Thread Gauge: A thread gauge is a tool with various thread pitches that you can use to check the barrel's threading. This provides a precise measurement.
- Contact Smith & Wesson: If you're still uncertain, contacting Smith & Wesson customer support directly is always a viable option. They can provide definitive information based on your firearm's serial number or model.
Common Accessories for Threaded M&P 15 Barrels
Once you've confirmed your barrel's thread pitch, you can choose from a variety of accessories to enhance your M&P 15's performance and functionality. These include:
- Muzzle Brakes: These reduce recoil and muzzle rise, improving shooter control and follow-up shots.
- Flash Hiders: These mitigate the bright flash produced when firing, which can impair night vision and compromise the shooter's position.
- Suppressors: These significantly reduce the sound and flash of gunfire, offering hearing protection and tactical advantages. Note that suppressor ownership and use are subject to federal and state regulations.
Safety Considerations When Working with Threaded Barrels
Always prioritize safety when handling firearms and accessories:
- Proper Tool Usage: Use the correct tools to attach and remove accessories. Over-tightening can damage the threads.
- Thread Lubricant: Applying a small amount of thread lubricant can make installation and removal smoother and prevent damage.
- Professional Assistance: If you're unsure about any aspect of working with threaded barrels, seek assistance from a qualified gunsmith.
Conclusion
Understanding the threading on your M&P 15 barrel is essential for safe and effective accessory use. Always verify the thread pitch before purchasing any attachments, and prioritize safety throughout the entire process. By following these guidelines, you can ensure your M&P 15 remains in top condition and performs optimally.