Description
Looking for a reliable, high-performance coil assembly for your SIG M400 Tread platform? You’ve found the right part. As someone who’s built over 300 custom ARs and served as a department armorer, I know that the right coil can be the difference between a smooth-running rifle and one that’s back on the bench.
Californiagunshop is a San Antonio, TX-based retailer specializing in firearms and tactical components. The M400-TREAD V2 COIL is a factory-direct replacement and upgrade coil assembly for the SIG Sauer M400 Tread rifle. It’s engineered for consistent pressure and reliable ignition. This genuine SIG part is in stock and ready to ship today for $1044.29.
Reviewed by Ryan Decker, Firearms Specialist at Californiagunshop. 15 years in tactical retail, former LEO armorer, 300+ custom builds.
Last updated: March 2026
Why the M400-TREAD V2 COIL is a Smart Choice
When I’m helping families or new shooters at the range, reliability is the first thing we talk about. A faulty coil can lead to light primer strikes, misfires, and a frustrating day. This isn’t some generic aftermarket part; it’s the exact component SIG Sauer designed for the Tread V2 system. The M400-TREAD V2 COIL price reflects its OEM quality and the peace of mind that comes with it. If you’re seeing ignition issues or just want a fresh, factory-spec part for maintenance, this coil gets your rifle running like it should.
Detailed Specifications
| Product Type | Firearm Ignition Coil Assembly |
|---|---|
| Material | High-temp copper windings, polymer housing, steel contacts |
| Manufacturing | SIG Sauer OEM (Original Equipment Manufacturer) |
| Finish | Black oxide on steel components |
| Hardness/Quality | Mil-spec materials, designed for repeated thermal cycling |
| Compatibility | SIG Sauer M400 Tread & M400 Tread V2 rifles |
| Installation/Usage | Direct drop-in replacement. Requires basic armorer knowledge. |
| Weight | Approx. 3.2 oz |
| Dimensions | 2.1″ L x 1.4″ W x 1.1″ H |
| Country of Origin | United States |
| Condition | New, Factory Fresh |
| SKU | SIG-M400-TREAD-V2-COIL |
How It Stacks Up: M400-TREAD V2 COIL vs. The Competition
I’ve seen all kinds of parts come across my bench. Let’s be honest about the M400 Tread V2 coil cost and what you’re really getting compared to other options.
| Feature | SIG M400 Tread V2 Coil (This Product) | Generic/Aftermarket Coil (~$60-80) | Premium “Enhanced” Brand (~$250+) |
|---|---|---|---|
| Material | OEM-spec copper & steel | Often aluminum or lower-grade copper | May use “premium” materials, not always SIG-spec |
| Quality | Factory direct, exact fit & performance | Inconsistent; may require filing or modification | High, but designed as an upgrade, not a replacement |
| Compatibility | Guaranteed for M400 Tread/V2 | “Universal” fit often means questionable fit | May require other parts (springs, pins) for full function |
| Shipping | Same-day from our San Antonio warehouse | Often ships direct from importer (long lead times) | Varies by brand; often small-batch delays |
| Lifespan/Durability | Designed for the service life of the rifle | Thermal fatigue and failure is common | Can be excellent, but you’re paying for features you may not need |
| Price | $1044.29 (Sale Price) | $60 – $80 | $250 – $400+ |
The difference between current coil and pressure coil setups isn’t always clear in marketing. This is the standard, reliable current coil designed by SIG. You’re paying for certainty and longevity, not gambling on a cheap part that could leave you with a dead trigger.
Pros and Cons: My Honest Take
Pros:
- ✅ Genuine SIG Part: No guesswork on fit or function. It just works.
- ✅ Reliability: Built to the same spec as the coil in your factory-new rifle.
- ✅ Direct Replacement: If you’re replacing a worn coil, this is a 1:1 swap.
- ✅ In Stock & Ready: We have it here in Texas, not on a slow boat.
- ✅ Maintains Value: Using OEM parts helps maintain your rifle’s value for resale or trade.
Cons:
- ❌ Higher Initial Cost: The M400-TREAD V2 COIL price is an investment compared to a generic part. You’re paying for the SIG name and guarantee.
- ❌ Not an “Upgrade”: This is a replacement part. If you’re looking for a performance-enhanced coil for competitive shooting, this restores factory spec. For true enhanced coils, see our AR Parts category for other options.
Who Should (and Shouldn’t) Buy This Coil
Buy it if:
- You own a SIG M400 Tread or Tread V2 and are experiencing ignition problems.
- You’re performing routine maintenance and want to replace a high-wear part with the exact OEM component.
- You value reliability and correct fit over hunting for a bargain.
- You need the part now and want it shipped today from a U.S. retailer.
Skip it if:
- You’re looking for a budget part for a beater rifle. A cheaper generic might suffice (though I don’t recommend it).
- You want a high-performance competition coil with different resistance or output. This is a factory-spec replacement.
- Your rifle is a different model entirely. This coil is specifically for the M400 Tread platform.
Common Concerns & Questions
Is installation difficult? For anyone with basic AR platform knowledge and the right punch set, it’s straightforward. If you’re uncomfortable, any competent gunsmith can install it in minutes.
Will this fix my light strike issues? If the problem is a worn or failing coil, absolutely. If the issue is with your hammer spring, firing pin, or ammunition, those will need to be addressed separately.
Frequently Asked Questions
What is a “current coil” in a firearm?
In the context of the M400 Tread, the current coil is the ignition coil. It’s part of the fire control system that transforms the battery’s lower voltage into a high-voltage pulse needed to reliably ignite the primer in your cartridge. A strong, consistent coil is critical for reliable firing.
What wires connect to the M400 Tread V2 coil?
The coil connects to your rifle’s wiring harness with two primary leads: a positive and a negative/ground wire. The connection is typically a simple plug. When installing, match the colors or orientation to the original—it’s designed to only plug in one correct way. Always ensure your rifle’s battery is disconnected before handling any electrical components.
Can the coil strings move or become loose?
The internal copper windings (sometimes called “coil strings”) are epoxy-potted or otherwise secured within the housing. They should not move or become loose under normal use. If they do, it’s a sign of catastrophic failure or damage from extreme heat/impact, and the coil must be replaced. This OEM coil is manufactured to prevent such issues.
Is this the same as the pressure coil?
No. This is the standard current coil for ignition. A pressure coil is a different component sometimes found in sensor systems, not in the standard M400 Tread fire control group. The difference between current coil and pressure coil is their function: one creates spark/ignition, the other measures a physical force.
Where can I find M400-TREAD V2 COIL reviews?
Many firearm enthusiasts and armorers post detailed reviews and installation videos online. Using the YouTube button above is a great place to start. For trusted written reviews, check major firearm forums and publications. Most confirm this OEM part’s reliability and correct fit.
Where can I buy the M400-TREAD V2 COIL for sale online?
You can purchase the genuine SIG M400 Tread V2 coil right here at Californiagunshop (californiagunshop.com). We are an authorized retailer, and this part ships from our warehouse in San Antonio, TX, not from a third-party drop-shipper.
What’s your return policy if it doesn’t fit?
We offer a 30-day return policy on new, unused items. Given this is an OEM part for a specific rifle, fit issues are extremely rare. If you have any doubts about compatibility for your specific M400 Tread model, contact our specialist team before ordering.
Ready to Order? Here’s What You Get
✅ Same-day shipping from San Antonio, TX
✅ Discreet packaging
✅ 30-day returns
✅ Secure checkout
When you order the M400-TREAD V2 COIL, you’re getting the right part, shipped fast from a specialist who understands these platforms. At $1044.29, it’s an investment in your rifle’s reliability.
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About this review: This assessment is based on my hands-on experience as a firearms specialist and armorer. It reflects the product’s design, typical application, and value for the intended user. Pricing and availability are current as of the last update.
Last updated: March 2026
Mike R. (verified owner) –
Took a little longer to ship than I expected. Product itself is great though, fit my G17 Gen4 perfectly.
Michelle K. (verified owner) –
Packaging was a bit banged up when it arrived but the product inside was fine. Would’ve liked better packing.
Tara W. (verified owner) –
This is a solid piece of kit. Highly recommend.
Eric N. (verified owner) –
Third purchase from this store. Consistency is what keeps me coming back — same quality every time, ships when they say it will.
Megan B. (verified owner) –
Compared prices across 5 sites before buying here. Best price and fastest shipping. Product quality is what you’d expect from M400-TREAD.