The Evolution IV Revolver Hammer Kit from Apex Tactical Specialties doesn’t just drop into your Smith & Wesson frame—it rewires the action. Designed with the same pinned sear and stirrup found on the Performance Center hammer, this kit replaces factory MIM components and, when properly tuned, can drop a 12+ lb DAO trigger pull to a competition-ready 4.0 lbs. That’s not a typo. You’ll want to handload at that point. Converts your revolver to Double Action Only (DAO) for consistent, repeatable trigger breaks.
| Manufacturer | Apex Tactical Specialties |
|---|---|
| Model | Evolution IV Revolver Hammer Kit |
| Material | Heat-treated steel (per manufacturer specs) |
| Compatibility | Smith & Wesson J, K, L, N frame revolvers (select models) |
| Finish | Black oxide |
| Weight | 0.8 oz (as installed) |
| Condition | New |
Key Features
- Pinned Sear & Stirrup Design — Why it matters: Eliminates side-to-side play and ensures consistent sear engagement, reducing trigger pull weight variation shot to shot.
- MIM Replacement — Why it matters: Swapping out the factory metal-injection-molded parts for machined steel improves durability and gives you a cleaner, more predictable break.
- DAO Conversion — Why it matters: Removes the single-action notch so every trigger pull is the same length and weight—perfect for competition or defensive use where consistency wins.
- Trigger Pull Reduction — Why it matters: Drops a stock 12+ lb pull down to 4.0 lbs with proper tuning, giving you a light, crisp pull that keeps your sights on target through the break.
- Drop-In Installation — Why it matters: No permanent modifications needed; you can install it yourself with basic gunsmithing tools and a few hours of patience.
Who It’s For
This kit is built for revolver shooters who want to push their wheelgun past factory limits without sending it to a custom shop. If you’re shooting USPSA, ICORE, or steel challenge, or if you carry a DAO revolver for self-defense and want a lighter, more repeatable trigger, the Evolution IV is your upgrade path. Early adopters and tech-forward shooters will appreciate the engineering that mirrors Performance Center internals at a fraction of the cost.
Pros & Cons
- Pro: Dramatic trigger pull reduction from 12+ lbs to 4.0 lbs with tuning.
- Pro: Machined steel construction outlasts MIM parts under heavy use.
- Pro: DAO conversion eliminates hammer bite and shortens lock time.
- Con: Not compatible with all Smith & Wesson frame sizes—double-check your model before ordering.
Comparison
| Feature | Apex Evolution IV Kit | Timney Alpha Competition Trigger | Geissele Super 3-Gun Trigger |
|---|---|---|---|
| Product Type | Revolver hammer kit (DAO) | Pistol drop-in trigger | AR-15 trigger |
| Pull Weight (tuned) | 4.0 lbs | 3.0–3.5 lbs | 3.5–4.0 lbs |
| Material | Heat-treated steel | Tool steel | Tool steel |
| Firearm Compatibility | S&W J, K, L, N frames | Glock Gen 3-5 | AR-15 |
| Price | $175 | $199 | $249 |
FAQ
How to polish revolver cylinder?
Start by removing the cylinder from the yoke. Use a fine-grit abrasive pad (600-800 grit) to polish the outer surface and chamber mouths in a circular motion. Clean with brake cleaner, then apply a light coat of gun oil. Avoid over-polishing the chamber mouths—removing too much metal can affect headspace. For the Evolution IV kit, keep polishing compounds away from the hammer and sear surfaces to prevent altering engagement.
Will this kit work with my Smith & Wesson 686?
Yes, the Evolution IV is compatible with the L-frame 686 in DAO configuration. Confirm your revolver has a standard hammer pivot pin (not a frame-mounted firing pin) before installation. Per Apex Tactical Specialties specs, the kit fits pre-MIM and MIM-era S&W frames with minor fitting.
Do I need professional gunsmithing to install this?
Not necessarily, but it helps. The kit is designed as a drop-in with basic tools (punch set, hammer, small screwdrivers). However, tuning the trigger to 4.0 lbs requires polishing engagement surfaces and checking sear depth. If you’re not comfortable with revolver disassembly, a qualified gunsmith can do it in under an hour.
What’s the difference between DAO and standard hammer?
DAO (Double Action Only) removes the single-action cocking notch. Every trigger pull is a full double-action stroke, giving you consistent trigger weight and length. This kit converts your revolver to DAO, eliminating the option to manually cock the hammer for a lighter single-action pull. It’s ideal for competition or defensive use where you want repeatable performance.
Can I use this in a revolver with a bobbed hammer?
Yes, the Evolution IV replaces the entire hammer assembly, including the spur. The included hammer is spurless (bobbed) by design, making it snag-free for concealed carry or holster work. It also reduces overall lock time compared to a factory hammer.
✔ Nationwide delivery (all 50 states)
✔ Ships 1-2 business days
✔ 30-day returns
✔ Secure checkout
Browse more in our Smith & Wesson Revolvers or Revolver Parts categories.
Last updated: April 2026
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