TandemKross recently released their Krossfire Bolt for the Ruger Mark IV and 22/45 pistols. It builds on their experience as providers of competition-ready aftermarket parts. They’ve taken all the internal bits that they’ve had for years, and stuffed them into a custom bolt. The result is a drop-in part which improves reliability and performance. And it doesn’t hurt that it looks great too. They sent me one for review, so here’s the full scoop.
Krossfire Bolt specs
Each bolt starts with a CNC machined bolt body. After that, they’re given either a flat black DLC (Diamond-like coating) finish, or gold TiN (titanium nitride). Both inhibit corrosion, but also reduce friction, which helps with reliability. TandemKross also redesigned the extractor plunger for easier disassembly and maintenance. A smaller, integrated version of their halo Charging Ring is attached at the rear. This contributes to the lower weight (138 grams) vs the OEM bolt with a halo (150 grams). Rings are available in black, gold, or red.
Inside the bolt are some familiar pieces. They include the Fire Starter Titanium Firing Pin, Eagle’s Talon Extractor, and their new Sentinel Guide Rod. I recently reviewed the Sentinel Guide Rod, and it’s a worthwhile upgrade on its own. Including it in the Krossfire Bolt complements the rest of the parts. Together, the bolt and components provide more reliable ignition, and smoother operation.
Installation
Swapping the bolt on a Ruger Mark IV is about as simple as can be. Drop the magazine, clear the chamber, rack the slide, put on the safety, and press the button at the rear. Then lift the upper off. Pull the old bolt out, install the Krossfire Bolt in its place, and reinstall the upper. Ruger makes the swap and subsequent cleanings super easy.
Range time with the Krossfire Bolt
Although I may have had some initial concerns about the smaller charging ring, my fat finger still fits inside. And there’s also enough width to just grab it and pull back to chamber a round. From there, my pistol ran as well as it usually does. During my testing of several hundred rounds, I didn’t have any failures to fire or failures to extract/eject.
Most of the time, we start out putting one round each on a series of targets at varying distances. Then everyone seems to want to double tap. From there, it’s mag dumps as fast as possible, trying to keep a can dancing or steel ringing. And this pistol gets shot fast. All testing was done with CCI standard velocity, and Aguila Super Extra along with a few handfuls of some old Blazer bulk ammo. So I’m actually a bit surprised at how reliable it was.
A Quick Cost Analysis
As a DIY guy, I usually wonder if I can reproduce the same results myself. Here’s the pricing breakdown for the parts included with the $219.99 Krossfire Bolt:
- Sentinel Guide Rod $19.99
- halo Charging Ring $49.99
- Fire Starter Titanium Firing Pin $26.99
- Eagle’s Talon Extractor $12.99
Rounded up four cents, that $110 in parts. A little research indicates that you can get a Ruger OEM bolt for $40 to $80 (that $80 guy is a ripoff). Coating is going to run $50 to $80. None of these numbers includes shipping. Best case scenario would be buying all the parts locally, and having coating done locally. That’s still $200, plus time spent driving around buying parts, dropping them off, etc. In other words, $219.99 looks like a very fair price to me*.
*The only flaw in this logic is obvious to most dedicated rimfire enthusiasts. Having a leftover OEM bolt lying around usually leads to buying a new lower, or at least another barrel.
A few words about my Mark IV
This has always been one of my favorite and most popular pistols. It’s accurate, and nearly unstoppable. Shooting it is fun, because it has excellent ergonomics, points naturally, and is easy to keep on target. Magazine dumps are quick and effortless. When it does start to have any issues, it’s because of the filthy bulk ammo we sometimes run through it. And a light cleaning resolves that in no time at all.
The upper is a standard Mark IV Lite upper, with a TandemKross Shadow Mount and Vortex Razor. At the loud end is a TandemKross Game Changer muzzle device. The lower is the original anodized red TandemKross Kraken (now Cthulhu). It’s got the Ultimate Trigger Kit, Cornerstone Safety, Striplin Thumb Rest, Bolt Keeper Extended Bolt Stop, along with the Tempest Grips and Magwell. All those custom parts, and no fitting or tuning required.
Conclusion
Friction is the enemy, and the Krossfire Bolt is your pistol’s new best friend. With reduced weight and friction, the bolt requires less energy to cycle. This translates into increased reliability. Lower velocity ammo or inconsistent ammo will still function with fewer stoppages. The firing pin ensures better ignition, and the extractor pulls empties out with authority. As cheesy as it may be to say it, the Krossfire Bolt really does make everything better.
Based on what I have seen on various enthusiast sites, the Ruger Mark IV series is valued for its performance and reliability, but also its aftermarket support. Owners love to tinker with them. And $220 for a new bolt doesn’t seem out of line. For competition, small game hunting, or shooting suppressed, this is the sort of upgrade that can yield meaningful benefits.
As always, I’d like to thank TandemKross for allowing me to review yet another cool upgrade. If you’d like to read more, or get your own, head over to the TandemKross website.
Thoughts? Opinions? Questions? Feel free to share below.
This seems like a very nice upgrade to an already awesome platform. I will definitely be purchasing one for my plinker ASAP.
A wise choice!
Thats a slick looking gun, might have to build a Tandemkross gun someday.