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Upgrading the Ruger Mk4 22/45 Lite

Recently, Jared and I have started shooting Steel Challenge competitions again. I am not unfamiliar to the steel challenge game. I used to shoot a steel challenge match almost weekly back in the day, and loved shooting it. It’s a great competition that is fun and easy to get into for the newer and younger shooters, and challenging enough for the more experience shooters to race down to that last tenth of a second. My favorite division in Steel Challenge to shoot is the rimfire open class…which is one of the hardest to compete in because of how blazingly fast these guys shoot these guns.

I have an older Ruger MkIII 22/45 that I built to include with a trigger job, red dot, and compensator on it…way before the Ruger MkIV 22/45 was ever even imagined. Last week I took it out to the last steel challenge match, and ended up getting second place with it. I did notice, however, that it was very heavy; and that my transition split times could decrease if I could get some weight off of the gun. On my MkIII that isn’t really an option…so of course I felt like I needed a brand new platform to start with…any excuse for a new gun right?! It was time for an upgrade.

I knew I was going to build one of the new Ruger MkIV 22/45 LITE pistols…but was having a hard time deciding which one specifically I wanted because there are so many receiver cuts and color combos that we had that it was an impossible choice. Emily and I narrowed it down to our favorite two…but still couldn’t decide so it was time to bring in the deciding factor. We invited Colt, our 8 year old into the office and asked him which one he liked the best out of our two. He was the ultimate deciding factor in selecting the beautiful red anodized MkIV that would become my next, new, open race rimfire pistol.

Let the games begin…

I needed to then start sourcing a bunch of parts for it to begin to take what is a great platform, and make it even better. There are a few big names in the rimfire pistol world…with 2 of those being Volquartsen, and Tandemkross. I knew that I wanted the Tandemkross “Game Changer Pro” compensator on the end to start with, and began filling my shopping cart. I had a Volquartsen trigger kit in my Ruger Mk3, and it is legitimately the absolute best trigger I have ever felt. Jared had also recently built up a 22/45 and put in the Volquartsen “accurizing kit” in his too…so I figured I’d change it up and try out the Tandemkross ultimate trigger kit since I’d never had a chance to play with one of those before.

The basic Ruger MkIV grips are ok; but just a basic plain rubber grip…so of course we had to change those as well. I have used the LOK bogies before on my CZ Shadow 2, and knew that they had an amazing feel. Jared also used a set of LOK bogie grips on his 22/45 as well…so it was back to the shopping cart I went and ordered a set of gray and black bogies that look amazing, feel even better, and fit amazing. It was the perfect pairing for the grip.

Last problem to solve for the new open race gun was the optics to sit on top. I decided to go with the Swampfox Justice and picatinny mount to sit on top of the rail. It has a huge 27mm window, and good, dependable red dot that would serve me well for the steel challenge competition that I was planning on using it for.

Now that I had all of the pieces of the puzzle, it was time to start disassembling the MkIV and see what springs I could send into orbit to accompany the international space station. Taking the top end off the Ruger MkIV 22/45 LITE is a breeze, and huge upgrade compared to the last generation MkIII pistols…of which you need a doctorate in theoretical physics to be able to field strip. The Ruger MkIV has a big button on the back that you press, and the whole top end rotates up and off. I set the top end to the side and began work getting the little pieces out of the lower end that I was going to be replacing. I started by removing the trigger, which was a small retainer spring that just needed to be pressed out of the way, while also simultaneously pressing out the trigger pin. The entire assembly then just rotates up and outwards…easy enough. Next I removed the safety…which then releases everything else in the lower into a small neat (I meant launches dramatically under spring tension) little pile on the table…of which I had no idea how it all came back out of there. Last cam the sear pin which releases the sear and spring which dropped out the bottom of the grip easy enough.

It was time to begin putting the puzzle back together.

I started with the new sear and spring out of the Tandemkross “Blast pack”. With an extra set of hands from Emily, it dropped into place very easily, and built too much confidence for the next part to come. It was all downhill from there after I launched every other spring and detent into the abyss a minimum of 3 times trying to get everything lined up in the correct order. Eventually it all came together after a few different runs across the carpet looking for dropped parts, and the gun was finally reassembled.

The Tandemkross trigger has a huge wide flat face, with a lot of aggressive texture on it that I absolutely love. It has an amazing feel to it, and great feedback. It also has set screws for pre-travel and over-travel adjustment. The trigger feels much better as well with the new hammer, sear, and removal of the magazine disconnect. I would estimate it at around 2.5lbs. There is a slight amount of creep across the sear and hammer, but not terrible. It definitely won’t be noticed when shooting sub .20 splits at a steel challenge. The over travel adjusts to right past the breaking point which is nice, though there is a little more pre-travel in the trigger in order for the trigger to reset properly. With the geometry of the 22/45 pistols, however, it is a very nice trigger, and my only real complaint would be the small amount of creep on the sear. I feel like that creep will eventually smooth itself out over time of shooting and breaking it in…or a bit of flitz and a polish could smooth it out a touch faster if I ever get bored and feel like exploding the internals of my pistol again. Overall, though the Tandemkross trigger kit is a great improvement over the stock internals.

A tale of two Ruger’s…

The end result was a brand new, smokin red hot, Ruger MkIV 22/45 LITE that was a whopping 11.6 oz lighter than my last generation MkIII…which is a HUGE difference in a gun that small, and while trying to shoot fast transitions between different targets. The trigger isn’t quite as good as my Volquartsen trigger in my MKIII…but that has some slightly different internals than the MKIV, and the MKIII has been polished to perfection. On a drop in trigger kit for the MkIV I really can’t complain, and honestly love the feel of it as well. The difficulty of install could be an issue for some if you’re not used to taking down guns to their atomic level. It doesn’t require any special tools, but there are a lot of small springs and detents that can go awry if not careful. Overall I would rate the difficulty level of the install at a 5 out of 10. If you have good mechanical knowledge and like to tinker with things…it can definitely be done in an evening with a small pair of tweezers, a punch, and an allen key…with only minor cussing and regret of life choices.

I can’t wait to get it out to the range and see what kind of difference that dropping this extra weight can do to my times at the split challenge.



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