Like the rest of the world, I have been feeling the effects of ammunition prices. I don’t train as much as I want because I hate throwing unreasonable amounts of money downrange. However, shooting is a perishable skill, and consistent practice is necessary to maintain any level of proficiency. Since the ammo crunch, I’ve decided to formulate a plan to reduce the cost of practice. 
 

The Plan

Step one of my plan was to acquire a .22 LR slide for my primary range gun, the Shadow System MR920 Elite with a Holosun 507c red-dot optic. To convert my 9mm Shadow Systems gun into a .22 LR training pistol, I need a conversion kit that replaces the slide, barrel, and magazine. Luckily, the MR920 is compatible with most Glock 19 Gen 3 parts, so a .22 LR conversion kit for the G19 would work on my Shadow Systems frame.  

First I had to decide on a conversion kit. The two most popular brands are Advantage Arms and Tactical Solutions. Both companies have good reputations. I choose the Tactical Solutions unit because I’ve had good experiences with their products in the past. Also, the slide weight for their conversion more closely replicates a centerfire slide, and it’s offered with a threaded barrel. I have suppressors I plan to use with this gun, so that kind of sealed the deal.
 

I wanted to go with a conversion kit as opposed to a completely new firearm, such as the Glock 44, Taurus TX22, Ruger 22/45, or some other .22 LR pistol because I wanted a gun that fit my existing holsters and used my existing Shadow Systems match trigger. But getting a dedicated .22 LR pistol would not be a bad decision either. The big problem, however, was replicating the red-dot sight on the conversion slide.  

Getting the Red Dot to Work

A few years ago, I took a Modern Samurai Project red-dot course with Scott Jedlinski. It changed my view on pistol mounted optics, and now I have red dots on nearly all of my guns. Pistol red dots are truly the future. They allow for faster, more accurate shots at longer distances in more varied light conditions when compared to iron sights. This is the primary reason optics and red-dot sights are standard on military rifles now. Mounting them on pistols is the next logical step.  

Some companies are still catching up with the trend, and no rimfire pistol conversion uppers are cut for optics yet. Therefore, I had to figure out a solution on my own.  

The best way to mount an optic to a slide is to have the slide custom cut to fit the specific optic. That said, I sent the Tactical Solutions slide and a Holosun 507c to C&H Precision, one of the top pistol optics mounting outfits, and had numerous talks with them about my build. Ultimately, they said they were not able to cut the slide because there was not enough material. 
 

The next best solution was buying a red-dot mounting plate that fits into the rear sight dovetail. I was able to put this together, but I found that it would not run reliably. Most .22 LR pistols work on the direct blowback system. The pistol remained locked based on the weight of the slide and the recoil spring pressure. It seemed as though the additional weight of the mount and Holosun optic increased the mass of the slide so much that it caused malfunctions in the cycling. I needed to cut some weight.

According to the Holosun website, the 507c weighs 1.5 ounces. The lightest red dot I could find was the Sig Sauer RomeoZero at 0.4 ounces. The RomeoZero achieves this by being made entirely of polymer, including the viewing window. With this in mind, I needed to find a way to test if the RomeoZero would give me the same malfunctions. Lucky for me, Lakeline makes a Glock dovetail plate that fits the footprint of the Sig RomeoZero.
 

The End Result

Installation was easy and only required a punch and some Loctite. To date, this trainer has run very reliably with most high-velocity ammo I've tried. Tactical Solutions recommends only high-velocity ammo for their kit. It even locks back on the last round. I’ve found some standard velocity also functions similarly. Accuracy has also been excellent, with 2-inch groups at 25 yards being normal.

One thing to note, the Tactical Solutions kit does not work with the Apex Glock trigger kit. I happen to be testing that trigger kit, and the trigger would not reset with the conversion kit. But the stock Shadow Systems trigger, which is excellent, had no problems. If you have an aftermarket trigger, you might want to double check to see if the conversion kit will be compatible. 
 

What Kind of Training?

Now, you may ask, what kind of training do I do with this .22 LR pistol? Of course, there is almost no recoil, so I can't use it for recoil control and multiple-shot drills. But it excels at drawing practice from my existing holsters. I can do all kinds of draws including from concealment, range-belt strong side, and unconventional positions such as seated. And it only cost pennies per shot. In addition, I practice low-ready first shots and even single-shot transitions, where I simulate the first shot and practice transitions to a second target.  

It's also fun to just shoot matches with this gun. There are a bunch of my local pistol competitions like IDPA and Outlaw Steel that now allow rimfire pistols because centerfire ammo is so expensive. You could also shoot at regular rimfire pistol matches like Steel Challenge and get more practice with your carry-style Glock, and don’t discount the fact that it is fun just plinking with a .22 pistol. With a suppressor, it’s so quiet that I could shoot in my back yard. The possibilities are numerous with this fun conversion.  
 

Conclusion and Final Cost

Final cost breakdown for this build was $405 for the conversion, $36 for magazines, $219 for the RomeoZero, and $32 for the mounting plate. These are MSRP prices. You could probably find some of these parts for less if you look for deals or wait for sales. The Advantage Arms kit is less expensive at around $250. 

While not exactly a cheap endeavor, it does save in the long run. Basically, the cost of another pistol or two to three cases of new brand-name 9mm ammo. Up front, it is a considerable amount, but if you look at the cost over time ($0.10/round for high-velocity .22 LR vs. $0.50 /round for 9mm) you will recoup the cost in about two cases of ammunition.