Hello and welcome back to another edition of The Rimfire Report! A couple of months back we took a look at the Maddmacs Precision Tactical MK4 Carbine series of rifles designed by Competition Shooter Wade Reed. The MK4 Carbine makes use of largely the same design as the Ruger MK4 pistol by virtue of it using virtually all of the same parts, just slightly altered to make the firearm a rifle rather than a pistol. The designer of the MK4 Carbine, Mr. Wade Reed recently reached out to me asking if I would be interested in taking a closer look at one of these and trying one out for myself. I happily accepted the offer to try one out and have since then had a fair amount of range time with it including two full Steel Challenge competitions that gave me a good bit of insight into the pros and cons of this lightweight platform.

More Rimfire Report @ TFB:

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• The Rimfire Report: Overdue SIG P322 Maintenance
• The Rimfire Report: The Stevens Pocket Rifle (Bicycle Rifle)

The Rimfire Report: Steel Challenge with the MK4 Carbine

The MK4 Carbine actually comes in 4 different styles from Maddmacs Precision Tactical. These include the standard steel 16″ bull barrel version, MK4 Carbine SRB (Suppressor Ready Barrel), MK4 Carbine CF, and the MK4 Carbine Bantam. Wade opted to send me over one of the CF versions which costs $1,199.95 and comes with an upper assembly that weighs only 21 ounces and still allows you to switch from rifle to pistol with a simple push of a button (provided you’re using a stock MK4 frame from Ruger).

Ruger MKIV (top) and the MK4 Carbine (bottom)

Like all of the different versions of the carbine, the CF version only comes with the receiver, threaded barrel, and bolt meaning you’ll still need to provide your own buffer tube, optic, and desired rail type to complete the build. Wade was kind enough to send along a pre-mounted C-MORE slide ride interface. I provided my own Tandemized frame, C-MORE Optic, MIL-SPEC Buffer tube, and a Magpul SL stock.

The assembly process is pretty straightforward and all that is really needed is for you to thread on the buffer tube which is held in place by a single set screw. The fitment between the carbine upper and the TANDEMKROSS lower is extremely tight and the Tandemized frame only makes this fitment tighter via its tensioning screw. However, despite my being absolutely in love with my TANDEMKROSS Kraken frame, there are quite a few drawbacks that it has in its current configuration that we will talk about here in a minute. For now, the overall fit and finish of the MK4 Carbine CF are superb and my first few initial range sessions with it were great with the carbine operating flawlessly with a wide variety of ammunition including CCI Standard, Federal Subsonic, CCI Mini-Mags, Norma TAC-22, and some bulk Herters 22LR. I shot 5 subsequent groups with 5 different magazines and had some pretty good results at 25 yards after an initial zeroing with CCI Mini-Mags.

Steel Challenge with the MK4 Carbine

When it comes to rimfire Steel Challenge firearms you’ll see a lot more lightweight designs used by high-level Grand Masters. The MK4 Carbine CF perfectly embraces this mentality and mine in its current configuration barely weighs 3lbs. The issue here is that undisciplined shooters (like myself) often will overestimate target transitions with lighter rifles and pistols and this can cause a lot of misses. I’m not saying that the lightweight nature of the carbine is anything to scoff at, it’s definitely faster but there is a pretty steep learning curve to getting the basically non-existent rifle under control for quick, accurate shots on steel challenge stages.

All ammunition types I tried with the MK4 Carbine worked well and grouped well out of the 16″ Carbon Fiber barrel. Each group was shot at 25 yards using a 2 MOA C-MORE red dot optic. The bottom right group was shot with CCI Standard Velocity.

During the competition, I was pleased with how quickly I was able to transition from target to target. However, there were some issues with my initial configuration of the carbine which largely surrounded the extra bits and pieces attached to the Kraken frame that, while great for the MK4 pistol, do absolutely nothing for the carbine and in some cases actually got in the way or caused issues on the range. One was the Kraken lower refusing to reset the trigger and the other had to do with the oversized safety selector on the Kraken. The placement of the charging handle for the carbine meant that I couldn’t use the extended safety lever as a thumb rest like I typically would – doing this simply resulted in the charging handle (which is reversible) smacking into my thumb when firing. While you can reverse the charging handle, I have both of my steel challenge carbines set up the same way with the charging handle on the left so I’d sooner remove the extended thumb safety than swap which side the charging handle is on – but the option is there for those who want to or need to.

The “gas pedal” thumb rest for your support hand is pretty much useless when used with the carbine. The barrel doesn’t really heat up after a high volume of fire.

The safety thumb rest can’t be used with the charging handle on the left-hand side which is unfortunate but not really a big deal since you have better stability through the use of your support hand and the rifle’s barrel.

During the competition, I found that my trigger would not reset consistently. After getting home from the range, I discovered that the internals of the Kraken frame was so fouled it was causing issues with reliability. I have since cleaned it and the trigger has returned to functioning normally.  Further proof that functionality issues weren’t caused by the upper comes from my curiosity about swapping out the Kraken frame for my stock Ruger MKIV frame – in this configuration, the carbine went back to functioning like the freshly cleaned Kraken frame/carbine combination. For those that compete, this should come as no surprise as competition guns tend to be somewhat sensitive when it comes to cleaning schedules and I tend to be a bit lazy when it comes to cleaning my guns. While I don’t doubt that the MK4 Carbine works better with CCI Mini-Mags, during my entire testing phase, the firearm seemed indifferent to which type of ammunition it was using. In any case, keep your guns clean – they’ll work better.

The stock Ruger MKIV frame makes for a quick swap between the pistol and carbine configurations – no tax stamp needed!

Aftermarket magazine components greatly reduced the number of function issues that the Kraken lower caused with the carbine receiver.

Pictured is the only type of malfunction I encountered with the round getting caught on the slightly longer feed ramp of the MK4 Carbine and thus not being able to be stripped out of the magazine. Cleaning the Kraken frame, and the magazines seemed to fix this issue.

Final Thoughts

I really like what Wade Reed and MaddMacs Precision Tactical have done with the MK4 Carbine series. On the competition side of things, the carbine definitely feels much faster to shoot and the inline placement of the buffer tube and stock means that it tends to reduce muzzle climb making for a very light and easy-to-control recoil impulse making for faster makeup shots after a missed target.

Since the MK4 Carbine starts off as such a lightweight package, you could theoretically still have a super lightweight backpacking/hiking rifle, even after you add lots of heavy components like a beefier enclosed emitter optic, sling, and even a heavier or more comfortable stock, the possibilities are virtually endless. However, if I were to take the MK4 Carbine down the route of a backpacking rifle, I’d probably opt to use the stock polymer Ruger MKIV frame instead of the Kraken to make cleaning in the field easier and to reduce the risk of issues caused by environmental exposure.

If you’re interested in purchasing any of the MK4 Carbines, Wade currently makes them in pretty small batches and sells them on a first-come, first-serve basis. If you’re interested in picking up one for your own personal collection you can reach out to him for ordering info at (231) 645-4647. I’d like to hear your thoughts on the MK4 Carbine. Is Wade’s design what you might want for a competition-oriented 22LR rifle or even a lightweight backpacking rifle? Let us know your thoughts down in the comments below and as always thank you for stopping by to read The Rimfie Report we’ll see you all next week!