Welcome to another deep dive into the world of rimfire firearms. While most enthusiasts are well-acquainted with the ubiquitous Ruger 10/22 or the modern KelTec CMR-30, there exists a subset of firearms that often fly under the radar. Today, we are focusing on the Excel Arms MR-22 Accelerator rifle, a unique semi-automatic platform chambered in .22 WMR (Winchester Magnum Rimfire). Despite its distinctive design and interesting history, it remains a somewhat forgotten piece of rimfire engineering that still finds its way onto the market today.
What is the Excel Arms MR-22 Accelerator?
The Excel Arms MR-22, along with its pistol counterpart, the MP-22, represents a rare breed of semi-automatic firearms chambered in .22 Magnum. While the pistol version shares a visual silhouette with the Smith & Wesson Victory, the MR-22 Accelerator rifle takes a different approach. Its aesthetics are more reminiscent of the Beretta Cx4 Storm, featuring a robust synthetic one-piece stock where the magazine is uniquely housed within the grip.
Key Specifications and Features
Over the years, the MR-22 has been released in several configurations to suit different shooter preferences. Standard features typically included:
- Barrel: An 18-inch stainless steel fluted bull barrel.
- Weight: A substantial 8 pounds, giving it a very stable, “big rifle” feel.
- Capacity: Usually shipped with two 9-round magazines.
- Versatility: Available in flat-top versions with either Picatinny or Weaver rails, and some models even featured removable carry handles.
Interestingly, Excel Arms also produced a version of this platform in 5.7x28mm, further cementing its reputation for catering to niche rimfire and small-caliber enthusiasts.
Market Value and Availability
When it first hit the market, the MSRP for a base model Excel Arms MR-22 Accelerator rifle started at approximately $512. However, for those who wanted high-end optics, specialized carry handles, or other factory accessories, the price could easily climb toward the $1000 mark.
In the current market, these rifles have become somewhat of a collector’s item. If you can find them in stock at online retailers, they typically retail for about $650. On various auction sites, starting bids often hover around this same price point, reflecting its status as a specialized firearm rather than a mass-market staple.
Performance: Reliability and Accuracy
The reputation of the MR-22 is a bit of a mixed bag, largely depending on the era of production and the owner’s attention to detail.
Reliability Challenges
Reliability is often the primary concern with semi-auto .22 WMR rifles. Early users in the 2010s generally reported positive experiences, though extraction issues were a common theme—a challenge that plagues many rimfire platforms.
A notable quirk of the MR-22 is its break-in period. The official manual specifies a 200-round break-in, yet many rifles found on the secondary market are listed with fewer than 100 rounds fired. This suggests many owners may not have pushed through the initial “stiff” phase of the action. Furthermore, reliability is heavily dependent on the magazine loading tool. Because .22 WMR is a rimmed cartridge, improper stacking leads to feeding failures. Using the factory tool ensures the rims are oriented correctly for smooth cycling.
Accuracy Potential
On the flip side, the accuracy of the MR-22 is frequently praised. Like most rimfire rifles, it is “picky” about its diet. However, once owners find the specific brand and weight of ammunition the rifle likes, the results are impressive. Reports of 1/3-inch groups at 50 yards are not uncommon, making it a potentially devastating tool for small game hunting or precision plinking.
Is the MR-22 Worth Adding to Your Collection?
In the modern landscape, the Excel Arms MR-22 Accelerator rifle faces stiff competition. The KelTec CMR-30 offers a more modern, lightweight alternative that is generally easier to find and support.
Because the MR-22 has virtually zero aftermarket support and a somewhat temperamental reputation regarding its cycling, it may not be the ideal choice for a primary “workhorse” rifle. However, for the die-hard collector or the rimfire enthusiast who enjoys tinkering with unique designs, the MR-22 offers a heavy-duty, stainless-steel build that is increasingly rare in today’s world of polymer-heavy firearms.
Whether you see it as an obscure masterpiece or a finicky relic, the Accelerator remains a fascinating chapter in the ongoing evolution of .22 Magnum semi-autos.