Lyman MSR Ammo Checker Block Review

Let’s Talk About Lyman MSR Ammo Checker Block

The Lyman MSR Ammo Checker Block is a precisely machined tool designed to quickly verify the dimensions of rifle ammunition, ensuring smooth chambering in modern sporting rifles. Made by Lyman, it’s aimed at reloaders and shooters who want to avoid malfunctions caused by out-of-spec ammunition. I have been reloading for over a decade, and I’ve seen firsthand the frustration of a match being ruined by a single round that won’t chamber.

I decided to purchase the Lyman MSR Ammo Checker Block because I’ve recently started reloading for multiple AR-platform calibers, and I wanted a fast, reliable way to check my rounds after sizing and seating. I was seeking peace of mind and reduced risk of malfunctions at the range or, more importantly, during competition. The compact size and claimed compatibility with multiple calibers appealed to me.

Upon unboxing, my initial impression was positive. The black anodized aluminum felt solid and well-made, and the CNC machining appeared precise. It was lightweight but had a reassuring heft. I was eager to see how it compared to using my case gauge, a process I’ve always found to be cumbersome.

I considered other ammo checkers from RCBS and Dillon Precision, but I opted for the Lyman due to its multi-caliber compatibility and seemingly straightforward design. It appeared to offer the most comprehensive solution for my reloading needs. Initially, I was excited to add this tool to my reloading bench, envisioning a streamlined process for ensuring my ammunition would perform flawlessly.

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Real-World Testing: Putting Lyman MSR Ammo Checker Block to the Test

First Use Experience

I first tested the Lyman MSR Ammo Checker Block at my reloading bench while preparing rounds for an upcoming 3-gun match. I checked a batch of .223/5.56 rounds, alongside a small batch of .300 AAC Blackout ammunition. Each round was individually inserted into the corresponding chamber of the block to check for proper fit.

The .223/5.56 rounds seemed to fit okay, but the .300 AAC Blackout had some that didn’t seat fully. I wasn’t sure if I was using the tool correctly. It was surprisingly difficult to tell if the rounds were truly “in-spec” based solely on the checker block.

Extended Use & Reliability

After several weeks of consistent use, I began to question the Lyman MSR Ammo Checker Block’s reliability. I had multiple instances where rounds that passed the checker block failed to chamber correctly in my rifles, particularly with 6.5 Grendel and .450 Bushmaster. This defeats the entire purpose of the tool, as it is meant to guarantee smooth chambering. The black anodized finish has held up well, showing no significant wear, but its accuracy is the real problem.

Cleaning is simple – a quick wipe with a cloth is all that’s required to remove any debris. However, the tool’s inconsistent results undermined my confidence in my ammunition and ultimately made me revert back to using individual case gauges for each caliber. The Lyman MSR Ammo Checker Block underperformed compared to my expectations and the performance of individual case gauges.

Breaking Down the Features of Lyman MSR Ammo Checker Block

Specifications

The Lyman MSR Ammo Checker Block is machined from 6061 T6 aircraft grade aluminum with a black anodized finish, weighing approximately 3 oz. It is designed to check the following calibers: .223/5.56, 6.5 Grendel, 6.8 Rem SPC, 7.62×39, .300 AAC Blackout, .450 Bushmaster, .458 SOCOM, and .50 Beowulf. The Lyman MSR Ammo Checker Block uses CNC machining to create chambers that meet minimum SAAMI specifications, which should ensure reliable chambering in MSR platforms.

These specifications should translate to a durable and precise tool. The multiple caliber options are a significant benefit for reloaders who work with a variety of AR-platform rifles, but ultimately the execution is lacking.

Performance & Functionality

In theory, the Lyman MSR Ammo Checker Block should quickly and accurately confirm whether reloaded or factory ammunition will chamber smoothly in a firearm. However, in practice, its performance is inconsistent. Some rounds that pass the check still fail to chamber, while others that feel tight in the checker block chamber perfectly fine.

The main strength of the Lyman MSR Ammo Checker Block is its multi-caliber compatibility, but its primary weakness is the lack of consistent accuracy. It does not always meet expectations. The Lyman MSR Ammo Checker Block needs significant improvement to provide reliable and trustworthy results.

Design & Ergonomics

The Lyman MSR Ammo Checker Block is compact and lightweight. Its aluminum construction feels durable, but the small size can make it slightly awkward to handle, especially when checking larger calibers like .450 Bushmaster or .50 Beowulf. There is minimal learning curve. You just drop the rounds into the appropriate holes, but knowing if they are really in spec is a different story.

Durability & Maintenance

The Lyman MSR Ammo Checker Block is constructed from durable aluminum. It should last a lifetime with proper care. Maintenance is simple: a quick wipe with a clean cloth to remove any residue or debris.

Accessories and Customization Options

The Lyman MSR Ammo Checker Block does not come with any additional accessories, nor does it offer any customization options. It’s a simple, standalone tool designed for a specific purpose. Compatibility with accessories is not applicable in this case.

Pros and Cons of Lyman MSR Ammo Checker Block

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Who Should Buy Lyman MSR Ammo Checker Block?

The Lyman MSR Ammo Checker Block is potentially suitable for reloaders who load for a wide variety of AR platform calibers and are looking for a quick way to check ammunition dimensions if they are willing to double-check its results. It’s possibly suitable for casual shooters. They may find it helpful for quickly checking factory-loaded ammunition if they accept the risk of occasional malfunctions.

However, competitive shooters, serious reloaders seeking absolute reliability, or anyone who values consistent accuracy should skip this product. A set of individual case gauges will provide far more reliable results.

A must-have modification would be an improvement to the chamber dimensions to ensure consistently accurate readings. A secondary method of verification is recommended to ensure proper chambering.

Conclusion on Lyman MSR Ammo Checker Block

The Lyman MSR Ammo Checker Block promises a quick and easy way to verify the dimensions of your ammunition. However, in my experience, it fails to deliver consistent and reliable results. While the multi-caliber compatibility and durable construction are appealing, the checker block’s inconsistent accuracy undermines its entire purpose.

At $63.49, the price is not justified given its unreliable performance. I would not personally recommend the Lyman MSR Ammo Checker Block. It is an unreliable product.

If you’re serious about ensuring your ammunition chambers correctly, invest in individual case gauges for each caliber you reload. You’ll save yourself the frustration of malfunctions and wasted time at the range. Don’t gamble with your ammunition – invest in reliable tools that deliver consistent results.