Lee Precision’s Lead Hardness Test Kit

Lee Precision’s Lead Hardness Test Kit

In this article we’ll be taking a look at Lee Precision’s Lead Hardness Test Kit.  The first thing people usually ask about these is why you’d ever want to test the hardness of cast bullets to begin with. The short answer is that bullet hardness plays an important role in accuracy as well as keeping your barrel clean.  A bullet that’s too soft will leave heavy lead deposits inside your guns rifling grooves, reducing accuracy, and requiring substantial cleaning.  Conversely bullets that are too hard won’t obturate properly when fired, failing to fully engage the barrel’s rifling, and allowing propellant gases to escape around them.  Both scenarios are frustrating, particularly when you’re loading your own ammunition to try and surpass the accuracy of factory cartridges.

Opinions differ on the ideal hardness for cast bullets, but I prefer to use a mid-range alloy made from wheel-weights, and quenched in water.  This yields a bullet of roughly 18 on the Brinell hardness scale and that’s I’ll be aiming for when describing the testing process using some cast bullets in this article.

When I first saw the Lee Lead Hardness Tester I have to admit, I was skeptical.  It’s easily the cheapest option on the market, and I didn’t have much faith in their visual measurement system vs the dial-gauges favored by competitors.  As it turns out, while researching other options I came across a fantastic article written by the Los Angeles Silhouette Club on this very subject.  LASC conducted dozens of tests using multiple testers from six different brands, and compared their results to lab-verified alloys– and guess what?  Their findings concluded “The Lee tester appeared to produce the most readings that were both consistent and closest to the actual laboratory results.”

I was so impressed by the depth and detail of their testing that I ordered the Lee model the very next day, and I’m glad I did.

Kit & Installation

So what exactly do you get for your money?  The tester comes in one of Lee’s standard plastic cases complete with a ball-indenter, v-block, compact 20x microscope, and a simple set of instructions.

Installation is a snap; the operator begins by sliding the included v-block into the ram of a single stage press, then threads the indenter into the top like any other reloading die.  That’s it.

With the kit installed, the only thing left to do is file one side of each test bullet to provide a broad, flat surface for the indenter, and subsequent reading.

Operation

The operator begins by placing a bullet on the v-block, and raising the ram until the indenter applies just enough force for the internal spring rod to sit perfectly flush with the tool body.  The user needs to hold it steadily in this position for thirty seconds; this ensures a constant amount of known pressure is applied for a consistent period of time.  These two details are critical to obtaining a reliable, accurate and repeatable reading, so make sure you follow them to the T.

Once thirty seconds have elapsed, the operator lowers the ram and removes the bullet.  This will reveal a clear and prominent indentation in the middle of the test surface.

From here the user will take their measurements.  With the included 20x microscope, the operator places the objective lens (the one furthest from your eye) directly above the indentation and looks through the ocular lens (the one closest to your eye) to obtain a reading. This is more difficult than it sounds, as at times the angle of the microscope’s opening can be less than ideal depending on the position of your light source.  Likewise, the microscope’s ocular lens is quite small, making if challenging for some folks to line up properly, particularly if you have glasses.  When looking through the microscope, the user simply lines up the divisions with opposite ends of the indentation, counting the number it takes cross the diameter.  Each division line equates to two thousands of an inch (0.002″) and should be counted as such for the purposes of calculation.

When testing bullets, I strongly recommend using at least five from each sample, and averaging the results.  This will help to eliminate any oddball readings and ensure a better overall estimating of the hardness of an entire batch.  When testing a handful of .45ACP projectiles, I obtained an average of 0.054″; referring to Lee’s included scale that translates to a reading of 17.9BHN, nearly bang-on the 18BHN I was shooting for.

In addition to the BHN table, Lee has also included some other useful information in the measurement chart.  Each BHN rating also conveniently lists the maximum recommended pressure (in PSI) at which these rounds can fired without resulting in barrel leading using most firearms.  This is an invaluable tool when gauging the suitability of a new batch of bullets for use with a specific load.  It’s worth noting; while modern reloading data generally lists pressures in PSI (pounds per square inch), some older data and manuals will use CUP (copper units of pressure) or LUP (lead units of pressure).  These are two totally different units of measurement and are NOT interchangeable with PSI.  When calculating max pressure for a particular bullet hardness, make sure you’re comparing apples to apples.

Summary

So what’s the verdict on Lee Precision’s Lead Hardness Tester?  There’s a lot to like here; for starters it’s the cheapest product on the market which is obviously a big plus.  It’s also well made; the indenter is all steel, the microscope has a metal body and glass lenses, and quality matters to me.  The most important feature though, is that it measures well.  Thanks to LASC’s independent testing, we know this is the most accurate and reliable product available.

As much as I like this tool it’s not perfect, although my gripes here are pretty minimal.  I respect the fact that Lee’s trying to keep their prices down using universal packaging as much as they can, but the fact that the v-block doesn’t actually fit in the recess for it is disappointing.  More annoying still is the fact that the microscope is too long to fit in any of the grooves or slots, meaning you have to just sort of let it flop diagonally.  That’s a rather poor way to treat any optic in my opinion.  My biggest complaint though is the actual taking of readings.  Holding the microscope and bullet steady can be challenging, especially when everything’s magnified 20 times.  I feel like a simple plastic tripod or holder of some sort would have made the mic much easier to use, and likely lead to more accurate readings.  Hopefully Lee updates this kit with something to that effect in the future.

Those issues aside though I do think this is a solid product.  One of the reasons I keep coming back to Lee is their ability to manufacturer tools that leverage my existing equipment and space, and this is another fine example of that same innovation.  Likewise as accuracy is my top priority I’m certainly pleased that the best functioning tool also happens to be the cheapest.

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