On “I Tried It For Science Saturday” I will try something new – so you don’t have to try it. Let’s just say I did it for science! I likely won’t use the scientific method, develop a hypothesis, or write up a formal theory but I will tell you what I think. Close enough, right?
Before I get started, I want to give a shout out to Mr. SiL who did much of the sciency bits for this post and provided the technical language. Thanks, Mr. SiL, you make me seem smarter!
Why do you need a Ballistic Chronograph?
So, Mr. SiL loves science and tech and shooting about as much as I love beauty and shooting. Over a year ago he pre-ordered a LabRadar chronograph in order to measure the speed of some rounds we were reloading. For those unfamiliar, reloading is a pretty big thing for serious shooters of all types. Turns out that if you have the time and patience, you can make your own ammo at home tailored to your exact needs — at a much lower cost for the same quality.
A full discussion of reloading is well beyond a “For Science Saturday” post, and likely the scope of this blog (but let me know in the comments if you beg to differ!), but suffice to say, with a little elbow grease and some reloading equipment Mr. SiL and I can put together some rounds we like for competition for about 10 cents a round, where a comparable factory round would be about 30 cents.
Of course, when you are reloading, besides the obvious need to be very careful, attentive, and always err on the side of caution, you are going to want to check your work! This can be especially important if you are trying to keep your bullets traveling below the speed of sound, which can be important for certain applications. For example, we both like slower, sub-sonic bullets for pistol shooting as they tend to have a less “snappy” recoil and are notably quieter. If you have ears as sensitive as mine, this is important when using an indoor or enclosed range.
Why the LabRadar Ballistic Chronograph?
We initially checked our speed using a traditional chronograph, similar to the one pictured below. The range procedure typically involves setting up the chronograph on a tripod, in front of where you are going to shoot, and shooting through the two sets of “V”s. There are sensors at the bottom of the “V”s that detect the shadow of the bullet passing over, and from there measure the speed.
There are a couple of drawbacks here. First, on a cloudy day or under a bunker, you may have to shoot closer to the sensors to pick up the shot. This is a recipe for shooting just a touch too low and turning your investment into scrap and possibly creating a dangerous ricochet. Second, you are only getting the speed AT the chronograph. This is fine for a lot of applications, but what about long range shooters that want to verify the speed of a bullet at 100yds downrange? The only option there is setting up multiple chronographs and threading the needle or doing multiple sets of tests.
In the last couple of years several manufacturers released products to get around the limitations of traditional ballistic chronographs. In this post we’ll focus on the LabRadar, which solves this problem by using Doppler Radar. This is the same type of technology that police radar guns use to measure the speed of motorists and the military uses to track planes, missiles, and artillery shells. I’m not gonna lie, it’s super fancy.
What are we testing?
We decided to test a couple of different 9mm rounds with the LabRadar Chronograph. First, what I would call some practice-quality snappy rounds. These Blazer rounds have been very reliable for us but have a bit more snap and flash than we’d like when trying to shoot quickly when tenths of seconds matter. The second set of rounds we’ll test is from an older batch of reloads we formulated to shoot a slower and heavier bullet at sub-sonic velocities.
Other than just playing with the LabRadar, we hope to confirm that the reloaded rounds are subsonic when fired from both a handgun (Walther PPQ Navy with 4.6″ barrel) AND a rifle (Kel-tec Sub-2000 with a 16.25″ barrel). We expect the rifle rounds to go a bit faster as the bullet will spend more time behind the expanding gunpowder, but we hope they will remain subsonic. For the record, the speed of sound on a nice day, with low humidity, at sea level is about 1,125 feet per second (fps). This number will change primarily based on temperature (although for the sake of science, we’ll note that humidity and elevation play a small role as well), so to be safe, we’ll say 1000 fps will stay subsonic on all but the coldest days.
We set up at a 100yd rifle range and shot these tests from a bench. We set up the LabRadar on on the “Bench Mount” accessory, which is great for use when you are sitting at a bench. The LabRadar can also be screwed into a standard tripod mount, so you can set it up for use for prone and standing shooting positions. Next, using the notch on the top of the LabRadar, we made sure the LabRadar was pointed at our target downrange. Note, the LabRadar goes next-to, not in-front-of, your muzzle. This addresses the first major drawback mentioned above.
The LabRadar has a bit of a learning curve when it comes to configuration; the menu flow isn’t as intuitive as I’d like. That said, if you keep the manual handy you should have no problems. The one thing you’ll probably want to set up each time you use it is “Trigger Level”. This sets the sensitivity of the LabRadar to gunshots, you want the LabRadar to “trigger” — and therefore start tracking — on gunshots right next to the LabRadar. At a busy range you’ll have to play with this number a bit to ensure that only your own shots are starting the bullet tracking. There are several other settings and tweaks you can make in the configuration options. Be sure to let me know in the comments if you’d like to see a follow-up post with some more detail!
Running our Test
Once you configure the LabRadar you can simply start a new “series” (a recording of a group of shots), and hit the “arm” button to start collecting data. Note, this should be the last thing you do before picking up your firearm and shooting as the LabRadar will “disarm” after a certain number of seconds.
As you can see below, for each captured shot, the LabRadar will show the speed at the muzzle, and then at several distances downrange for each shot, pretty cool!
This data is saved internally on the LabRadar, or optionally on an SD card. This takes away a LOT of the pain of reading and recording data. When you get home you can pull all of the data into a spreadsheet for archiving and analysis. There is also some mystery bluetooth functionality built into the LabRadar. Per the manufacturer, while the hardware is there currently, no bluetooth features are implemented… yet.
Once we finished shooting 4 series of 10 shots each, one series for each firearm/ammo combo, we got home and put the data into a spreadsheet and eventually the graphs below. One note, the data sets for the 133ft and 164ft measurements showed a lot more variations and missing data points than the other. We suspect this is due to shooting a few inches over the 50yd target stand shown in the images above. Mr. SiL once had a career working with radio signals… suffice to say there is a very good technical reason for this. What you need to know is “don’t shoot just over barriers or you might get less accurate results”.
Blazer Ammo – Sub-2000 vs PPQ Navy
As you can see from the chart above, using the same ammo we measured about 100+fps additional speed when the same ammo was shot through the Kel-tec Sub-2000. Those extra 11+ inches of barrel made a significant difference in speed. The speed at the barrel for both firearms was supersonic, with the handgun-fired rounds going subsonic at about 60ft.
As a side note, when bullets transition from supersonic to subsonic they will lose accuracy. When the sound wave moves from behind the bullet to the front it pushes a wall of pressure from the back of the round forward. Imagine this sound wave giving a small knudge to the back of the bullet in-flight. This is pretty important for very long range shooting, but less so for our 9mm use cases.
Reloaded Ammo – Sub-2000 vs PPQ Navy
As we suspected, our reload featuring 147gn PC Bullets from King Shooters Supplies were subsonic through both firearms, with the fastest Sub-2000-fired bullets almost hitting our target max speed of 1100fps. These loads are not going to qualify as “major” in any league that measures the “power factor” of bullets. However, they work for our 3 Gun Nation and Steel Challenge use cases this season.
- Verifying your reloads and testing new factory ammo with a LabRadar Chronograph is easy and safe
- Don’t shoot over a barrier if you are measuring with a LabRadar if you’d like accurate results for speeds PAST the barrier
- Special shout out to King Shooters Supply, they make great bullets (at a great value) for reloading and sponsor our Steel Challenge League
We hope you like this post, and if you’d like to see more material on reloading and testing or have any questions, please let us know in the comments below!