An Exploration To Find My Ideal Chronograph – Sin City Precision
Some of you folks who have sat down with me while enjoying a nice adult beverage may have already realized that not only do I like shooting these precision rifles, but I also like hard data to back up statements. A pet peeve of mine is the generic claim that something shoots “lights out” or that a particular combination shoots really well when there is nothing quantitative allowing me to compare their claim to something else. A claim as simple as that it shoots 0.5 MOA regularly with a 5 shot group if the trigger jockey does their part is a great start. You may have seen the long winded write up trying to determine whether a lab grade scale is actually beneficial compared to the automated systems available for a fraction of the price. This write up is a spin off from that test and has some generic ramblings about the different chronographs I have been using and the journey while using these things. I will discuss what is good, what is bad, and try to back up the observations with some empirical data to help people decide what will work best FOR THEM. Since I am just a free agent in the shooting community, I am not bound to one product however I have been fortunate enough to be surrounded by some really good people in Sin City Precision who have let me use their cool toys to try to learn stuff and in this case do some comparisons between products I normally wouldn’t have access to.
In today’s installment I am doing a comparison between the Shooting Chrony Beta Master (SCBM from here out), MagnetoSpeed V3(MS) and the LabRadar (LR) chronographs. Now this is not your typical write up where someone arbitrarily says the product on their team jersey is better or explains why it is so great without discussing the competition. This is written to help the reader decide what is best for their needs. If you are new to the handloading precision rifle game and don’t understand why I am bothering talking about chronographs, I will type this as plainly and politically incorrectly as I can. Everyone NEED’s a chronograph sooner or later because without accurate info on the speed and spread of a load, session one really is just a blind squirrel finding one’s nuts. In today’s game if one is not using a ballistic calculator (and speed is essential for them to do their job) they are either a caveman or a true precision rifle Jedi.
The items I want to address are things like – “the thing is so sensitive”, “it changes depending on the shadow or the sun,” and “putting that thing on the end of your rifle totally messes up your barrel harmonics and you can’t do load development with that thing attached to find the best groups.” Let us not forget other lovely claims such as – “this thing won’t pick up any shots” and the ever popular “the thing is useless because it always triggers an error and I have to get off the gun to reset the stupid thing.” This was a long journey and did quite a bit of barrel throat erosion while coming to these conclusions. I spent a lot of time trying to make certain products work, slung a lot of lead to see if I could actually measure an effect or trend that was present beyond the spread induced by the trigger puller. Let’s start off with a run down on the units and show some general observations with some sprinkles of data to back up my statements (who doesn’t love sprinkles?).
This is the unit I started out with and I would say I purchased it before I knew any better. The best thing about this unit is the price. I am a techy guy in general, however I found this unit to be a giant pain to change settings. Looking back at the 30 page manual, I get the impression that an Electrical Engineer designed it while in graduate school and decided to put the prototype to market. It makes perfect sense to the programmer and the options work, but translating the symbols to English is likely not for the faint of heart. I finally got it to a setup that worked best and left it alone. After the setup was locked I used paper and pencil to write down all the values and I used an external program to do all the statistics. The SCBM operation was spurious at best. I was stuck shooting at the local county range so it was all off a bench. I had to align the SCBM in front of the line during a cease fire, eyeball it to the target and once live fire started I could get behind the gun and make sure… it was a giant pain. One good thing was the long wire allowed me to have the display at the table and that was convenient.
As I got more and more data and I burned up more and more of my barrel, I kept seeing variance in speed numbers. I saw much more variance in speed than I expected as the day warmed up. My zero was holding and for just a factory 20” Remington 308 Win. barrel it was shooting consistent and tight groups (1.0 to 0.75 MOA 5 round strings was the norm). I was shooting in Vegas, so a 20 degree change throughout the morning was pretty normal for me but the speed changes were much more than I anticipated from just temperature. These speed changes were enough to concern me for drops out at 800 yards with temperature changes throughout the day.
When I was new to precision reloading, I was not confident in my work, looking at my results and reading about all these single digit standard deviation values I was convinced I had no business touching a reloading press… EVER! I wound up using a good factory load as my control to see if it was my loads or the SCBM and environmental conditions that were changing the data. I did quite a few tests with 175gr Federal Gold Medal Match as my control group and looked to see if my loads trended the same leaning towards equipment/weather being the problem in large spreads in speed numbers.
Shooting Chrony: price.
Magnetospeed: good value, easy to use, very precise, can be used at firing line.
LabRadar: excellent data quality, ability to get ballistic coefficient, can get data at same time as real world DOPE.
Shooting Chrony: confusing settings, not precise, has to be forward of firing line.
Magnetospeed: device shifts point of impact and group size.
LabRadar: price, can be triggered by others, battery life.