June 20th, 2018

Chrono Comparison Test: LabRadar, Magnetospeed, & Oehler 35P

labradar chronograph test magnetospeed V3 oehler 35P 6mmBR Ackley BRA

We see comparison tests of cars, cameras, and other hardware. But how about chronographs? What could we learn by setting up three different chronographs, and running a 20-shot string over all three at the same time. One of our Forum members, Randy S. (aka AAA) did that very test with three of the best chronographs you can buy: LabRadar, MagnetoSpeed, and an Oehler model 35P. The MagnetoSpeed was attached to the barrel of an F-Class rig, with the LabRadar placed on the left side of the shooting bench. The Oehler 35P was positioned about 23 feet downrange. The photo above shows the set-up. A 20-shot string was recorded with the results in a spreadsheet.

AAA talks about this interesting experiment in a Shooters’ Forum Thread. Here is his report:

Comparison Testing Three Chronographs

We all have our favorite chronograph. Each gives a number, but how would that number compare to the same round fired with another chronograph? I wanted to know so a friend and I set up the following test with three chronographs: LabRadar, MagnetoSpeed V3, and Oehler Model 35P.

For the test we fired Berger 105gr VLDs over the three chronographs simultaneously. The test rifle was my 6mm BR Ackley (BRA) F-class rig with fire-formed brass and 200 rounds on the new barrel.

Chronogaphs Tested
LabRadar
MagnetoSpeed V3
Oehler Model 35P
Temperature: 86 deg. F
Elevation: 854 feet
Cartridge: 6mm BRA (105gr Berger VLD)
Time between shots: 45 seconds

To start off, five rounds were fired to make sure all systems were recording and to warm the barrel. Then the test was 20 shots fired across all three instruments with 45 seconds between shots. The Oehler was set 7.5 yards from the muzzle so 12 FPS was added to the recorded value.

We were using the internal trigger on the LabRadar. The manual says the Vo indicated is the actual muzzle velocity when using the internal trigger, but not if using the Doppler. The 12 FPS Oehler adjustment (back to MV) was based on the Berger Ballistics Calculator.

Results of the Triple Chronograph Shoot-Out:

labradar chronograph test magnetospeed V3 oehler 35P 6mmBR Ackley BRA

LR-M is FPS variance between LabRadar and MagnetoSpeed V3. LR-O is FPS variance between LabRadar and distance-adjusted Oehler 35P. You can see all three chronos were very consistent. SD was identical with the LabRadar and MagnetoSpeed. CLICK HERE for spreadsheet.

The tester, Randy S. (aka AAA) says: “Judge for yourself, but I was impressed by all.”

Comments by Forum Members
Our Forum members expressed interest in this Triple Chronograph test. Some confirmed that the LabRadar and Magnetospeed give very similar FPS numbers, based on their own tests:

“Great test and thanks for sharing. I’ve tested my MagnetoSpeed and LabRadar together and results are always within 2-4 FPS of one another.” — Big D

“Very happy to see your numbers support my decision to buy a MagnetoSpeed. Had read reports comparing it to the Oehler and the numbers I get seem to be supported by my long range shooting results. Many thanks for taking the time and effort [to perform] this comparative test. Always good to get actual test results.” — Texas10

“I did a 4-shot test with my MagnetoSpeed and another shooter’s LabRadar a couple of days ago. The results were within 4 fps with the LabRadar being optimistic.” — Pat Miles

Forum Member Powderbreak studied AAA’s original spreadsheet from the chronograph trio test, then figured out the shot-by-shot FPS variance between the machines. He concluded that all the machines performed very well. Powderbreak posted:

Analyzing the Triple Chronograph Test — What Can We Conclude?

AAA did a great job of comparing the 3 chronos. What conclusions can be drawn?

1) I have not checked the manufacturer’s claims of accuracy, but the three chronos are very close to one another. There is no way for us to determine the actual true velocities, but we do not need to do so. Any of the chronos would be more than adequate for an accurate shooter.

2) The resolution of the three chronographs is actually pretty astounding. One foot per second (FPS) is a resolution of 0.033%.

3) AAA did a great job of reloading a very consistent round. With an extreme spread of 33 fps out of 3014 for 20 rounds, that is only 1.09% total spread of velocities.

4) There is a closer velocity match between the MagnetoSpeed and the LabRadar, but that does not mean the Oehler is less accurate. There is simply an offset between the Oehler and the other two. This could be due to the greater distance, the location, or the internal working of the Oehler.

5) Believe your chronograph, it is probably the most accurate reloading tool that you own.

Brian Litz of Applied Ballistics carefully explained the operation, set-up, accuracy and comparison of AB’s chronographs in his books. [Those books] are well worth the money, and give great insight into the workings of chronographs.” — Powderbreak

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June 20th, 2018

Novice Shooters Deserve Accurate Rifles Too…

6-6.5x47 Benchrest

On some internet shooting forums, self-declared “experts” advise new rifle shooters to stick to low-end factory rifles. These “experts” (many of whom don’t own a single really accurate rifle), claim that it will take years for a new shooter to learn how to shoot a rifle accurately. So, the argument goes, the accuracy offered by a precision-chambered rifle, with a custom barrel, is “wasted” on a new shooter.

We disagree with that viewpoint, at least when it comes to rifles shot from a rest. We’ve seen relatively new shooters, with help from a skilled mentor, do remarkably well with precision rifles right from the start. With a good bench gun, many new shooters can shoot well under 1 MOA on the first day. Certainly it takes time for a complete novice to learn how to handle the gun and to work the trigger smoothly. However, this editor has personally seen some inexperienced shooters try their hand at benchrest shooting, and within few month they are doing very well indeed at club shoots.

Accurate Rifles Reward Progress As Novices Build Skills

For bench shooting, we think a highly accurate rifle is a much better training device for a new shooter than a typical, cheap factory sporter. With a gun capable of 1.5-2.0 MOA at best, you can never really determine if a “flyer” is you or the gun. Conversely, when a novice shoots a gun that can put 5 shots through one ragged hole, if a shot goes way high or low, the shooter knows his aim, trigger control, or gun-handling is to blame. He (or she) can then correct the problem. And when the shooter does everything right, he or she will see a nice tight group on the target. The accurate rifle provides more meaningful feedback and it rewards progress. That helps the novice become a better shooter in a shorter period of time.

6-6.5x47 Benchrest

A while back, Forum Member Preacher and his “bunny hugger” niece from California proved this point. The young lady, with almost no shooting experience, took Preacher’s 6-6.5×47 and shot a sub-quarter-MOA, 3-shot group at 350 yards. Don’t tell her she needs to stick to a cheap factory rifle. Preacher reports: “My niece flew in from the west coast and came up to visit. When she saw a few of my full-blown varmint rifles, she wanted to shoot one. She did a super job even if she IS a ‘bunny hugger’. She pulled the 1.5 ounce Jewell on a few fired cases to check out the trigger pull and then got in behind the gun and put three shots into a 350-yard target with a one-inch circle.” We measured her group at 0.822″ (0.224 MOA). Don’t tell Preacher that accuracy is “wasted” on novices. He joked: “I sure don’t want her shooting at me ….”

Rifle Features BAT Action, Krieger Barrel, and Russo Laminated Stock:

6-6.5x47 Benchrest

For those who are interested, Preacher’s rifle features a BAT 3-lug action, 30″ Krieger 7.5-twist heavy contour barrel, and Russo stock (with clear coat by Preacher). Chambered in 6-6.5×47 Lapua, this gun “shoots the 108gr Bergers very well” according to Preacher. Yep, we agree with that — even when a novice “bunny-hugger” does the trigger-pulling.

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