Chronographing


Dear Technoid,

Is there a easy way to measure my reloaded shell(s) velocity? Will the chronographs work with shotguns? I have visions of buying a chronograph at cabelas and blowing it apart… at 3ft from the barrel the shot and wad are like a rifle bullet anyway so the thing should read it?

Any thoughts?

Kurt

Dear Kurt,

I use a chronograph on my shotguns all the time. No problem. I have an old ProChrono, but there are a number of good ones out there today. I was told that these chronos read the shadow of the lead pellet. This isn’t quite as accurate as the expensive laboratory “center of mass” chronographs, but it’s close enough.

I’ve never had a problem shooting the chrono, but then again, I have trouble hitting clay targets too. There is some muzzle blast and burnt powder to deal with, so some people put a small piece of clear plastic over the face of the chronograph to protect it. I used to do that, but then I lost the clear plastic piece and never bothered with it again. It didn’t seem to make much difference and the face of my chrono has survived.

Since most of SAAMI (the association that governs ballistic standards in the US) velocities are measured at 3 feet, that’s what I do. I measure three feet from muzzle of the gun to the center of the chronograph (between it’s “eyes” on the top of the chrono). Not only is this the nominal distance, but it is also far enough away so that you don’t blow the chronograph apart and yet near enough so that the pellets haven’t separated enough to, again, blow the chronograph apart.

You can put the chronograph up on a camera tripod if you want to get fancy, but I normally just lay it on top of the front of a trap house and lean my elbows on the rear to get the right muzzle to chrono distance. The guide rods on top of the chrono help line up your sighting. I try to shoot perhaps 6″ to 9″ above the chrono. That seems to work fine. A sunny day is also helpful, but slight cloudiness won’t hurt. Instructions come with all the chronos. It’s not rocket science.

In all, chronographing has been very successful for me. I’ve learned just how bad some of my reloads are and what some of those short skeet tubes due to velocity. Some of the foreign ammo claims wildly optimistic velocities. Different countries measure velocity in different ways and at different distances. Also, I always keep a few high end American trap loads for a reality check, just to make sure that the chrono is telling the truth.

Like all forms of shotgun shooting, if you want to know what you have for sure, you have to do the testing. This is as true of velocities as it is of patterning. If you don’t test, you have to rely on people like me to tell you what you have. That’s never wise.

Best regards,

Bruce Buck
The Technoid writing for Shotgun Report, LLC
(Often in error. Never in doubt.)
http://www.ShotgunReport.com

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