[tx-rvr]

I am looking at chronographs to test my hand loads. If I can get a good average speed I can use a ballistic calculator to get on target at long range. The more I look the more I lean toward the one that hangs on the barrel. I am not liking the ideal of trying to step out in front of the firing line to see the read-out. Also I might shoot the chronograph by accident . I also don't want to have to haul an extra tripod for the chronograph.
My question then is has anyone used one of the chronographs that hook to the barrel? I read a lot of reviews from people that love them, but I would like to hear from people on this site. Yes, I know they cost a lot of money, but I don't like the range master sending me home for stepping out in front of the firing line to read the little LED.

Steve

 

[haertig]

I can't tell you from MY personal experience, but a buddy that I shoot with has one and likes it. He's into precision shooting. And ANOTHER shooting buddy just bought himself one, but hasn't shot with it yet. Also into precision shooting. The one buddy is using, and the other buddy plans on using, these chronographs for load development, just like you.

 

[buzzsaw]

I don't have one of that type. One consideration that I have read about is that in long range shooting, having it on your barrel will change its harmonics making simultaneous correlation of velocity and group size impossible. On the other hand, one of these, combined with a second chronograph some known distance downrange would allow calculations of ballistic coefficients. In this case you only have to not shoot one chronograph.

For a chronograph with the velocities displayed on the unit (Shooting Chrony, for example) you should be able to see the velocities displayed on the unit at normal distances from muzzle (about 9 feet). If it is far downrange, you should be able to read it through your scope.

I have a CED M2 Chronograph. One nice thing about it is that the control unit is set up remotely from the sensors using long cables. I usually put it on the shooting bench with the middle point of the sensors at about 9 feet from the muzzle. This keeps the expensive part from getting shot, and allows you to see and review velocities, and control the unit without needing to call a cold range to step in front of the firing line. Since I'm a control freak, I also have the optional infrared skyscreens, for when natural lighting doesn't cooperate. This chronograph is available bundled with some sophisticated ballistics software from RSI (Shooting Lab). The downside is of course, schlepping more junk to the range, though a nice bag is available. The closest mine has come to getting shot was when a sabot from a load I was testing (.223 projectile at about 3700 fps from a .308 rifle) hit one of the supports. It left a dent in the plastic, but didn't break anything.

If you load your own, you need some kind of chronograph. Otherwise, you're just guessing and assuming that your loads are performing close to the published velocities, and you have no way of measuring consistency. My reloading mentor and I were both surprised to find that a commonly used powder for pistols and shotguns was turning in velocities 10-12% lower than published-in both of our loads. His with .45 ACP and .38 Spl. and mine with .40 S&W. Two different lots of powder. Other powders came in close to expected, as did some commercial ammo. Without a chronograph, neither one of us would have ever been the wiser.

buzzsaw

 

[MarkCO]

If you can name a chronograph I have not shot over, I would be shocked. From $5K to $50, and still have not shot one. I have sold PACTs, Shooting Chrony's and a few others I bought just because I found something that works better.

Like buzzsaw, I have a CED M2 with all the bells and whistles. I have had one sensor go bad. CEDs charge to fix it was more than just buying a new sensor. It is good, and I have had various times where it faulted. In fact, this response prompted me to get a photo and finally list it for sale, so thanks.

I bought a Caldwell and have tested it against some others. I have a light tripod for it and the whole thing goes in a small tool bag. Connect it to my smart phone and it works like a charm. I actually prefer it over the CED, and a lot cheaper and easier to set up.

I shot a few hundred rounds over a Magneto Speed last week and apart from getting it mounted, it works well. Also has a smart phone connection which is a big deal to me. But I own a few guns I have not yet been able to mount it to. This spring I am going to make a rest that I can mount the picatinny rail adapter on a slide to overcome that.

I shot over one right when they came out and got a lot of faults, but it seems that they have improved and upgraded enough that it is no longer an issue. I would not dissuade you from getting a MagnetoSpeed.

 

[haertig]

One consideration that I have read about is that in long range shooting, having it on your barrel will change its harmonics making simultaneous correlation of velocity and group size impossible.

Simultaneous would be the key here. You could shoot groups of your different loads, pick the smallest group size, THEN attach the chrono and measure velocity using more loads from your smallest-group batch.

If you were shooting 3-shot groups to judge size, then you'd have to have a SECOND 3-shots of that same load to shoot for velocity measurement. So twice the amount of ammunition would be required. You're trading the increased convenience of the barrel-mounted chrono for an increase in ammo costs and reloading time. But if you can afford one of these barrel-mounted chronos, they're not all that cheap, I'll bet a little extra ammunition cost isn't going to bother you too much. Plus, you're not going to be accidentally shooting your chrono so you'll save some costs there as well And the reloading time difference between loading 3 rounds of a specific load and 6 rounds is not great.

My friend mentioned that these chronos that attach to your barrel don't affect group size, but they do affect point of impact. I'm a little skeptical of that claim however. Possibly true at 100 or 200 yards, but I can't see how the barrel attachment WOULDN'T also alter your group size at longer ranges. You're changing the barrel harmonics, and that is going to affect where in the barrel's oscillation cycle the bullet exits the muzzle. How can that NOT affect group size?

 

[tx-rvr]

The gun range where I shoot said that I could only use the chronograph in front of the firing line if no one else was there because of safety reasons. I checked on a black powder site. Several people said to go with the magnetoSpeed unit. They average groups about 1 1/4 to 2 inches lower when using it but all said that group size was not affected out to over 400 yards. Also said that trying to shoot through the screens had some effect on there group size at times. Just shoot for zero or check bullet speed, the MagnetoSpeed was easer to use over all. Sold a gen 2 Colt black powder pistol at the gun show Sat. and bought the MagnetoSpeed today. Will try it out soon.

Steve

 

[haertig]

The gun range where I shoot said that I could only use the chronograph in front of the firing line if no one else was there because of safety reasons.

That's pretty much a deal breaker right there. You could make a dozen trips to the range and never get to use your tripod-mounted chrono in that case. I doubt you could schedule "me, and only me" time at the range in advance.

Given that range rule, I don't see any other choice for you besides the barrel-mounted chrono. Luckily, it appears from everything I've been told personally, and everything I've read in this thread, that this is not a handicap, since the magnetoSpeed is indeed a very good chrono. It costs a bit more than your run of the mill inexpensive tripod-mounted chrono, but that's life. Look at the bright side - your range's onerous no-other-shooters chrono rule will force you (or ALREADY HAS forced you) to buy a better chrono than you might have in the first place!

Enjoy your new toy. I fully expect a report on how you like it to be forthcoming.