El cheapo chronograph

[Aguila Blanca]

Has anyone seen this thing from Amazon? https://www.amazon.com/DTREELS-Preci...s%2C118&sr=8-1

I'm going to be doing some experimenting with .22 LR and this would be a LOT easier to carry around than my industrial-grade chronograph, plus this can be used any time, anywhere. My good chronograph requires a cold range so I can set it up on a tripod at least 15 feet in front of the firing line. This would allow me to show up and just start shooting.

Reviews are mixed. Is it worth 15 bucks to experiment?

[stagpanther]

Looks like a highly-advanced design that you can set up close enough to your muzzle so that it gives you adequate time to run up and tape the velocity number on the front of the unit.

At $14.00 why not buy one and review it (I didn't see any reviews)? That's the cost of just a few rounds of ammo--what's there to lose?

PS--I noticed with all the new small chronos out there that labradar has drastically reduced the price on it's original model--much less than the new units. Yes they are a big pain to set up and have idiosyncrasies--but they still have an enormous amount of capability and data-harvesting capability when everything is just right. When I shoot 22lr I connect the wire trigger cable, the only drawback is that occasionally it will "track" closing the bolt if too sensitive a setting is used.

[jetinteriorguy]

Originally Posted by Aguila Blanca

Has anyone seen this thing from Amazon? https://www.amazon.com/DTREELS-Preci...s%2C118&sr=8-1

I'm going to be doing some experimenting with .22 LR and this would be a LOT easier to carry around than my industrial-grade chronograph, plus this can be used any time, anywhere. My good chronograph requires a cold range so I can set it up on a tripod at least 15 feet in front of the firing line. This would allow me to show up and just start shooting.

Reviews are mixed. Is it worth 15 bucks to experiment?

Well, it’s not too much of a risk with Amazon’s 30 day return policy. So just how does this work? Looks like you just have the muzzle in the clamp thingy. If that’s the case I’d think muzzle blast would eventually pretty much destroy it.

[mehavey]

- delete -

[Ricklin]

I recently got a cheapo from Temu, similar design to my old Chrony but with LED light bars rather than the screens I so hate.
Worked great till I shot it.

[olduser]

From what I see this thing is for air rifles. Max velocity it can handle is 3277 ft per sec.

[Aguila Blanca]

As usual for high-tech Chinese equipment, the same unit is being offered by at least half a dozen or more vendors. It didn't take long to realize that the $14.25 unit ships from China and the shipping costs more than the unit -- $14.99. At that price, I'll order it from one of the vendors that has it shipped by Amazon, just to simplify returns if it doesn't work. Looking through all the listings of what appear to be the same unit, reviews are mixed. The percentage of 4- and 5-star reviews is lower than I would prefer, but some of the comments suggest that the people who dissed it didn't know how to use it.

Originally Posted by olduser

From what I see this thing is for air rifles. Max velocity it can handle is 3277 ft per sec.

Which is more than adequate for .22LR.

[Unclenick]

Just watch out for muzzle blast causing false triggering if you use the air rifle clamp. You may want to pull that off and back up a bit. SAAMI numbers are taken at 15 feet from the midpoint between screens.

I recall Dr. Oehler saying a box of rifle match 22LRs would be within 50 fps of the velocity claimed by the maker, and that could be used to roughly check chronograph calibration. I believe that works because a 22 LR rifle has a huge expansion ratio and the powder burns up in under 20" of bullet travel and for a longer barrel the residual pressure and bore friction track closely enough that velocity doesn't change much between an 18" and a 26" barrel. So you get a much more consistent gun-to-gun velocity number than center-fire rounds produce.

[Aguila Blanca]

Originally Posted by Unclenick

Just watch out for muzzle blast causing false triggering if you use the air rifle clamp. You may want to pull that off and back up a bit. SAAMI numbers are taken at 15 feet from the midpoint between screens.

This is certainly a concern, and may result in the thing being returned.

There is only ONE LED emitter for each sensor, so I tend to think that the reason for clamping the thing to the muzzle is because the muzzle needs to be pretty well aligned with the axis of the two emitters. Backing off even a little bit could result in being off-axis -- especially with a handgun.

The problem you describe is quite real. Many years ago, I set out to quantify velocity loss in .45 ACP as a result of barrel length. I put together four Para-Ordnance pistols, a P14.45 (5" barrel), a P13.45 (4-1/4" barrel) a P12-45 (3-1/2" barrel) and a P10-45 (3" barrel). I was using an indoor range, with a CED Millennium chronograph set up 10 feet from the firing line. All went well with the 5" barrel for establishing the baseline muzzle velocity.

Once I switched to the Commander-length (4-1/4" barrel), things started to go off the rails. I was testing eight different brands and lines of ammo. With the P13-45, 185-gr Speer Gold Dot produced an Error reading on the chronograph. When I switched to the P12-45 (3-1/2" barrel) I got errors with the Speer Gold Dot and with 185-gr Federal Personal Defense. And when I tried the P10-45 (3" barrel) in addition to those two I also got errors with 230-gr Independence FMJ.

Moving the chronograph out from 10 feet to fifteen feet removed the errors.

Consequently, I will be curious to see if this little toy will work with rimfire ammo. I hope so. The CED Millennium is a very nice chronograph, but using it at the indoor range means being there on a day when they're not busy, so the owner can shut down the left side (there's a 12-inch concrete wall between lanes 1-6 and lanes 7-12) to allow me forward of the firing line to set it up and run the umbilical cord back to the shooting bench. It's even worse at the outdoor range of my shooting club, because setting it up and making any adjustments requires waiting for a break in shooting before I can venture forward of the firing line.

If this thing will work, it will be much more convenient. But I very much regard it as an experiment.

As an alternate, I'm also considering this one: https://www.amazon.com/dp/B0C2GX62QS...hk_typ_imgToDp

Some reviewers have commented that it works with 9mm, so I hope it will also work with .22LR.

[Unclenick]

That looks a lot more promising. Of course, with a 22, you might set up the first one and place a sheet of cardboard in front of the first screen to block most of the muzzle blast. Stuff to play with.

[Aguila Blanca]

Yep -- stuff to play with.

I ordered it. Expected arrival before next weekend.

[Unclenick]

Let us know how it pans out. I am curious. Maybe check it against a borrowed unit for cross calibration.

[Metal god]

Deleted, answered my own question