cart SHOPPING CART You have 0 items

Discussion Forums

Search forums
Forum Index > Rifles general discussion > Chronograph: Magnetospeed V3, Lab Radar, and Shooting Chrony Alpha

Chronograph: Magnetospeed V3, Lab Radar, and Shooting Chrony Alpha

13 Jul 2021
@ 03:55 am (GMT)

James Pigott

Hello everyone:

It’s been a few years since I’ve posted on here. I performed a quick query of the forum and didn’t find a similar topic, so, here goes! Apologies if I missed this topic elsewhere.

I have been using a Shooting Chrony Alpha for around 10 years now. I’ve always been highly suspect of chronographs of this type since it essentially works by measuring the fraction of time of the shadow of the bullet as it passes over the two sensors. Lots of factors from muzzle blast, direction, and orientation of the sun, distance from muzzle, and percent cloud cover (all noted in manual) play important roles in how well the unit works.

I was using my Alpha yesterday to get a feel for two hand loads I had developed for two Tikkas (7mmRM and .300 WM) and noted that the loads were suspiciously low in velocity in comparison to what I thought I might have been getting…

7mmRM: 162 Hornady BTSP with 69.5gr of IMR 7977 @ 2,750 (book says potential for 2,950 with 24” barrel)

.300 WM: 200 Hornady ELDX with 74.4gr of IMR 7977 @ 2,700 (book says potential for 2,850 from 24” barrel)

I was prepared to accept that the barrels may be “slow” or the loads at least underperforming from the velocity spectrum until I noted the extreme spread in velocity. I was getting 70+FPS spread with the 7mm and 100+ with the .300… The 7mm is the most accurate rife I’ve ever owned and will shoot 3/8” of an inch if I’m REALLY doing my part and the .300 will group 1/2” regularly.

So, it lead me to believe that my chronograph may need calibration or perhaps the sun was really causing problems yesterday. Granted, it was partly cloudy which could of caused the dispersion in data, but I wouldn’t of thought it was that dramatic. Perhaps it is the load… However, they have proven to be nothing but consistent.

Now that I’ve taken care of the background so to speak. I would like to invest in a new chronograph that might be less sensitive to ambient light and potentially more accurate. I really like the idea of using a chronograph as a diagnostic tool.

I am considering the Magnetospeed V3 or a Lab Radar. They both have their strengths and weaknesses.

My real only concern with the Magnetospeed V3 is that since it is clamped to the barrel, it seems like that will drastically change barrel harmonics. Sure, it’s no big deal to do a final sight in after a load is found that meets your criteria… But is there potential to find a load that shoots well with the Magnetospeed V3 attached and then find that after removal the harmonics have changed so much as to not carryover the accuracy you saw, or vice versa?

Any thoughts, tips, or suggestions are much appreciate!




13 Jul 2021
@ 10:51 am (GMT)

Scott Struif

Re: Chronograph: Magnetospeed V3, Lab Radar, and Shooting Chrony Alpha
Hi James. The search function isn’t working, but there was a recent discussion on point. The Magnetospeed is accurate for MV.
13 Jul 2021
@ 01:32 pm (GMT)

David Lenzi

Re: Chronograph: Magnetospeed V3, Lab Radar, and Shooting Chrony Alpha
I shoot a lot on public ranges. Have used a "normal" chrono on occasion, decided quickly it was more trouble than I wanted.

I started out with a MSv3 several years ago. I can say with near certainty that it will change your POI. Here are the issues I encountered with the MSv3 in use:

1. it will creep forward on tapered barrels under recoil
1a. as it creeps, the harmonic change will be inconsistent
1b. you can use a muzzle device as a hard stop to index the MSv3 consistently
2. alluded to in 1a above, if you hang a weight on the barrel, POI moves
2a. if your POI change is inconsistent, you get bigger groups

If you have a pic rail on a chassis/stock, you can get a standoff mount that will remove the MSv3 from the barrel. I have read, but cannot corroborate, that the POI shift in this instance is small (.1 - .2 mil) and consistent.

With my heavy-ish barrel target rifle, the MSv3 tended to have a minimal impact on accuracy and a repeatable shift on POI. With my hunting rifles (tapered barrel, no brake/flash hider, etc.), the POI shift/accuracy was variable over even short strings of fire.

The LabRadar is supremely convenient - set it up and send it, switch rifles, etc. with the push of a button(s). Bow, pistol, rifles, doesn't matter. The issues:

1. setup matters and it is mildly technical -
1a. position and offset matter
1b. device settings matter
2. it will miss a shot on occasion
2a. this is correlated with how will you set it up

For example, I shot a 30 rounds from an AR-15 this Sunday to gather some data on MV for a factory load I was testing. The muzzle blast, me being an ox, whatever, caused the radar to shift slightly and it missed two of those shots. It will, of course, pick up the shots of yahoos that fire across your beam/target.
03 Aug 2021
@ 09:46 am (GMT)

James Pigott

Re: Chronograph: Magnetospeed V3, Lab Radar, and Shooting Chrony Alpha
Thanks Scott and David!

I really appreciate the detailed observations. I’ll go with a LabRadar as it seems to meet my needs best.

It also just seems neat!

29 Aug 2021
@ 02:07 pm (GMT)

corrie den haring

Re: Chronograph: Magnetospeed V3, Lab Radar, and Shooting Chrony Alpha
Hi James, I has a crono alpha and found it impossible to set up on range easily, tried all sorts of contraptions with ali poles, sliding poles etc, finally gave up as when i did get it set up too easy for something to go wrong. AND found differing results to what i expected..... SO bought a lab radar and yes can be a bit technical to set up and finicky with direction and don't use batteries as they don't last a session. buy a power pack ~$30. they need a small stand/tripod
also tape a piece of drinking straw on the top sight to line them up with target. they can occasionally give a funny result but >90% of time seem to be bang on. some of my hunting buddies now borrow it!!
27 Sep 2021
@ 12:46 am (GMT)

Todd Free

Re: Chronograph: Magnetospeed V3, Lab Radar, and Shooting Chrony Alpha
I replaced my chrony for similar reasons. Went with the magneto. I changed a load recently, found a sweet spot for accuracy and then checked fps. POI may have changed but once it is removed it’s fine again.

Much happier with ease of setup and more consistent results. My barrel is .8”, no taper at muzzle. Prevent creep by degreasing first and using some old bike inner tube under strap.



We are a small, family run business, based out of Taranaki, New Zealand, who specialize in cartridge research and testing, and rifle accurizing.