Shooting Chrony Gamma Master

[DougMH]

I'm curious what kind of SD you guys are getting with your Shooting Chrony (any model). Why do I ask?

I don't know of anyone how works harder at ammunition preparation and the best SD I've been able to achieve on 10 rounds is 8.5.

Lapua brass, CCI BR primers, concentricity checks, neck wall thickness, weight sorting, you name it, those cases are all the same. I also use an MXX-123 to weight my Varget and Reloder 15/17.

The only thing I do that's not quantitatively measured is the bullet seating force. But certainly to my "feel", there's simply not that much variation.

And more important than anything, the groups at 100yds defy the readings I'm getting.

So, my questions are these:

1) What is the best SD you've been able to achieve with any model Shooting Chrony?
2) Have you done a comparison of your Shooting Chrony with another chronograph (specifically something like an Ohler 35P).

I'ms shooting for a SD of 5.

 

[CaptainMal]

Can't answer your question as mine is so "sensitive", I'm just happy to get a reading.

If all the stars and planets are lined up just right, I have a 6mm Dasher that showed me an ES less than 10 with my old Shooting Chrony.

The gun shoots "horrible" groups at .5's or more so I can't say how accurate the chrony is. Been using that chrony for a couple decades and all I can say is, "It works".

 

[TonyR]

I've seen ES of 1 from 5 shot groups over my Gamma Chrono with my 6mmBR, but I have also seen some pretty strange readings and inconsistencies from it so I bought a chronograph with IR screens. I still get mid-single digit ES from time to time but the results from test session to session are much more consistent. I believe that you need IR screens to get anything reliable. I also rarely find that the best ES is the best grouping load on the target so I just use the average chrono MV results to figure out come-ups. I mostly test at 300 yards but shoot at 600 to 1000 so the come-ups matter. particularly if there are only 2 sighters. The main thing to watch for with the Chrony is changing light levels. I once had a shadow from a safety baffle reduce my MV by 100 fps during a string. That sure had me scratching my head until I figured out, thanks to folks on this site, that it was the chronograph not the load or the gun.

 

[dlong]

I have the red shooting chrony with remote readout and printer. For the most part it works great. every once in a while with the sun and clouds it has to be reset..turn off and on. no big deal for the money. I am very happy with mine.

 

[fdshuster]

From the March issue of "Precision Shooting", an article by James Mock, titled "Does Weighing Charges Help Benchrest Aggregates?" Begins on page 85. An interesting comment on page 89: " there seems to be no correlation between standard deviation and group size. The smallest group fired was a .241", and the three rounds had a SD of 28".

 

[whiskey08]

first couple times i used it i was getting around 5-9fps spread. Last time i used my chrony i was getting a spread of 30 -50 fps, i havent used it since.

 

[Larryh128]

The only issues that I have had are sunny vs cloudy. Some days you need the diffusser over top & some days not. Biggest issue I had was setting the screens too close to the muzzle blast. 223 etc, I'm at 15 ft. Big dogs at 20 ft. I've run 3 rounds thru before at only 1fps difference.

 

[normmatzen]

I found that once I read the directions and followed them including keeping the shots in the "sweet spot" improved performance drastically!

 

[fdshuster]

I've had many failures with my basic "red" Shooting Chrony over the years, and for that reason seldom use it, but recently decided to give it another ( and the last (?) before throwing it away?) try. Both times the sky was overcast and the chronograph has been working perfectly. Even the directions make note that better results will be with an overcast sky, and without using the skyscreens. For me those directions are proving to be true. Think I'll keep it.

 

[338Lapua]

My very best SD has been 5 and that’s with 47.5 gr RL 17.
Im using a charge-master combo and have often wondered if a more accurate digital scale would help with my SD.

I have a CED Chrony and thought it was a piece of junk, because every time I would go to the range, I would get as many errors readings as good readings…..

I felt like placing it under the back wheel of the car and came very close to doing so. Until one day I purchased a
Laser Boresighter… I decided to use it to alien the rifle with the target and 2/3” high over both sensors and directly in the middle..

This is how I now set up my chrony every time. Since I started doing this I have had 6 to 10 missed readings over 100+ rounds and defiantly helped the constancy of my CED Chrony.

To be honest my average SD have been anywhere between 10 and 22 depending on powder im using at the time. 5 is defiantly achievable re RL 17 but is still something im working towards with other powers.

Even my accuracy load using Valget has shown a large SD reading but accuracy inthat rifle is very very good. I measured out a little 4’ graph that I take to the range that I use help set up my chrony.