Chronograph comparison

[Bruce Mc]

Last year I worked up a 270 win load of 62.0 gr of Ramshot Grand and a 150 gr Partition, Nosler case and Federal magnum primer. It shot sub moa group. Average velocity was 2949.4 fps. Standard deviation 19.23, average deviation 15.92.
I've always suspected that my old shooting chrony might be a source of inaccuracy in the velocities.
So, I got me a Athlon Rangecraft chronograph for Christmas and gave it a go for comparison sake. This past week the conditions were comparible to last year.
The results ( same load, same bat time, etc):
Average velocity 2950.4 fps. Standard deviation 18.849 Average deviation 15.68.
So I guess the old Shooting Chrony is still good but I need to work on some consistency with this load.

 

[SJB358]

How’s it shoot Bruce? While maybe not 1000 yard numbers those still seem in the realm of pretty darn good.

 

[Bruce Mc]

The loads shoots consistently at 3/4". I did have one group that shot 1/2". I'm happy with the load but now I'm obsessing over lowering the deviation. It could be as simple as a better scale than the battery digital.

 

[SJB358]

Be interesting to see what it does at distance.

 

[RL338]

That comparison is a lot closer than I would have thought.

 

[JD338]

Pretty consistent better the two chronographs.
May try seating three .005" deeper and another three .010" deeper.

JD338

 

[ElmerThud]

As it is, the numbers matter less than the accuracy so I'd say your load is pretty/very good

 

[NYDAN]

When I first got my Garmin chronograph, I compared the velocities recorded by both the Garmin and my Competition Electronics ProChrony for four sets of loads. Depending on the load (velocity) the Garmin recorded averages of 7 ft/sec to 12 ft/sec faster than the ProChrony. Generally speaking, the difference was .25% to .35% faster for the Garmin. After a few months of use, the Garmin never failed to record a shot and is SO MUCH EASIER to set-up and use.

 

[Bruce Mc]

When I first got my Garmin chronograph, I compared the velocities recorded by both the Garmin and my Competition Electronics ProChrony for four sets of loads. Depending on the load (velocity) the Garmin recorded averages of 7 ft/sec to 12 ft/sec faster than the ProChrony. Generally speaking, the difference was .25% to .35% faster for the Garmin. After a few months of use, the Garmin never failed to record a shot and is SO MUCH EASIER to set-up and use.

Yep, no missed shot, much less set up time and effort, more room in the gear box minus the tripod.

 

[JD338]

I have a Garmin as well and my readings on known proven loads were slightly faster than the Ohler 35 I had. It never missed a reading providing I have it pointed at the right target. I can shoot 50, 100, 200 and 250 yards from my bench but I have to point the Garmin to the correct target to get a reading.

JD338

 

[truck driver]

My light shooting chrony likes to be set up in shade to keep from getting missed shots but it has been very accurate when I do. One of the reasons I haven't jumped on the newer chronographs.
Dewy used my readings to develop some great loads for my 35AI.
edit to add that Dewy adjusted quick load to my velocity findings and powder charges to tune my loads.
His help turned my 35AI into a sniper rifle.

 

[Bruce Mc]

Don't forget that the doppler radar is going to slightly undervalue the velocity due to its angle from the bore line. 5 degrees amounts to a loss of around 10 or 15 fps of actual 3000 fps value compared to parallel to bore as in the shooting chrony or a oehler.

 

[RL338]

When I first got my Garmin chronograph, I compared the velocities recorded by both the Garmin and my Competition Electronics ProChrony for four sets of loads. Depending on the load (velocity) the Garmin recorded averages of 7 ft/sec to 12 ft/sec faster than the ProChrony. Generally speaking, the difference was .25% to .35% faster for the Garmin. After a few months of use, the Garmin never failed to record a shot and is SO MUCH EASIER to set-up and use.

I did a primer test with my son 30-06 this past fall and recorded with the Garmin and Magnetospeed. The Garmin was slower on each recorded velocity.