Garmin MV - at what distance?

[Tesoro]

Has anyone determined what crono distance setting is best to use on a ballistics calculator for the Garmin? It was pretty simple with the Magnetospeed or Ohlers because you knew the distance. I never used a LR. I haven't got around to comparing the Garmin to Magneto but expect mv to be less with the Garmin. Using my load my app shows a decrease of 16 fps at 10 yds from muzzle and 32fps at 20 yds. I can't see how the Garmin could calculate back to muzzle vel because it dosent have the necessary inputs.

 

[Eagle Six]

In the manual it says it has special algorithms to calculate true muzzle velocity. Sounds like smoke and mirror magic!

 

[Tesoro]

In the manual it says it has special algorithms to calculate true muzzle velocity. Sounds like smoke and mirror magic!

Well I am around 25-30fps slower with Garmin than what my magneto read in the past. Found my chicken scratch notes. I guess time to strap on the Magneto, compare to Garmin and waste some good ammo.

 

[Eagle Six]

Well I am around 25-30fps slower with Garmin than what my magneto read in the past. Found my chicken scratch notes. I guess time to strap on the Magneto, compare to Garmin and waste some good ammo.

The results may be revealing. Others are reporting a much smaller difference from MagnetoSpeed or Lab. When I ordered the Garmin I put the MagnetoSpeed up for sale and to my surprise it sold several days before the Garmin was delivered so i could not compare and all the old Crony and Caldwell are long ago gone.

 

[6.5 forever]

My Garmin is 10 fps slower than LR. It was 5 fps slower than Magneto. All testing was simultaneous and with three different calibers.

 

[Coyotefurharvester]

My Garmin is 10 fps slower than LR. It was 5 fps slower than Magneto. All testing was simultaneousl and with three different calibers.

And all are likely within the +,- error probability of the units.

 

[6.5 forever]

And all are likely within the +,- error probability of the units.

I was amazed at the consistency of all the units.

 

[284winner]

Mine are what they are. I'm not comparing, only using drop data to verify. The drop data matches the velocities. That's all that matters to me.

 

[Dimner]

In the manual it says it has special algorithms to calculate true muzzle velocity. Sounds like smoke and mirror magic!

Well... the labradar (original version) has algorithms that do that. If I remember the process correctly, It recognizes, via the radar signal, what distance it the first few bullet velocity readings are at. Then it back calculates the muzzle velocity, i think using an average. I read a post somewhere about the accuracy of the algorithm, it was a reasonable margin of error.

So if the labradar can do it, I bet Garmin will have no problem making the same calculations. However, it would be good to know for sure how the magic works.

 

[Tesoro]

Well if it is truly only 5-10 fps then this is immaterial as it is like max 1/4in drop diff at 1000 yds. It helps to read the instructions! I didnt realize that their was some magical algorithm that adjusted the vel back to the muzzle.

 

[DCC83501]

My Garmin matches my MagnetoSpeed V3 or is within 3-5 fps one way or the other. One reading may be a few fps higher on one shot and the next shot, the other unit may have a slightly higher reading. This with 6.5 Creed, 6 Creed, and 22 Creed. I don't recall any reading having more than 4 fps variance between them. Somewhat limited readings ( maybe 150 or so)

 

[Rocketvapor]

Might call it an "algorithm" but I suspect it's just a "fudge factor" based on measured velocity.
A guess at velocity loss for 2 to 3 yards as a percentage of measured result.

 

[swd]

My Garmin was 1-4fps slower than my friends Labrador. He ordered a Garmin the next day after seeing and using my Garmin..

 

[Rocketvapor]

While the Garmin will read when roughly pointed in the right direction, it still needs to be closely aligned along the path of the bullet. With no alignment aid, that may be tough.

 

[6.5 forever]

While the Garmin will read when roughly pointed in the right direction, it still needs to be closely aligned along the path of the bullet. With no alignment aid, that may be tough.

Have you used one?

 

[Rocketvapor]

Yup. Did a light/heavy primer test with mine,
and a 0.05gr ladder.

 

[DShortt]

So you changed your testing method.

Reality is a perception.

 

[JMayo]

Black aiming line is on the top of the Garmin

 

[Geno C]

My magneto was 22fps faster than the AB radar on 2 different rifles

 

[coldboreshot]

I was amazed at the consistency of all the units.

I discovered same when I compared my Garmin.