Are You Going To Believe Me or Your Lying Eyes?

[370bc]

I have two old chronys. One is a shooting Chrony. The other is Pro Chrony. both are very old models.
Earlier this fall I got some very high readings from loads that read normal. ( !50-200 fps faster than normal).
I did an OCW test with 135 grain Matchkings in a 270 win in a BAR w/BOSS. (Short Barrel).
47 grains of H414 was the best. No crony during the OCW test. Today I Confirmed the 200 yard zero & group. Then checked impact @ 100 yards.
My shooting crony read 2353, 2398 first two shots. My next two shots, My Crony pro read 2260,2334. 31 degrees, cloudy with 8 mph vari wind.
I shot @ 100 yards after 200 zero, impact was 2 inches high. Using my BulletFlightM app on my iPhone, to make that all jive, the bullet must be going 2600fps.
Which one should i believe??
Thank you everyone. Happy New Year!!

 

[370bc]

Cloudy conditions can sometimes dramatically affect readings on chronographs that use light sensors. In addition, change in POI at relatively short distances (100-200 yd) can easily be due to the muzzle pointing up/down as the bullet exits at various times during the harmonic cycle, rather than a large change in MV. Based solely on the information you provided, I don't think you can necessarily draw any definitive conclusion as yet.

I'd suggest trying it again on a sunny day. Also, you might try zeroing at 100 yd and then determining drop at some longer distance (>/= 500 yd) in order to "back calculate" velocity using a ballistic program. 100-200 yd is so close that even minuscule differences in drop/POI can give the false impression of huge velocity changes. You might also consider shooting over both Chronys at the same time if it's feasible to do so.

Thanks for the advise.
I will do just that.
Thank you.

 

[M14AMU]

Thanks for the advise.
I will do just that.
Thank you.

I'd suggest that if you're getting 'adequate recoil' which is indicative of pressure and the load is delivering what you want on the target....forget the friggin chrony and go with the load!!

 

[370bc]

I'd suggest that if you're getting 'adequate recoil' which is indicative of pressure and the load is delivering what you want on the target....forget the friggin chrony and go with the load!!

I agree with go with the load point of view. I have a custom made reticle that goes out to 500 yards by premier on my leupy and would like to confirm the ballistics program and real world trajectory. Going out to 4 and 5 hundred yards seems like the thing to do.
Its fun shooting Yotes again with a semi auto w/muzzle break. Seeing the hits is awesome and fast. I was able to make a second humane hit 100 times faster than my bolt gun.