Av velocity always changing

[pitdog85]

So this has been bugging me a bit I shoot with a chrono all the time I live deep in the tropics so temperature change is very minimal. I'm using rl16 139 scenars in my 6.5x47l which shoots great however I have noticed the av velocity changes a lot using the same load. One session over 20 shots ab 2745fps. A month later same load similar number of shots av 2727fps then yesterday did 13 shots for an average of 2704fps. ??? I'm loading with a redding beam scale which I think is very accurate responds to single kernel. Anyone got any ideas why the same load will always fluctuate when my temps are within a few degrees of each other all year round??

 

[Ranger188]

First I'd get rid of that Optical chrono. Do you know someone that has a Magneto Speed or Labradar?
Run your rounds over either of one of those and see if thats helps any.
If not, it's something in your reloading process.

 

[pitdog85]

I use a magneto all the time. Rifle is zero'd with it on.