6.5 cm load build

[fatheeler]

having trouble figuring this out all groups were fairly small .75 and smaller with most in the .50 range
the math seems off and mv seems like it is off compared to grains. wonder if I should contact chrono mfg or am I missing something
65 Creedmoor
berger 130 AR hybrid
h4350
br4 primer
Magneto chronograph
second firing on Lapua brass

GR ES SD MV
41.6 6 11 2813 2797
41.8 12 27 2872 2813
42 16 44 2901 2837
42.2 11 24 2896 2866
42.4 14 34 2906 2872
42.6 9 22 2964 2902
42.8 18 44 2943 2899
43 11 29 2946 2917
43.2 17 41 2986 2945
43.4 12 33 2988 2957

 

[Pvt.Donut]

You show 2 values for MV, are those High and Low? High and Average? The numbers look off, maybe I'm looking at it wrong.

My moneys on 42.8. Between 42.6 and 43 your Velocity is only changing by about 18 fps. Load at 42.8 and you have the ability to load +/-.2 gn's and still have consistent velocities.

Then test seating depth to tighten your groups.

 

[fatheeler]

yes that is high and low, yeah it seems off to me too, like 42 and 42.2 , 42 is faster than 42.2 ?

 

[STOMP442]

Are all velocities spread out or do you consistently only have one high or low? If you have an odd ball what happens to your numbers if you delete just that shot?

 

[walker2713]

How do you dispense your powder? At the .2 grain level it doesn't take a lot to jerk the numbers around. Just thinking of possible explanations.....

Interesting...looking forward to hearing more.

George

 

[dsculley]

So..... What did your target tell you?

 

[hikfromstik]

In this humid one day ,dry the next you could be having scale issues . Turn a small ceramic heater on prior to dry things up ,but not too dry . My scales been acting odd as of lately , especially on humid rainy days .

 

[fatheeler]

I think I do have just one high. I use a chargemaster then check with a balance beam every charge, at a 100yds most were at .50"or better, I live in AZ so don't think I have humidity issue. think I will redo test and record velocity of each shot

 

[Texas10]

The Magnetospeed manual warns that improper distance from the bullet path will effect readings, particularly SD and ES. You don't mention barrel, profile or muzzle dia, or which model M.S. you're using, and if a bull barrel, you're set up might not be the best. Can you elaborate on your equipment and set up?

Manual states sensors must be within 1/8 to 3/16 inch from bullet path.