chronographing velocitys

[twmule]

i am shooting a 22-250 with a 26'' hart 1 in12 twist barrell hand loads are seirra 55 blitzkings with 34 gr varget behind them and cci br primers. my powder scale is lyman 1200 dps i just chronoed my gun and was supprised in my readings my gun shoots this combo consistantly under 1/2 at 100 so there is no accuracy issues .but how much of a spread in velocity is acceptable and what could be done to fix it . or is there any thing to fix if i can get my gun to shoot this good.

 

[TheSnake]

What were your readings and what type of Chrony is it? I found that if my battery is a little old, I get inconsistent and/or no readings. I replace the battery and all is good again.

 

[camac]

What is acceptable is up to you. At 100yds velocity ES is not as critical except it can put the velocity into a vibration node and cause innacuracy. If you are getting 1/2 inch groups the velocity spread can't be too bad.. At longer distances it can be very substantial. I have pasted some excerpts from JBM on the Blitzkings doing 3600 and 3700 fps.
3700 3600 3700 3600
Range Drop Drop Windage Windage
(yd) (in) (in) (in) (in)
000 0.0 0.0 0.0 0.0
100 -1.4 -1.4 0.9 0.9
200 -5.9 -6.3 3.6 3.8
300 -14.6 -15.4 8.7 9.0
400 -28.6 -30.3 16.6 17.3
500 -49.6 -52.7 28.0 29.3


Note at 100 yards there is no real difference in drop or windage (to 1 decimal place)
at 200 there is 0.4 inches drop and 0.2 inches windage (at 10mph)
and at 500 there is 3.1 inches drop and 1.3 extra windage at 10 mph.