Thread: I have problems (of the load development kind)

G'day Boys, Girls, and Gimp
After going for a range session with a new bipod that works (a super gucci dealextreme jobby), I was a bit confused as to what the results may mean.


I fired two 4 shot groups of the same load as follows:

Tikka T3, .308 winchester
Lapua brass (3rd firing approx)
190 berger VLD Hunting
46gr AR2208 (no pressure interestingly enough)
Federal 210 Primers
2664-2755fps velocity spread over 2 4 shot groups

16 deg
994hpa (not that it really matters)

I gave the rifle a rest for 5 mins in between groups, and tried not to bugger around too much with the round in the chamber, so the powder shouldn't have heated up too much.



1st Group:
1 2664
2 2669
3 2688
4 2705

2nd Group:
1 2672
2 2708
3 2734
4 2755

SO..
Velocities climbed throughout the test, the first group stringed horizontally, and the second one stringed vertically, with similar overall group size.. is there any explainable reason for this to happen? If it was spraying the rounds all over the show I'd probably just can the VLD's, but it seemed to be doing similar things when testing other loads with VLD's in the past. I really wouldn't mind finding a way to get these bricks shooting, they kick ass in terms of wind drift, retained energy, and velocity past 500.. If they didn't boot like a mule they'd be ideal!

Any ideas re: the velocity change/grouping?

Cheers,
Kitto