Interesting H1000 and US869 results

[Ryguy]

I had a 338 Lapua re-barreled to a 32 inch 1 in 9. The original factory barrel was 26 1 in 9. The 26 inch barrel preferred 91 grains H1000 under a 300 SMK and would shoot in the .5s but the 32 inch barrel prefers 88.5 gr under the same bullet giving about .75 MOA. 89.5 grains and up would lock the bolt and sprayed bullets 5 feet left then 6 feet right and high. I find it interesting how a 6 inch longer barrel takes so much less powder and is so inaccurate with a near minimum charge. However, US869 and VVN570 repeatedly shot 3 inches at 1000. I am not sure about velocity because I forgot my chrono at home but 102 gr of 869 was giving me 2970 with a 300 Berger OTM a few weeks ago. I am very happy with 869 and is worth looking into but H1000 was disappointing, maybe a little too fast for a 32 inch barrel. Hopefully Lapua will hurry with more 570, this time next year maybe.

71F (I know it's February and its hot outside), 2980 elev, 42% hum, 3-9 mph full value wind.

4 times fired Lapua Brass
Fed 215 Match
300 gr SMK
2.965 Base to ogive, 30 off lands
100 gr US869

91gr VVN570
Berger OTM
2.995 base to ogive, 15 off lands

 

[8AteEight]

What keeps coming to mind is: Yep... good example of "start low n work up" when ANYTHING changes. Since the harmonics changed, the bullet has longer to travel out 'da tube, the rifling isnt the same, possibly the inner-diameter is slightly smaller, tighter chamber, etc. ect. ect.

.......new load any time youve changed anything. (especially as big as a new rifle (thats basically the same as a new gun))