I recently worked up a load for 168 Bergers for both a 30-06 and a 280AI. I started both tests .010 off the lands and jump tested from there.
30-06
I started this load by testing different powder loads seating them all .020, I used IMR 4350 and went 52-53-54gr. 53gr shot the best and from there I loaded up a jump test starting at .010 off the lands all the way out to .130 off going in .030 steps. All the loads shot under 1" at 100 yards and since the 168 VLD's are kind of short in 30cal i chose to seat a little deaper so more bullet was in the case. I settled on .090 off the lands with 53gr of 4350 and the rifle is shooting right at 1/2" consistently. This is a spare rifle now so 1/2" at 100 yards is good enough for me.
Load
Berger VLD Hunter 168gr
43gr IMR 4350
CCI Large Rifle Primers
Lapua Brass
3.408 COAL (.090 off lands)
280AI
I started this load in a similar fashon but started with seating depth first. I started .005 off the lands and jumped by .020 out to .080 off. After .030 my groups opened up. I then reloaded and jumped by .005 from .005 out to .020. The best groups were just under 1/2" at 100. From here I tested different powder charges and am shooting 62.5gr - 64gr of Retumbo. (63gr is recommended max). I started with the 62.5 gr checking for excessive pressure as i went. The 64gr loads were still good but I could make out ejector marks on the brass. Primers looked good and bolt opened easy. However 63gr worked the best and printed 1/4 or less at 100 yards. I am still working on this load but am now going to move out to 500-600 yards and tinker from there. I don't think i will learn much more at 100. I am shooting off of bags so 1/2" or less at 100 yards is pretty good for my ability.
The 280AI will be similar to the 7mm WSM for powder / ballistics. The Retumbo even at 63 gr is a compressed load and I don't believe It is possible to get enough powder in the 280AI case to make it dangerously over pressured.
Load
Berger VLD Hunter 168gr
63gr of Retumbo
CCI BR2 Primers
Norma 280 rem Brass (fire formed to 280AI)
COAL 3.414 (.010 off lands),
The way I measured the lands is by taking a fired brass and rolling the end on a hard surface so that the bullet has a little resistance when inserted. I then carefully chamber the brass with the bullet just barley inserted and close the bolt. When removing the bullet I make sure to use my hand to keep the bullet from being shoved against the side of the action on the way out. I then carefully take the case and measure overall length. I do this several times and average the length, I subtract .010 and load up my first set of loads to this length. Make sure to measure to the ogive.
Hope this helps!! Berger has a good article on dialing in the VLD on their website.
