Load development anomoly?

[Ed333]

Newbie F class re-loader is confused:
I was following the procedure in the Berger's Manual about development of best seating depth, with my Savage 12 F Class 6BR, using Lapua brass, a constant 29.0 gr. load of Varget, and looking for the sweet spot (or band) for Hornady 105 gr A-Max and Berger 95 gr VLD Hunting bullets. I used the Hornady guage for determining where each bullet was touching lands, and then for the A-Max I loaded 6 rounds each for .010 jam, @ Lands, .030 jump, .070 jump and .100 jump. For the Bergers I loaded 6 each at .010 jam, .010 jump, .020 jump, .040 jump and .070 jump. (The .070 jump was an accident, I set the seating die too low and didn't want to pull the bullets). Then shot two 3 round groups for each setting. To my surprise, the best result with the 105 A-Max was .100 jump, and even more to my surprise, the best with the 95 gr. Bergers was the .070 jump. The jam setting on the Bergers was third best, but not that close. For the AMax 105's, the jam setting was second best after the .100 jump. My pre-conceived notion (based on readings and conversation) was that the Bergers would do best jammed, and the A-Max best with .030 jump.
Does this make any sense or should I go back and do it all over? Maybe this should be done at 300 yards rather than 100 yards?
My next step was going to be trying the Berger 95 VLD Target bullets (the base to ogive distance appears to be different between hunting and target Bergers), and then move on to both varieties of Berger VLD 105 gr., and finally Sierra 107 MatchKing.

 

[cowboysnavy]

Did you shoot these rounds in a round robin style or shoot them least jump to most? I ran into Somthing similar and couldn't make heads or tails of it
I finally found my sweet spots after shooting it in a round robin style
The barrel heating up can play ticks on you
I'm sure someone with more knowledge than me will chime in a give you better info

 

[Erik Cortina]

Why do you want to try so many different bullets? Pick one and go shoot! K.I.S.S.!

If they shoot, then don't fight it. No one can tell you what works on your gun better than your testing.

 

[sbrabec]

I found that shooting from 300-500 yds will really tell you what's working for your gun.
Scott

 

[Ed333]

Why do you want to try so many different bullets? ....

At this point it is a matter of what I can find. I have a few hundred of the Hornadys, but don't want to run out, and figured I had better have a handle on a fallback. The dealer shelves are empty around here, except for Berger VLD Match Hunting. I figure I should know the optimum seating depth for each different bullet I might be shooting in this particular rifle. Or maybe I am kidding myself and just enjoy the A/B process.

I think loading up a few more rounds at the 'good' settings and seeing how they do at 300 is the next logical step.

 

[spclark]

I accidentally discovered the Berger 105VLD I like to shoot so much in 6XC prefers jumping over jamming. In fact it shoots great jumped as much as 0.060" in the one 6XC I use for long range now.

Curiously the same is true when I use those in 6HAGAR in a space gun for 600 yards. 0.020" jump is more accurate than touching or jammed.

If you find jumping a particular bullet works in your rifle for your needs, ignore what you refer to as pre-conceived ideas & get on with the day!

 

[6BRinNZ]

Even if you found that they shot best jammed, I would still go back to verify. IMO its sensible to have another range session to validate....i.e. not just because I doubted my results.

IMO the best thing you can do is not worry about whether or not people jam or jump but follow a repeatable process to find out what the gun likes, which it sounds like you are doing.

At some point you will need to try your chosen load at longer distances, but there are plenty of guys at the National and International level that complete load selection at 100 yards before going further out to finally validate the load.

+1 to spclark

Good luck.