Berger Load Development

mytiburon

mytiburon

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I am just about to start developing a load for my 7mm rem mag, my question is should i pick an intermediate charge and adjust the seating depth first to get the best group Or should I seat the bullet .01 off the lands and do a ladder test with different powder charges to find the best charge?
 
Your second approach is probably better. Don't spend the time trying to find the _best_ charge, do try to work up to max and find something that works reasonably well. Then do a bit of work on seating depth (try .010" off vs. .030" off vs. .060" off; if nothing works well you _might_ consider trying .010" or .015" jammed, but jammed-in-the-lands loads are a PITA and to be avoided if at all possible). Once you've figured out what works well seating-depth-wise, you can try doing some final fine-tuning on the powder charge, if needed (it might not be).
 
rnbra-shooter said:
Your second approach is probably better. Don't spend the time trying to find the _best_ charge, do try to work up to max and find something that works reasonably well. Then do a bit of work on seating depth (try .010" off vs. .030" off vs. .060" off; if nothing works well you _might_ consider trying .010" or .015" jammed, but jammed-in-the-lands loads are a PITA and to be avoided if at all possible). Once you've figured out what works well seating-depth-wise, you can try doing some final fine-tuning on the powder charge, if needed (it might not be).
Click to expand...

Isn't that method what usually works best with the VLD bullets?
 
1899 said:
Isn't that method what usually works best with the VLD bullets?
Click to expand...

No it's more of a suggestion... There is an excellent article over at long range hunting that explains the best way to work up VLD loads.

I am jumping .010 with the 210gr hunting VLD in a 300WM and so far have decent results...
 
First, I'd like to say that I'm really looking forward to Berger's coming reloading manual.

Berger Tips for Loading VLD Bullets
The folks at Berger Bullets have just released an interesting technical bulletin that describes methods for optimizing bullet seating depths with Berger VLDs. The document explains how to find the OAL “sweet spot” for VLDs in your rifle. Interestingly, while VLDs commonly work best seated into the rifling .010″ or more, Berger’s research indicates that, in some rifles, VLDs perform well jumped .040″ or more. This is a significant finding, one that’s backed-up by real-world testing by many shooters.

The key point in Berger’s report is that: “VLD bullets shoot best when loaded to a Cartridge Overall Length (COAL) that puts the bullet in a ‘sweet spot’. This sweet spot is a band .030″ to .040″ wide and is located anywhere between jamming the bullets into the lands and .150″ jump off the lands.”

CLICK HERE to download Berger VLD Tuning Tips

Writing in the report, Berger’s Eric Stecker observes: “Many reloaders feel (and I tend to agree) that meaningful COAL adjustments are .002 to .005. Every once in a while I might adjust the COAL by .010 but this seems like I am moving the bullet the length of a football field. The only way a shooter will be able to benefit from this situation is to let go of this opinion that more than .010 change is too much (me included).”

For target competition shooters (for whom it is practical to seat into the lands), Berger recommends the following test to find your rifle’s VLD sweet spot.

Load 24 rounds at the following COAL:
1. .010″ into (touching) the lands (jam) 6 rounds
2. .040″ off the lands (jump) 6 rounds
3. .080″ off the lands (jump) 6 rounds
4. .120″ off the lands (jump) 6 rounds

Berger predicts that: “One of these 4 COALs will outperform the other three by a considerable margin. Once you know which one of these 4 COAL shoots best then you can tweak the COAL +/- .002 or .005.”

OBSERVATION and WARNING
Berger may definitely be on to something here, and we applaud Berger’s testers for testing a very broad range of seating depths. However, we want to issue a STRONG WARNING to reloaders who may be inclined to try the 4-step method listed above.

Be aware that, as you load your cartridge progressively shorter, putting the bullet deeper into the case, you will be reducing the effective case capacity dramatically. With smaller cases, such as the .223 Rem and 6mmBR, moving from .010″ into the lands to .080″ and .120″ off the lands can CAUSE a dramatic pressure rise. So, a load .010″ into the lands that may be safe can be WAY OVERPRESSURE with the bullet seated .120″ off the lands (i.e. .130″ deeper in the case, the difference between .010″ in and .120″ out).
Click to expand...

Alex
 
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