Berger VLD's , jump or jam???***w/Range Report

Try a test series that runs from way jammed to at least .080" jump. I have one rifle that prefers jammed and one that prefers a huge jump with the same caliber and load.

Steve
 
Mine prefer's to be jumped slightly, about .004" in this case. Have gotten decent results with a .010" and .020" jam but the small jump seemed to work best.
 
Well I think what I will try is +.020 , +010, 0.00 , -0.010 , -0.020.

There should be a group somewhere in those distances.

Berger also recommends into the lands.
 
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Adjusting powder charge in very small increments accomplishes the same thing.

I prefer to be off the lands just in case I need to extract the ammo

Almost all my VLD's are shot 10thou off the lands - I don't play with seating depths prefering to tune using powder.

If you change your seating depth but keep your powder charge constant, you are effectively changing the pressure curve of the ammo. Same thing as tweaking the powder charge.

Seems to work just fine.

If you are loading from the mag, that will determine your OAL.

Jerry
 
Well I think I'll see what groups best out of the depth's I have then once I see a pattern I'll teak the powder as Jerry is suggesting, I have a long throat in that rifle, 0.080 off the lands to me will be like putting a marble down a funnel.
 
Well to my surprise the best results were at my starting point of 0.020" OFF the lands, as I progressed closer to the lands the groups opened up.Not at all what I expected.

Four shots touching and one 1/4" off.I will stick with this depth and tweak the charge a little and hopefully get a nice sweet spot.

Fail moment today was when I returned home and was going to remove my targets so I could record and measure, they blew off of my target board in the back of the truck!!:eek:
 
Here is the targets from today's test.

After finding what amount of jump they liked I played with a few variations in charge.

All are 5 shots @ 100 yards.

0.020" of the lands, powder was H4350.

Think the key now is gonna be shooter practice.I will load up the 42.5 grain charge and get to the range.


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My best results were 0.015" off the lands. I researched what most were doing and worked up the powder charge to get the best groups. A comparator tool will help make this measurement more accurate. I didnt want to jam the bullet as i use it for hunting and wouldnt want a projectile jammed in the throat of the barrel. Take a look at ladder testing if you havent already done so. It was a big help to my load developement.

Cheers
 
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