vld tuning

[jasperjet]

I have a 6x47 lapua chamber rifle and berger 105 vlds.I am having trouble finding a sweet spot. I have h4350 . My question is where should I place the bullet for the ladder test? Jam .040, .080 also do you think I would be better served as a novice to go with 108 bt?,and if so where should I initially seat them) thanks for your help

 

[spclark]

Many would suggest into the lands for VLD's but you may want to start out .015' - 020' off the lands, once you find a charge weight that groups well. Ladder tests can be conclusive if you work slowly with the many variables that need 'fixing': choice of primer, case neck tension, powder choice, charge weight,or velocity) then seating depth at the end.

The 108 is far more forgiving than the 105VLD in this respect so if you want to buy some of both you'll still need to work out what shoots best in your rifle.

I recently was surprised to find jumping .025' gave me far better consistency with DTAC115's than anywhere on or into the lands with two of my 6XC-chambered rifles. That's not to say the DTAC is anything like the Berger 105VLD, but you need to stay open-minded to what works, not always what others say is the rule.

Here's something,long) posted earlier this week over at the National Match Forum:

'We scratched our heads about this for awhile until we started getting feedback from hunters who were competition shooters as well. Many were the same guys who were telling us for years that the VLDs shoot great when jumped. Since a much larger number of shooters were using the VLD bullets with a jump we started comparing all the feedback and have discovered the common characteristics in successful reports which gave us the information needed to get VLD working in your rifle. We were able to relay these characteristics to several shooters who were struggling with VLD bullets. Each shooter reported success after applying our recommendation.

Getting the Best Precision and Accuracy from VLD bullets in Your Rifle

Solution

The following has been verified by numerous shooters in many rifles using bullets of different calibers and weights. It is consistent for all VLD bullets. What has been discovered is that VLD bullets shoot best when loaded to a 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.

Note: When discussing jam and jump I am referring to the distance from the area of the bearing surface that engages the rifling and the rifling itself. There are many products that allow you to measure these critical dimensions. Some are better than others. I won’t be going into the methods of measuring jam and jump. If you are not familiar with this aspect of reloading it is critically important that you understand this concept before you attempt this test.

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).

Trying to find the COAL that puts you in the sweet spot by moving .002 to .010 will take so long the barrel may be worn out by the time you sort it out if you don’t give up first. Since the sweet spot is .030 to .040 wide we recommend that you conduct the following test to find your rifles VLD sweet spot.

Load 24 rounds at the following COAL if you are a target competition shooter who does not worry about jamming a bullet:
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

Load 24 rounds at the following COAL if you are a hunter,pulling a bullet out of the case with your rifling while in the field can be a hunt ending event which must be avoided) or a competition shooter who worries about pulling a bullet during a match:
1. .010 off the lands,jump) 6 rounds
2. .050 off the lands,jump) 6 rounds
3. .090 off the lands,jump) 6 rounds
4. .130 off the lands,jump) 6 rounds

Shoot 2,separate) 3 shot groups in fair conditions to see how they group. The remarkable reality of this test is 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. Taking the time to set this test up will pay off when you find that your rifle is capable of shooting the VLD bullets very well,even at 100 yards).

Regards,
Eric Stecker
Master Bulletsmith'

 

[wnroscoe]

I have a 6x47 lapua chamber rifle and berger 105 vlds.I am having trouble finding a sweet spot. I have h4350 . My question is where should I place the bullet for the ladder test? Jam .040, .080 also do you think I would be better served as a novice to go with 108 bt?,and if so where should I initially seat them) thanks for your help

I have a 6XC that's very close to what you have. It shoots the 105VLD's at +.010' in the lands with 38.2 grains of H4350. If I were to start load development with your rifle, I'd start -.015' from a hard jam and run a ladder. Find the most consistent shooting load and fine tune with seating depth changes .005' at a time coming out of the lands. I've found that with all of my 6mm's and the ones I've built,6BR, 6 Dasher and 6XC) and the 105VLD's, anywhere from just touching to +.015' in is where they all wanted to be. Good luck.