Bullet jump starting point

[Larryh128]

I'm loading some Berger 130 gr VLD's in a 6.5 Gap that will never be anything but a target rifle. I've got 2 very accurate loads using RL-26 and H1000 in case 1 or the other powder goes awol on me. I'm looking for opinions on where to start from the lands. My initial thought is to start 10 thou off and increase 3 thou per load. Ideas?

 

[tthomp302]

I always start 20 thou off and work closer and further from there. I've been very lucky in the fact that 20 thou seems to work perfectly for me.

 

[L.Sherm]

If its nothing more than a target rifle .010 in an work .003 backwards

 

[DaveTooley]

I start with the bullet touching. The land mark is half as long as it is wide. I then increase the powder charge until I reach max pressure with that seating depth. That's the worst case scenario for pressure. I'll start seating the bullet deeper .005" at a time shooting three shot groups @200. Some where along the line I may have to go up on the powder charge to tune out the vertical as pressure has decreased with the change in seating depth. If that bullet doesn't show me anything by the time I get .025" deeper I start the process over with another bullet.

 

[SKWERLZ]

10 off with VLD and 20 with hybrids/smk.
It’s more a habit than a set rule.

 

[Larryh128]

10 off with VLD and 20 with hybrids/smk.
It’s more a habit than a set rule.

Great info everyone, I have 2 very good loads that won't over pressure BUT I'm used to seating for mag length with copper bullets for hunting so strictly target is new ground.

 

[Bill Norris]

I start with the bullet touching. The land mark is half as long as it is wide. I then increase the powder charge until I reach max pressure with that seating depth. That's the worst case scenario for pressure. I'll start seating the bullet deeper .005" at a time shooting three shot groups @200. Some where along the line I may have to go up on the powder charge to tune out the vertical as pressure has decreased with the change in seating depth. If that bullet doesn't show me anything by the time I get .025" deeper I start the process over with another bullet.

Are you starting with a middle of the road powder charge with the bullet touching the lands?

 

[AlNyhus]

Starting 'in' the rifling, there's only one direction to go when tuning seating depth. -Al

 

[powderbrake]

I always start at "just touching", then work in and out in .003 increments.

 

[Gargoyle]

I always start at "just touching", then work in and out in .003 increments.

X2

 

[D-4297]

Shooting TR , I start Hybrids and TMK's at .005 off touch . Found they work there or at .020 . But I do get my charge weight into middle of the node , and a good grouping before playing with seating depth . VLD's , Hybrids , and TMK's tend to be a little touchy on seating depth . TMK's ? The closer the better .

 

[jepp2]

I always start at "just touching", then work in and out in .003 increments.

I usually start at 0.020" jump for many bullets, but soon I am going to convert to this ^^^

That said, with my Berger VLD-H I have found the best accuracy across several rifles with a 0.050" jump. And if you follow Berger VLD recommendations:

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

 

[Fast14riot]

If you have no idea where to start, consider your powder choice and potential throat erosion. If its a hot powder and you expect .001"/100 round erosion, it makes no sense to start in the lands.

Start .005-.010 off and test back in .006" increments as you will typically find two seating depths .003" apart that work. If you shoot two not touching, skip the 3rd round as you can't shoot a group smaller with more rounds. When you find the good seating depth, go one more .006" step. If that doesn't look good, you landed between the short and long good seating depths, so test .003" either side of the good group.

 

[BJung]

If you have no idea where to start, consider your powder choice and potential throat erosion. If its a hot powder and you expect .001"/100 round erosion, it makes no sense to start in the lands.

Start .005-.010 off and test back in .006" increments as you will typically find two seating depths .003" apart that work. If you shoot two not touching, skip the 3rd round as you can't shoot a group smaller with more rounds. When you find the good seating depth, go one more .006" step. If that doesn't look good, you landed between the short and long good seating depths, so test .003" either side of the good group.

Are you saying that a series of test loads with different bullet seating depths would print groups that will tighten up like ladder test using different charge weights? Would this trend continue as you seat a bullet deeper?

 

[Fast14riot]

Are you saying that a series of test loads with different bullet seating depths would print groups that will tighten up like ladder test using different charge weights? Would this trend continue as you seat a bullet deeper?

Yes. Groups will open and close as you approach or pass a good seating depth. Keith Glasscock has an excellent video on YouTube showing this method, exactly.

 

[JEFFPPC]

Good advice from L Sherm. I start .15 in and then back up .003 at a time. Most often between .007 and touch I find a sweet spot. Last 20 barrels I have jumped 2.

 

[Jeff Porter]

Follow the Berger plan for your Hybrid bullet. They have a VLD and a Hybrid jump plan on their website

 

[DaveTooley]

Are you starting with a middle of the road powder charge with the bullet touching the lands?

It depends on if it's a caliber I'm familiar with. I take my reloading gear to the range. I do the pressure work with one case before proceeding to the accuracy testing. That way if I go to far I wreck one case.

 

[JFrank]

I put them in the lands and run till I hit pressure.

 

[GetReal]

Follow the Berger plan for your Hybrid bullet. They have a VLD and a Hybrid jump plan on their website

Gee.... listen to the bullet manufactuer? What a novel idea....

I'm gonna look for a linkie. Or if you wanna link it to enable my laziness ....

I've been starting just touching, but am being told that can cause problems on target. The fact I haven't been having much success doing that is also a factor....