berger vld seating depth

[fisherman983]

so I have the book, read the articles and have my max coal for my chamber..but in the book it says to load 24 rounds at 4 different coal lengths to find the "sweet spot".
heres the problem, what powder charger do I use for this test? max charge? min charger? right in the middle? or do I just pick something at random and hope for the best?

 

[trazman]

Well I didnt want to use my repeater as a single shot, so I loaded first 10 rounds at the magazine lands(no jam!) and a made a pressure test with powder. I had a sweet spot just under the max load, so I lowered the charge for 1gr and then I made the seating depth test just like berger says. For me it was the best at mag lenght(1/2moa) and quickly opening up with the last more than 2moa...

So I suggest you that you first find what the max pressure is for your rig and if I remember wright you should do this jammed if there is any chance that you will load so...

 

[benchracer]

so I have the book, read the articles and have my max coal for my chamber..but in the book it says to load 24 rounds at 4 different coal lengths to find the "sweet spot".
heres the problem, what powder charger do I use for this test? max charge? min charger? right in the middle? or do I just pick something at random and hope for the best?

No need to make this complicated. Use a starting load to do your seating depth test. Once you find the preferred seating depth, do your powder charge runup. The preferred seating depth will be the same independent of any other factor.

If you later decide to use a different primer or powder, there is no need to re-test for seating depth as long as you stay with the same bullet. In fact, I use the Berger seating depth test with every bullet I load, whether or not it is a VLD, and have found it to work well.

 

[BrentM]

Interesting, that doesn't usually work for me. For each charge weight there is enough variance in accuracy that I have to test seating depth. I load test rounds at .010 and test powder charge. Once I have max charge I back off .5 and do seating depth test at .010, .025, .050, .075, .100, .125.

 

[benchracer]

When I first started testing for seating depth during load development, I tried it both ways. I have used it as the final step in load development and I have used it as the initial step in load development. I ended up at the same place, regardless of which way I tried it.

Once I proved to myself that the Berger seating depth test worked, I started using it as a standard part of my load development. It was an eye opener for me when I started load development for my 22-250 with the Hornady 52 AMAX, several different powders, and both standard and magnum primers. Regardless of the other components used, the preferred seating depth came out the same every time over the course of multiple shooting sessions.

I have also found that the preferred seating depth of similar bullets tends to be very close to one another when measured with a comparator. I found that to be true in my 6.5x55 when testing Berger 140 VLD's and Hornady 140 AMAX's side by side. The same proved to be true with the 50 VMAX and 52 AMAX in my 22-250. Though both rifles showed a distinct preference for a specific bullet, the preferred seating depth for the types tested proved to be the same for similar bullets.

I have since begun my load development by testing seating depth and never had to tweak it to obtain the desired accuracy following the powder charge runup in any of my rifles.

When it comes to handloading, there are a lot of ideas promoted as internet gospel that I have proved to my own satisfaction to be complete horse puckey. I see a lot of people who seem to believe that the more complicated their loading methods, the higher their accuracy potential. Many seem to believe that every little tweak and ritual raindance used by benchrest shooters will make their factory rifle shoot bugholes. My own experience tells me otherwise.

In the end, the only truly hard and fast rule is that every rifle is a law unto itself. I believe in keeping things simple, only making changes when the simplest method is proven to be inadequate to reach the desired goal. Everyone has opinions. Hard data trumps anyone's opinion any time, mine included. The only way to truly know if something works in a given rifle is to try it and let the results speak for themselves.

 

[FearNoWind]

I develop loads, regardless of bullet (Berger, Sierra, Hornady) using CBTO .020 off the lands. I start just under the mid range manual powder charge recommendations and work up to no higher than 10% below maximum, looking for satisfactory node (watching carefully for pressure signs) and back the load down when any of those might show up. I adjust the best sample load .5 grains up and down to fine tune it to the best I can achieve and then work on seating depths. I have found that if I start with seating depths and try to adjust a powder charge around that I have less control over MV.

 

[Mikecr]

I fully agree with benchracer.
Found the same things in similar ways.

I do Berger's test during initial fireforming of brass, at ~2% under book max(conservative).
Once cases are stable I move to ladder testing with the best of my seating. Believe me, ladders look different with good seated depth -vs- bad. I usually take charges to 'MyMax' as measured at the weblines during the ladder.
Then, when I'm confident in chosen powder charge, I tweak seating a smidge both ways to shape grouping. That is, if the load is a keeper(won't always be).

If the load sucks, and I really really want it anyway, then it gets ugly. My only adjustments left are primers, primer striking, or new barrel. Not a solid plan here yet...
Flash holes, primers, and their striking affect ES. You can change triggers & see it. And of course a new barrel is scorched Earth.
But I'm not so picky on load components. I usually just pull out different bullets, same seating, and re-run a ladder. See if that twirls my propeller..