I was wondering peoples' experience on whether it is better to tune the seating depth or the charge weight as a first step in load development, assuming powder, primer, and bullet type are out of the equation. I have tried both and found good results with either method. However there are guys here with way more experience than myself so I though I'd ask. Getting ready to work up another couple of loads for some of my rifles and curious which route to take. I guess my question in a nut shell is does charge weight affect seating depth tuning substantially? Or do bullets in a specific barrel just seem to like a certain amount of jump or jam with minimal influence by how much powder is shoving them down the tube? Thanks for your thoughts!
Ladder test or seating depth first in L.D.?
- Thread starter fujam
- Start date
Charge weight/primer for stable es/sd, then tweak seating depth to tighten group.
I do it after messing with primer and powders. But you’ll find people on both sides that will argue until blue in the face.
Since both sides don’t seem to have any issues in the long run, that would imply that it doesn’t matter when you do it.
Since both sides don’t seem to have any issues in the long run, that would imply that it doesn’t matter when you do it.
Same barrel. I will give the barrel a few minutes to cool down, however, or shoot a couple through the barrel to warm it up before starting.
Out of curiosity why .020 jump? Are you moving out from there? I've always heard start slightly jammed and then once powder is figured out move out with no pressure worries. I was listening to an interview with David Tubb and he was saying that his loads are more often jammed than jumped. He felt it took neck tension out of the equation and gave better results. However I've been playing with loads with bigger jumps recently which don't seem so sensitive to seating depth changes as the barrel wears. Maybe that's why .020 off is a good place to start?
BTW thank you all for the input and replies!
I was watching an interview that 6.5 Guys did on YouTube with a guy (can’t remember name) who said most bullets seem to like a .020 jump.
I test powder loads at .020, then I work at seating depth. I load 3 rounds at .010 into lands, 3 rounds at the lands (.000), 3 rounds at .010 off the lands, 3 rounds at .020 off the lands, etc. until I find the best seating depth group.
I think I Iearned how to mess with seating depth from this article from Berger Bullets.
Getting the Best Precision and Accuracy from VLD bullets in Your Rifle
VLD bullets are designed with a secant ogive. This ogive shape allows bullets to be more efficient in flight (retain more velocity = less drop and wind deflection). While this result is desirable for many rifle shooters the secant ogive on the VLD bullets produces another result in many rifle.
bergerbullets.com
I was watching an interview that 6.5 Guys did on YouTube with a guy (can’t remember name) who said most bullets seem to like a .020 jump.
I test powder loads at .020, then I work at seating depth. I load 3 rounds at .010 into lands, 3 rounds at the lands (.000), 3 rounds at .010 off the lands, 3 rounds at .020 off the lands, etc. until I find the best seating depth group.
I think I Iearned how to mess with seating depth from this article from Berger Bullets.
Getting the Best Precision and Accuracy from VLD bullets in Your Rifle
VLD bullets are designed with a secant ogive. This ogive shape allows bullets to be more efficient in flight (retain more velocity = less drop and wind deflection). While this result is desirable for many rifle shooters the secant ogive on the VLD bullets produces another result in many rifle.
No pressure problems I take it going from .020 to jammed? I suppose maybe this is only an issue if the load jumped is already on the cusp of over-pressure and is then subjected to a jam.
I tend to be conservative on powder loads.
I also start at bottom of the seating depth ladder and work up to the bullets touching/jammed into lands.
I check each case after shooting to make sure everything looks normal (I have at least a min between shots and I find if I keep myself busy with case inspection it’s easier to wait between shots).
I also start at bottom of the seating depth ladder and work up to the bullets touching/jammed into lands.
I check each case after shooting to make sure everything looks normal (I have at least a min between shots and I find if I keep myself busy with case inspection it’s easier to wait between shots).
This sounds technique makes sense and seems wise. I'm a fan of mild loads too. This is a little off subject but somewhere I ran into a article talking about velocity verses pressure and it is not at all linear especially as one approaches max load. Near max, pressure climbs rapidly as velocity might not change much at all. Milder load may in fact be way easier on equipment than those pushed to the max. Also they should be way safer to play with when adjusting seating depth.
I’ve had good luck with a lighter load, but as I’ve stretched out the distance I’ve been getting sorely tempted to see how much more speed I can squeeze out of my cartridge. 
Yeah I know the feeling, as long as you know what you're doing and don't mind the extra wear and tear. I was at the range a couple month ago and a guy was blowing primers testing loads in his AR. I mentioned he was endangering himself and those around him by continuing to shoot loads that were obviously way over pressure. He looked at me and said "oh it's no problem, it happens all the time." I told him it's not fine and he should rethink his approach before he has an accident. I got up and moved to the other end of the line. Hopefully he still has his face and fingers.
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