question on seating depth/ladder test

[krinkansas]

I've always ran a ladder test to find good nodes for the powder charge and then started moving the seating depth around to find best load.

I've read that some folks start with seating depth and then find the correct powder charge.

thoughts on which is better and what charge do you use to find seating depth if you start with that?

 

[Overkill338]

Seems like to me, its pointless to adjust the seating depth until you find a charge that isn't throwing them like buckshot.

 

[Elkeater]

I do powder charge first then seating depth. For me powder charge has always played a bigger part in group size.

 

[Rich Coyle]

Same here.

 

[jimbires]

use a minimum powder charge when finding seating first .

 

[338LAPUA]

I agree with Elkeater

I do powder charge first then seating depth. For me powder charge has always played a bigger part in group size.

 

[jimbires]

read reply 7

https://www.longrangehunting.com/threads/working-up-new-load.206902/#post-1484059

 

[338LAPUA]

I think either way will yield the same results. I think most of us are just stating what has worked the best for us. I'm not going to say the other way is wrong.

 

[Wedgy]

If you were zeroing you're rifle and it was shooting 2-3 MOA at 100 yards would you shoot a ladder test at 600- 1,000 yards with it ?
That is what the seating depth first is for. It is a ROUGH seating depth test, not fine tuning. For instance Berger found in some rifles their VLD's shoot horribly at a given seating depth so they advise to do ~3 shots at 4 different seating depths(same charge) and usually one group will stand out from the others. Then do your load development/ladder/pressure testing and fine tune the seating depth after you have zeroed in on your load.

 

[LongBomber]

I run something like the berger seating depth test first. 3 shots starting on the lands and then stepping the seating depth .020" off till I get to .060" off. Unless its a copper mono bullet, then i just go .030/.050/.070
I pick the best of those and then do a ladder. To get a really good ladder you need brass that has been at least once fired anyways. May as well do a seating test than use that brass for the ladder

 

[jimbires]

there was a better explanation in one of the threads , but I can't find it . he pretty much said you want to find good seating independent of powder influence . most likely you're not on a powder node at a min powder charge , so find your best seating there . now you can work powder knowing the bullet jump is not at a scatter node . I've done this a few times and it seems to turn your seating setting into bullet / barrel , powder doesn't matter . I've switched powders and seating was the same .

as wedgy mentioned above . if you are shooting powder ladders at a few hundred yards and the seating is at a scatter node , what results are you going to get ? most likely a finicky load at best .

 

[Greyfox]

It really depends on the cartridge, and my level of past experience with it. For example, if it's a 308, 300WM, 6.5x284, or 6.5x47, and a few others I've used over the years, Ill work with seating depth first using a proven powder(s). Generally, powder performance is more predicable then seating depth. If the cartridge is new to me and information limited, I'll start with powder and seat at .020", (or magazine length). I won't waist time with a serious ladder until I feel the barrel has settled in, using this settling time to juggle parameters/components to what looks like a promising load. If I'm testing a different(or new lot) of bullet or powder with an existing load, I'll run the corresponding ladder, seating/bullet; charge/powder.

 

[Tex_Hunter]

I tend to start with charge weights at a fixed COAL, either manufacturers recommended jump or longest length that will feed from the mag, and look for not just the best group but narrowest velocity spread as well. I'll usually do a velocity ladder first where I focus entirely on numbers from the chrono looking for flat spots regardless of group size. I'll then pick the fastest flat spot load up 5 rounds at each charge weight bracketing it and shoot for groups.

That will usually yield something in the 0.5MOA range with single digit SDs in my experience so I call it good at the point. Honestly, unless it is much more than 0.75MOA I still wouldnt mess with it as long as it still had single digit SDs.

Shooting bughole groups is fun for throwing shade on other people at the range or if you are a bench rest shooter, but for practical shooting disciplines and field use if you look at WEZ analysis, group size has a negligible impact on hit probability once you get below 1MOA.

 

[ronstone09]

I've always ran a ladder test to find good nodes for the powder charge and then started moving the seating depth around to find best load.

I've read that some folks start with seating depth and then find the correct powder charge.

thoughts on which is better and what charge do you use to find seating depth if you start with that?

for my 600 yd accuracy loads i get the best load and then jam the bullets at different lengths in the lands