How far off the lands do you start?

[Wrench]

Most accuracy smiths will tell you jam 20 in or 20 out to start. Don't start at a light kiss.

A jam is a nightmare in a hunting rifle.....so 20 off as a minimum.

Without a gauge you can put a dab of super glue in a case mouth of a fired case and chamber it with your bullet of choice. Once set....that's pretty much your kiss length.

You can drop a sized case in the chamber and measure to the case head with caliper or if you can pull the tube, a chamber checker.....them seat a bullet long and lower it in and measure again. You can take the difference and seat the bullet that much....and be at your kiss length.

The actual kiss can be tricky to measure. The important thing is to pick a spot and document it and then work away from it till you satisfy your needs.....like fitting in the mag box or accuracy....etc.

 

[WVELK]

Will throw my hat in a say you goal dictates methodology. I start with .020 off. Some say distance from lands does not matter, some say go with .030 and roll. For me, my “goal” for my magnums is to be able to have three shots inside or cutting the lines of a one inch square on a sight in target at 600 yards. Do you need to be that accurate to hunt? No. But, I am a little obsessed with trying to be as accurate as possible. So in my situation distance off the lands is very important and I can tell you it will often really fine tune your groups as a last or next to last step. But, to answer you question I start at .020 off unless I know what that bullet generally likes. For example, 180 VLDs for me always shoot best jammed .003 to .004 into the lands so I would start there with the 180 VLD and a new rifle. Hope you get whatever accuracy you are looking for my friend.

 

[SloppyJ]

I've been all over the board on this. Once I was a huge proponent for seating depth. I still think it makes a difference because what I've seen but generally I'm looking for a bullet/powder combo that just plain shoots.

I normally start 20 off and do a bunch of powder charge testing. If it won't group semi-decently there, I abandon it and go back to the drawing board.

The more I test the more I see that it's either going to shoot a specific combination of bullet/powder or it's not. From there, I'll do a bit of seating depth testing to fine tune it and call it a day. Gone are the times of trying to force something to shoot with a ton of seating depth testing. If it's not generally close across the board, I don't want to deal with it.

 

[jjohnsonElknewbie]

Whatever depth removes land marks from showing up on my sharpie ink. This has proven simple and accurate for NBT, ELDX, and ELDM out of my 7-08 and 25-284. Not precise I know, but it works.

EDIT: in both of these Tikka rifles, this method puts me at the bottom edge of bearing surface seated at the neck shoulder junction, similar to @Harvey_NW

 

[Harvey_NW]

If I'm restricted by mag length then I load to functional length. If it's got a long throat I prefer to have the bottom edge of bearing surface seated at the neck shoulder junction, don't care about the amount of jump. Anymore my throats are custom cut to be at .050" off with a certain weight class bullet when seated there, and most of the time within in 1 or 2 tests I'm done with "load development". I do zero seating depth testing, if the combo doesn't shoot I swap a component and retest.

 

[SupressYourself]

This may sound too simplistic or generalized, but it's worked pretty well for me. If there's a factory load that uses the same bullet that you want to use, shoot a box of that. If it shoots decent, measure that and start there. Ammo makers have done a lot of testing to determine what's going to work well in a wide variety of guns. You can always do a seating depth test and tweak from there.

 

[Okie_Poke]

I try to keep seating depth as simple as I can. After I've measured my max COAL/CBTO with a Hornady/Stoney Point tool, I pick a seating depth that gives me "enough jump" and is under magazine length, with a preference for seating the base of the bearing surface near the neck-shoulder junction of the case when possible. I also like round numbers (e.g., 15 or 20 instead of 16 or 22) on my seating die micrometer. By "enough jump," I mean at least 0.020" off the lands and often 0.050" off the lands, though sometimes my actual jump ends up being much further depending on the bullet, chamber, and magazine restrictions. If that doesn't give me the precision I want, I switch bullets or maybe powders, but I rarely try to "tune" the seating depth. I view seating depth as a very small "knob" in the load tuning process that's frankly not worth my time to mess with hardly ever. But: (i) I don't shoot VLD bullets and (ii) I'm not shooting F-Class or benchrest or any game animal at >600 yards. I'm not saying the seating depth doesn't ever matter, but if the bullet is that temperamental to tune I don't want to use it. YMMV.

 

[bazzturd]

Will throw my hat in a say you goal dictates methodology. I start with .020 off. Some say distance from lands does not matter, some say go with .030 and roll. For me, my “goal” for my magnums is to be able to have three shots inside or cutting the lines of a one inch square on a sight in target at 600 yards. Do you need to be that accurate to hunt? No. But, I am a little obsessed with trying to be as accurate as possible. So in my situation distance off the lands is very important and I can tell you it will often really fine tune your groups as a last or next to last step. But, to answer you question I start at .020 off unless I know what that bullet generally likes. For example, 180 VLDs for me always shoot best jammed .003 to .004 into the lands so I would start there with the 180 VLD and a new rifle. Hope you get whatever accuracy you are looking for my friend.

Damn! you are shooting 1/6 MOA at 600 yards?

 

[Harvey_NW]

Damn! you are shooting 1/6 MOA at 600 yards?

3 shot groups. So tweak and "tune" until you get one miraculous, non repeatable result, and then run blindly with confidence.

 

[bnewt3]

Just watched EC's video on chasing the lands.

I come from a high performance engine mindset where the answer is always "measure it".

Now I get it.

TLDW
assuming mag length doesnt keep you off the lands anyway
Find Jam(seat a long(long enough to force the bullet to seat deeper when chambered) dummy round and chamber)
remove & measure
-.020 as starting point
load -.020, -.023 -.026 -.029 etc
shoot til you find at least 2 consecutive nodes
this gives you a .006 range for seating depth
Load to that max range -.001(so if the range of the nodes is 2.155-2.149, load to 2.154)
and thats your seating depth

Then if that stops working, load a little longer such as 2.157 and maybe 2.160 and try those.

So its not so much about a measurement, but finding a place where it shoots.

 

[DadWil]

I start ~.001-.002 just off the lands found by a method Thomas "Speedy" Gonzales & Erik Cortina demonstrated in this YT video

 

[Tanner]

The old Cortina method has worked for me on every rifle. Jam a dummy round, measure it, subtract .030 and go. So far with Berger hybrids they all seem to be perfect right there.
I try to stay with bullets I know.
As many others have stated too, mag length also dictates.
In that situation I will go .010 off mag max and start.

Well how far do you know that you’re jammed with this method?

Kiss the lands, find pressure, and roll has always worked well for me. Nice to only work in one direction that way (deeper) as I won’t jam lands for hunting purposes, ever.

 

[Okie_Poke]

Just watched EC's video on chasing the lands.

I come from a high performance engine mindset where the answer is always "measure it".

Now I get it.

TLDW
assuming mag length doesnt keep you off the lands anyway
Find Jam(seat a long(long enough to force the bullet to seat deeper when chambered) dummy round and chamber)
remove & measure
-.020 as starting point
load -.020, -.023 -.026 -.029 etc
shoot til you find at least 2 consecutive nodes
this gives you a .006 range for seating depth
Load to that max range -.001(so if the range of the nodes is 2.155-2.149, load to 2.154)
and thats your seating depth

Then if that stops working, load a little longer such as 2.157 and maybe 2.160 and try those.

So its not so much about a measurement, but finding a place where it shoots.

Cortina is obviously a world class shooter. I am obviously not. But I've been reloading for over 20 years and have chased a few fads and tried a bunch of "conventional wisdom" in that time. I won't sit here and argue that .003" seating depth changes don't matter in benchrest and F-Class world. I don't compete in those worlds and don't shoot those highly tuned systems. But I've never been able to make it repeat in my rifles with the bullets I shoot. So, I will challenge you to prove (to yourself---you don't owe me anything and I don't really care what you do) that Cortina's seating depth "node" approach works in your rifle system. Do it. Select a seating depth using his method, then load 10 rounds. But then test it: pick a random (but safe) seating depth (0.20" or 0.50" away, or the "worst" one you observed using Cortina's method) and load 10 more rounds. Shoot those two loads on the same day (10 shots at same POA, so a different POA for each load, but let it cool however much you want) and see if you can tell any difference in the group size. When I have tried that, I don't see a real difference. I only shoot factory rifles; YMMV.

As another point of reference, when I wrote in to ask Barnes for some load data one time their email back recommended starting their solid copper bullets at least 0.050" the lands and trying different seating depths in 0.025" increments. Not gospel, of course, but I'm more inclined to believe larger moves matter more than smaller ones.

A final observation: depending on what type of bullet you are using, .003" of seating depth variation may be too fine for you to resolve as the bullet may not be consistent enough, even measuring CBTO instead of COAL, to seat to the same measurement every time. Nosler Accubonds and Berger Hybrids are not in the same class when it comes to consitency, for example, though Accubonds usually shoot plenty accurate enough for my hunting uses.

Again, I don't care what you do. If you want to do a bunch of seating depth testing, by all means. I am personally guilty of testing different loads and different things just to see if it makes a difference I can see, or just to try someting new, even when I've been told it won't matter (or that it will). And the Lord knows I've spent way too much time and money trying to get the last bit of accuracy out of a load or barrel. I'm just trying to save you some trouble if you don't want it---I don't think very many people actually benefit from seating depth tuning. The bullet either shoots in that barrel with that powder, or it doesn't.

 

[Harvey_NW]

Just watched EC's video on chasing the lands.

I come from a high performance engine mindset where the answer is always "measure it".

Now I get it.

TLDW
assuming mag length doesnt keep you off the lands anyway
Find Jam(seat a long(long enough to force the bullet to seat deeper when chambered) dummy round and chamber)
remove & measure
-.020 as starting point
load -.020, -.023 -.026 -.029 etc
shoot til you find at least 2 consecutive nodes
this gives you a .006 range for seating depth
Load to that max range -.001(so if the range of the nodes is 2.155-2.149, load to 2.154)
and thats your seating depth

Then if that stops working, load a little longer such as 2.157 and maybe 2.160 and try those.

So its not so much about a measurement, but finding a place where it shoots.

If you like to tinker and test, by all means CM. But if you're after the utmost precision, this is complete BS that has been disproven by multiple ballisticians. It's just random distribution and small sample variability. "Nodes" have never been proven to exist with valid sample sizes with quality components in most modern chambers. I've got a thread on seating depth that's like 18 pages, and there's 1 example of seating depth making a difference on group size that falls outside the statistical variability, and it's a wildcat .17 cal with a super short bearing surface.