Hello fellow reloaders!

Anyone care to share some "technical" data?

I'm trying to figure out a system of determining accurate bullet seating. At what specific point is a bullet considered "seated into the lands". Does that mean that the bullet's ogive is "just short of touching", "just touching", "hardly touching" or "absolutely touching" the rifling? With a good Forster ultra bullet seater die, I am well equipped to get good precision seating. I'm also able to determine some degree of contact with the lands using a simple black jiffy-marker method. What I'm wondering is what sort of "markings" on the colored bullet would indicate what reloaders would generally call "contact with the rifling." What is specifically meant to seat ".015 off the lands?"

Rod.

welcome.
You will need a method to determine the exact location of the bullet to the lands.
A stony point bullet comparitor is that tool.
there are other methods as well.
as far as distance from the lands, each rifle has it own preferance. best to work up an accurate load then adjust the seating depth to achieve amore accurate load,

'Just touching' means that the ogive of the bullet just contacts the rifling. But the difference between the ogive of the same bullets will show discrepancies of .005" (or more) with the Stoney Point Chamber Gauge, so much appreciated bij Hot Core.
For load development use the Audette method http://forums.accuratereloadin...2511043/m/571104925, and the discrepancies between gap and charge will be eliminated.
Nice day,
Jan

You will find different accuracy results with different bullets or boolits in every rifle. Most cast boolits like to be engraved by the rifling slightly and any bore ride wants to show rifling marks.
Jacketed are different in that you just want to touch the rifling without jamming bullets into the lands. Be aware this can raise pressure so you need to back off the charge and work up again. In fact, you should work loads every time you change seating depth.
Once you find the point a bullet touches then you just seat the bullet .010", .015" or .020" deeper for each accuracy trial after you see how it shoots with the bullet touching.
Some guns and some bullets shoot best .020" off the lands, same with some cast boolits too. Others want to touch. Nothing here is set in stone and you have to find what your rifle likes best. Just be aware, anything you do can change pressures.
I made a Stony point type tool that works but you can also size the neck just a tad so a bullet slides in and out with a little resistance, leave the bullet out long, chamber it and extract carefully so you can measure it. Take an average of a few trials and a little magic marker helps to see things.
It is not rocket science.
Some put a bullet in backwards to check but now you need to know the exact spot on the ogive that a bullet touches anyway. Unless you shoot BR, I don't think you can find a difference with .005" seating change. It's like working loads in 1/10 gr increments with a slow powder! The sun on a barrel has more effect.

The Nosler book gives step by step instructions for this.I posted a reply about it in the Techniques forum to a similar question.

the way I do this is not what you will see in the books. but try it, it works: 1. seat a bullet in a EMPTY case....2. pull bullet but don't bend the case....3. same case start another bullet but seat it long....4. chamber the round and close the bolt...5. open the bolt and you now have a case to set your seater with that is touching the lands. you are only looking for a starting point A bullet compariter would come in handy when you sart changing the seating depth. reloading is addictive!!! good luck