Seating depth variation and dies

[Varminterror]

OK......for grins measured all 5 of my Lee dies sets. On 4 or 5.....one full turn screwed seating knob in 0.055 to 0.057 thousands. So if one wanted to divide the knob into 4th's and then 8ths......half o 1/8 turn would be 1 /16 turn and that would be 0.004. If that turned out to be correct, it would be accurate enough for my use.

But what about the fifth one? The 308 Win? Measured it 3 times and one full turn raised or lowed stem 0.156......or over twice what the other 4 seating dies did. Either I screwed up or something is entirely different with the 308. If seating stem is moving that far, that fast, will be no fine tuning that one.

You’ve missed something, somewhere on that 308win die. Lee dies use an 18tpi thread pitch on their seating stems, so the 0.0556” makes sense (1”/18tpi = 0.0555556” per turn). The 0.156” on the last die is a big miss. Most brand seating stems are all between 18-32tpi.

But base-to-ogive sorting bullets is one of those rabbit hole things we can do, so focused, that we miss the forest for the trees. If I cut my batches of bullets in half by length sorting, then I could afford to pay twice as much for just as many bullets of lesser variability.

We also kinda have to calibrate our brains too - for example, among match bullets, the 105 Hybrid is highly criticized as having lot to lot and bullet to bullet variability. However, it is also highly praised for being highly reliable and ridiculously forgiving. So I don’t even bother sorting or measuring - and I don’t do jump tests. If I start a new lot in a new chamber, I do a bolt lift test, find my kiss length, then back off of that 5-8 thou, and live happy. I’m shooting groups in the 1’s through 3’s, even with my anti-node loads under 1/2moa at 100, single digit SD’s, and every miss on the clock is mine, not my ammo. Why make it more complicated?

 

[Howa 9700]

Response I'm tempted to write would probably fill a page in a book, so instead of that, will just say the experience and this discussion has taught me a lot about this aspect of loading for rifles. Know a whole lot more now about what is going on when that press lever goes down and bottoms out. Appreciate all the help.

If what I'm working on bears fruit, will be back to report findings.

 

[Skgreen]

I am completely comfy admitting that the variations I introduce as a shooter are way beyond what is likely introduced by my reloading practices.

Same here. A few can shoot the difference, but I'm not one of 'em.