consequences of seating depth
it's helpful to keep a few things in mind.
1. depending on headspace and how you resize and your brass thickness, there's probably some wiggle room which means the case will probably be laying on the bottom of the chamber when you pull the trigger, which means the bullet won't be pointing straight down the barrel
2. the firing pin will hit the case in the butt, moving it forward
3. the primer explodes, and may send the bullet forward into the lands where it may even come to rest before the powder ignites
Very good point. We usually kept our bullet seating about .01 from the lands as a minimum on all our hunting rounds as the general consensus was that was a safe place to be to prevent pressure spikes, unless you were a bench rest guy. On one rifle in particular with a short throat this is where we always left it. We would always cycle the rounds after loading and look for tick marks from the rifling since we figured our measuring technique probably left something to be desired.
Anyway several years back we were practicing a bit with some "new brass"
on an early fall day (40's) when there was a noticeable delay in the "striker "
spring. A weak spring being the culprit. Worked fine a few minutes before.
After waiting an appropriate length of time we extracted the "unfired round"
or most of it anyway as the bullet was stuck in the rifling. The weak striker spring, with the new brass and the likely error in our measurements
and no crimp all combined caused the issue ( loose powder seemed to be everywhere) . A freak thing no doubt.
Since we figured this would be undesirable in the field on a hunting trip, we changed the way we did things a bit. We moved the bullet back to .015 as a minimum on this particular rifle and employed a factory crimp. And we did change out all the striker springs on our various hunting rifles. This particular rifle actually liked the change.
Some rifles are more sensitive to seating depth than others with certain bullets. Long throat or short and throat diameter as well are all some of the variables. If someones having a problem with boat tail bullets in a rifle with a long throat, we often recommend trying a flat base bullet.
We never understood the harmonics thing that well except for the theory that is. Winchester came out with the BOSS system for a while many years ago to much fanfare. But it's not mentioned much these days. It was supposedly the "end all" solution to the barrel harmonics issue. OYE