"Seating down to the crimp groove sure seemed like I was seating deep. The bullets are a 165gr RNFP and it just looked strange to seat that deep. I suppose the point at which it encounters the rifling will be about the same though huh? Meaning the pointed bullets don't impact rifling any sooner than a flat nose the .309 is not at the tip"
The answer to this question is based on that shape of the bullet. In this scenerio, we are assuming a box magazine. "Normally" a round nose or flat point bullet cannot be loaded as long as a pointed bullet. A pointed bullet "normally" has a longer taper, so is smaller in dia at any given point beyond the mouth of the case. When a cartridge is loaded into the chamber, a pointed bullet can extend into the barrel further than can a round or flat pointed bullet - due to the aforementioned taper of the bullet nose. "Normally" is in quotes as there are exceptions to every statement. Another variable can be the size/length of the chamber throat. This also effects how a bullet needs to be seated.
So you see, a pointed bullet seated to "touch the rifling" or "just short of the rifling" will engage the rifling the same as a round nose bullet seated to "touch the rifling" or "just short of the rifling" - even though the two cartridges will be very different in overall length. Also, they will require very different powder charges due to the "difference in available powder space". With a box magazine, you can seat the bullet at any depth you want to within the limitations of your magazine and your chamber. Anything else is pure personal taste or something you found that your particular rifle liked to produce performance.
Basically, you make your cartridge to work in your rifle, not someone elses. Books and Mentors are guides. Your rifle is the Bottom Line. It will dictate something it does or doesn't like. You just have to be observant, and "listen". Let your rifle and your targets talk to you. Remember what works in one rifle may very well not work in another. They are all individuals, with the same basics - like people or dogs.
Some actions have magazines which do not allow the bullet to be seated long enough to come close to the rifling. An example would be XYZ action chambered in ABCsuperfly needs a coal of 2.88" (typical short action) but to feed reliably, the coal has to be retricted to 2.75" due to magazine design. You disdain over this malady, until you get to the range and find a 2.75" cartridge not only feeds superbly, but does a fine job downrange! Ah, the trill of victory!! There are few perfect things, expecially on paper. Perfection becomes in the hands of the shooter; whether the target be paper, steel, or for the freezer, it all comes out the same. "What can you make it do for you." Read all you can find, "listen" to others, and never be afraid to try something, always following a safe path. If it sounds crazy, it just might be. If it sounds dangerous, it probably is, at least until you get experienced. We preach safety for a reason. Stay safe.
Your job is to make your ammunition fit your rifle and make it shoot properly - safely.
Regards,
Sweewater
