Dale: you caught my interest with this statement:
“My Lee Pace Setter dies came with a Lee factory crimp die and I have crimpped every bullet I have reloaded so far. I would think I could still use that die and crimp the bullet anywhere I like as I have been doing. The die makes it's own grove in the bullet. Thanks Dale”
Your statement is testimony supporting what Lee has been saying about their factory crimp die. I use their Factory Crimp dies on bullet that already have a cannelura. I have had second thoughts about not crimping after a loaded round fell off my bench and the bullet popper out spilling the powder.
A few questions entered my mind at the time:
What if that happens when hunting, would I have just been down a round?
If the bullet came lose in the rifle would I have a major malfunction, and be out of business for the day?
I have loaded a large variety of bullets in the 270 over the years. Some have a cannelura and other do not. I normally crimp loads that involve a bullet with a cannelura. Some of my loads are compressed and I feel the pressure of the powder against the bullet might overcome the neck tension. I recently loaded some Nosler bullets that do not have a cannelura. I do have a Lee Factory Crimp die for the 270. It crossed my mind to try crimping a few loads, and mark them so they could be identified after firing.
In the distant past I have seen factory loaded ammunition with bullets have two canneluras. I believe one of those bullets was the 180-grain Winchester Silvertip. Winchester might have been using the same bullet in two or three cases and adjusting the overall length of the load but using the upper or lower cannelura in production.
I have not used an existing cannelura because I wanted the bullet out a little more. The load that comes to mind is the 140-grain Hornady BT. The ideal length for that load in my Savage 110CL puts the cannelura just above the mouth of the case. I have a hundred rounds using that bullet in nickel cases and additional rounds in brass. At this date I would not back track and use the factory crimp die on those loads. The reason being that I was not crimping the loads during development and it would be an untested change. I did try a couple of dummy rounds for neck tension. I seated a bullet in a couple of unprimed cases when setting up the bullet seating die. After getting the desired length I tried pulling the bullet out by hand and that did not work. Next I used my RCBS bullet pulling hammers, and it took three or more hardy blows to knock the bullet lose. I feel that was adequate neck tension.
I have been loading the 105-grain Speer for my 243 Winchester. The bullet does not have a cannelura, but it has passed the hand pull and the hammer puller test.
Bullet manufactures provide their bullets to ammunition manufactures. Nosler and Sierra come to mind. Most of the bullets they offered to the reloader do not have a cannelura. But the commercial bullet manufactures tell them they want a cannelura and where on the bullet they want it. I have a box of premium 150-grain Sierra BT loads by Federal. The difference in the 150-Sierra BT I have loaded is the cannelura on the bullet.
Based on the pictures of your groups using a cannelura I would keep on doing what you are doing. Note that crimped factory ammunition has the cannelura manufacture in to the bullet jacket before loading, not as an afterthought.
