Cartridge overall length is determined by a number of different factors. One is magazine size, and the ability to feed out of it. This is what the usual stated overall length is. Bench rest shooters typically do not feed out of the magazine, the go directly into the chamber. Now maximum overall length can be from the breech face to the point where the bullet touches the rifling in the barrel. To determine what this overall length is, seat a bullet in a resized case. Seat it out longer than normal. Now chamber the round in your rifle, gently pushing the bolt forward to push the bullet up to where it meets the rifling in the barrel, then pushes the case over the bullet until the bolt closes. Now open the bolt, extracting the cartridge. Some time the bullets will stick in the bore, and all that comes out is the case. Try again, but use a cleaning rod to break the bullet free of the rifling, gently, so as not to move the bullet in the case. You can now measure the cartridge overall length. Now when seating your bullets, you want to make them about .020"; shorter than what you just measured. Every time you change bullet types or weights, you need to re-measure.
The minimum given in Modern Reloading is relative to bullet weight and resulting burn chamber size within the cartridge when the bullet is seated to that length. Shortening the overall length and related burn chamber can result in excessive pressures, and should be avoided.
Lengths anywhere between the minimum and maximum are acceptable.
We have found with the new design bullets that are very long and pointed, that our standard bullet seating plug is not capable of seating the bullet deep enough. In the case of .223 caliber bullets, another solution is purchasing a .17 caliber bullet seating plug. Many times this will solve the problem. P/N SB1386 $2.00 plus any applicable taxes and Shipping/Handling. The plug is available at this link: http://leeprecision.com/b-seat-plug-17-rem.html
