factory bullet length???

darcy32171

darcy32171

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I have a question that has started to bother me: When reloading, are all brand bullets (Hornady, etc) all the same length when it comes to figuring out head space????? In my Lee Precision book, 22-250 Remington shows over all length of assembled shell is 2.350. Head space is 1.578.
The factory Winchester 45gr JHP shells, the over all length is 2.33 and the head space is 1.60.

Or, should a guy just re-assemble the reloaded shells and keep in mind to stay at the same over all length of 2.33 and call the head space good?? Darcy
 
The bullet does not determine the head space. Different ogive shapes effect the distance from the lands with a given COL, but that isn't what decides the head space.
 
headspace vs COL

Headspace is a measurement determined from the case head to the datum line of the shoulder of a bottleneck case. This determines how the main body of the case fits into the rifle chamber. Which in turn determines where the case head sits relative to the bolt face, snug is best for pin strike and primer ignition.

Where the bullet sits relative to the lands is called bullet set back. This is a very personal measurement amongst reloaders and varies with each individual bullet ogive and each individual rifle and the number of rounds through a rifle.
Some people claim best accuracy with minimun set back, some say .060" is best, some say.125" is best and some say it varies with bullet construction ie; homogenous to cup and core.

After you have determined the best set back for your load and rifle then the length from case head to bullet tip is your COL and is relavent only to that load and that rifle.

I hope this clears up your confusion between headspace and COL.
COL = cartridge overall length.

Douglas
 
The COAL or OAL found in your manuals is a general spec so that any round you make in that calibre should fit any chamber or magazine for that calibre. .308 Win at 2.80" for example. In your specific gun You might load your 308 to 2.895" and get super accuracy, but it might end up being hard to chamber in my rifle or not fit my magazines etc.

When you seat bullets of the same brand and part # in the same die during the same session and they are not the same OAL length by a couple thousandths of an inch this is because the seating die doesn't touch the tip of the bullet, but rather the edge part way down. The seating stem in the die is kinda like a cone and it fits over each bullet a little differently since not all bullets are made exactly the same. The part of the bullet thats fat enough to actually touch the rifling first is called the Ogive. This is not the exact same spot on every bullet as again they cannot all be made exactly the same.

To complicate it further a .308" 150gr Winchester soft point and say a 150gr Nosler are not likely to be the same shape length or seated to the same point. The only thing they would share is that they are both .308" around and 150grs in weight. This can even be true with different brands of 168gr HPBT etc.
 
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