Hello all, I am loading up .223 using 55gr. Hornady FMJ-BT W/C bullets for the first time.

My Hornady book is saying C.O.L. is 2.200" using H335 starting load of 20.8 gr

Cases have been trimmed to specs. PMC Bronze factory ammo bought and fired by me. First time I'm reloading it.

Now, on my test bullet (no powder or primer) I have found that when seating to C.O.L. 2.20" that puts the case mouth just over the top of the bullets cantalure. So I tried another test bullet. This time my Lyman book, 55 gr. Jacketed SPT 2.260" OAL and the case mouth was just over the bottom of the cantalure. What's wrong? I know I can adjust the seating depth and make the case mouth fall right where it should but remember I'm a new guy and I don't want to go changing things around from what the books say. So what's wrong?

Thanks for the help .

Not cantalure. In a 223 why does it matter where the case mouth ends up on the bullet ? You are not crimping 223s are you ? The col will be different w/ different bullets AND in different rifles of the same chambering.
The only one that matters (to you) is yours.
The col is only a standard number. Nothing more.
The Nosler manual even tells you this and that best accuracy is generally longer. Nosler also shows you how to find the optimum col for a bullet in your rifle.

Figure what your OAL needs to be and ignore the cannelure.

quote:

Figure what your OAL needs to be and ignore the cannelure.

+1

If you are not going to crimp don't worry about the canalure.

Keep your length at 2.250 or less and rock on.

Are you loading for an autoloader or a bolt gun?

I have a different take on it; Forget the OAL specs and put the bullet where you want it in terms of cannelure, or distance from the lands if you are at the stage where you are playing with that parameter. If you are shooting an AR, seat the bullet to the cannelure. If you do not have one, it has to fit into the magazine. If you are shooting a bolt gun, seat it to be just off the lands, and you can play with that to see how it shoots. Every makers bullet cannot possibly fall into the same OAL. You are right to follow the book; up to a point, then experience takes over.

Good points dcpd. In an AR I still do not crimp. I load them to fit the chambrerr/land relationship AND that will fit the mags.
Since I load for more than 1 AR, sometimes I have to compromise so that the reloads work in all of them AND then see how they shoot in a bolt gun.
I got the impression the OP was looking for info on (1) gun.

I'm shooting a semi.

quote:

Originally posted by ted thorn:
If you are not going to crimp don't worry about the canalure.

Keep your length at 2.250 or less and rock on.

Are you loading for an autoloader or a bolt gun?

Then load to fit in your magazine

This is usually around 2.250

If your not crimping pay no attention to the ring

I usually don't crimp in the AR platform but here recently have started using the Lee factory crimp very lightly crimping on my last station on my dedicated AR press

Your doing nothing wrong. Seat to the cantalure.
The bullet MUST clear the front of the magazine without touching.

I am loading a 55gr TMJ from X-Treme bullets. I seat to the top of the cannelure and then us a lee factory crimp die for a mild crimp. This results in an OAL of 2.22 with this bullet, seems to work well with the AR.