30-06 C.O.L. Question

[Stevedei]

Hi all, I am a newbie to the reloading and I have a couple questions on the COL of a 30-06. I bought a Hornady handbook and in this book it tells me that the COL on a 150 gr. SST is 3.23. It also tells me that the COL on a 150 gr. BTSP is the same. The SST is a balistic tip and quite pointed where the BTSP is not a round nose but is a bit rounded over. My 1st question is: Is this enough to matter? I would think that they are different bullets and the COL should be different as well. Also in my research on the web I see alot of forums stating the COL of a 30-06 should be 3.34 max. That seems like a big difference to me from whats in this book.
I am wanting to load these SST's to the SAAMT standard because I am going to shoot them in a semi-auto rifle and from what I read I can't load them to 0.20 from the lands as I can with my bolt action. My 2nd question: Do any of you have a different book that has another COL for this bullet?

Thanks
Steve

 

[rcmodel]

SAAMI MAX length for the 30-06 is 3.340", regardless of the bullet used.
It says so in the Hornady manuals 30-06 chapter heading information, and also in the cartridge drawing.

It could be that Hornady is basing the OAL of the two bullets in question on the location of the crimp cannulure, not where the nose of the bullet ends up.
The SST is longer, but the extra length mostly ends up inside the case taking up more powder room.

For a semi-auto, you need to be more concerned with if the loads fit in the magazine and feed properly then with reaching the lands. Which you probably cannot do anyway and still have a semi-auto.

And also if you have enough bullet shank inside the case neck for proper neck tension and no bullet set-back from recoil & feeding.

Were it me?
I would seat to the cannulure of either bullet and call it good, regardless of what the OAL turns out to be.


rc

 

[Mykey]

Were it me?
I would seat to the cannulure of either bullet and call it good, regardless of what the OAL turns out to be.

Good sound advice!

 

[kingmt]

What he said.

 

[ArchAngelCD]

The OAL listed in any manual only tells you what the OAL was on the ammo they tested. The only real OAL you need to worry about is the Min and Max for the caliber you're loading. The OAL listed in any manual is a guideline and not set in stone. Of course you don't want to use a Max charge of any particular powder and shorten the OAL from what was used in the listed load because that could cause an overpressure situation. Don't get too hung up on COAL and take RC's advice, seat the bullet to the cannulure and call it good...

 

[Stevedei]

Cannulure it is then....I appreciate you guys taking the time to help a newbie. Maybe someday I can return the favor to another newbie

 

[jr_roosa]

Yeah, take a look at their 150gr FMJ/BT with an OAL of 3.185 if I remember right. It's super short, but it hits the groove just right. Makes the rounds look funny.

I tried running my garand loads out to the lands for single feed prone match loads and there is so little bullet in the case that I had wild vertical spread and horrible scores. Turns out my gun really likes SMKs just short of magazine length the best.

-J.

 

[ArchAngelCD]

If being just off the lands always results in better accuracy how do we explain Weatherby rifles which are very accurate yet have very long throat?

 

[rcmodel]

+1

And how do we explain factory Match & Varmint ammo not being seated to the lands in anything?

You will have a hard time exceeding the accuracy of some of it with handloads.

rc