308 COL seating question

Z

zcrenna

New member
Reloading 308 with RE15 and Sierra MK 165gr.

For this load Alliant's website says COL minimum is 2.8"
same load Sierra's website says 2.75 minimum COL
My LEE Classic Loader kit says 2.75" minimum
And a PDF of Alliant's manual says 2.8"

So, correct me if I'm wrong, but 2.800" seems to be a good COL to seat to and is what I plan to do.

I've seen a few guys around seat very similar loads to 2.82 or 2.83, can someone explain the logic behind this?
I know you wouldn't want to seat a bullet too deep but how would one determine when it's time to extending the COL beyond minimum?

Thanks a lot.
 
B

Bart B.

New member
Bullets are seated so the round will feed reliably from a magazine or fit the chamber as the shooter desires.

There's no requirement that autoloaders have bullets seated to at least one bullet diameter depth. The 30 caliber Garand's 150-gr. M1 bullet has its cannelure (for the case mouth to be crimped on) less than.300 inch up from its base.
 
U

Unclenick

Staff
Zcrenna,

There are no 165 grain .308" MatchKings. There are two 165 grain .308" GameKings, a hollow point (#2140) and a soft point (#2145). There is also a 168 grain MatchKing (#2200). Sierra's manual COL's for these would be a good starting point as they will have tested their own bullet more than anyone else, and their numbers are where their testing showed each one to be working best within the constraints of the SAAMI standard for magazine compatibility. If you want to experiment with different COL's that are individual to your rifle, as many of us do, but I'd suggest you try that after trying Sierra's documented values first. They know their bullets best.

Sierra COL's

#2140 2.750"
#2145 2.750"
#2200 2.800"
 
Z

zcrenna

New member
Unclenick, you're right, I have the 2140's. Not MKs. My bad.

So I'll start at 2.750 and I'll also be watching that video firemoose, thanks for the link.

Thanks very much guys.
 
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