243 OAL

[SkipB]

Guys I have a newly rebarreled 243 Mauser action with a McGowan barrel when I check the OAL of a case and 100 grain Interlock it comes out to 2.745 to the lands but the book says max OAL should be 2.630. I`m guessing I can back off to 2.720 and get ,020 off the lands. The bolt closes easily at 2.745. I checked it with the Hornady ogive gauge and I get 2.745 too. What do you folks think?

 

[Rhett Crider]

Needs to fit your magazine and fit your chamber freebore. Max COAL is trimmed case length plus bullet OAL minus case neck length minus bullet boat-tail length. This gives you a full bearing surface in the case neck. Using reloading manuals don't usually help much when you load out longer than SAAMI specs. I use QuickLoads and always start loads 10% back and work up watching for pressure signs. I also use the Hornady comparitor and start 0.025 off lands if I'm not longer than the Max OAL from the above formula. Depending on your chamber and bullet, you may end up with more jump or a shorter COAL than Max.

 

[QuietTexan]

the book says max OAL should be 2.630

The book is just a guideline for fit in multiple chambers. My max OAL with a 108gn Berger is 2.802", I've been shooting it at 2.782".