Maximum case length question

[ar10]

I was reading the Hornady 7th Ed for the .308 service rifle and it states the maximum case length is 2.015". I have a bunch of range brass, CBC, FC, R&P, and Winchester that I cleaned. All of it is 2.020 a little more or less, about 200 rnds. I'm loading all of them with Hornady BTHP 168gr with the OAL of 2.7895 no crimp. The max OAL is 2.81"
The question is: is it necessary that I trim every case to the 2.015 before loading the cartridges? And is this the "head space" issue that I need to know about but still don't fully understand yet?
Thanks

 

[Bullet]

Your manual should list the trim length which will probably be .010 less than the maximum case length 2.015". As long as your brass is between the trim length and the Max length you don’t have to trim. Since your over the max length you will have to trim. This has nothing to do with Headspace. The Headspace your referring to I believe is really Head Clearance. This has to do with how your case fits your chamber. If your case is to big the bolt won’t close but if your case is to small your case will stretch more than necessary when fired. How much or how little you resize your case will determine your (headspace) which can also effect the case over all length.

Make sure you resize your cases before you measure them to see if they need trimmed.

 

[janobles14]

bullet is dead on...

you will have to trim (or really should). shouldered rifle rounds headspace on the shoulder for the most part so you have no headspace issues. accuracy and pressure are your concerns now.

 

[SASS#23149]

the excess length will put the end of the case into the bore,which is smaller than the chamber that it was intended to fit in.Thus the case can't expand fully to release the bullet.

 

[The Bushmaster]

SASS#23149 (Continued) and greatly raising the chamber pressure...Possibly to dangerous levels.

 

[Walkalong]

No, the O.A.L. of your cases have exactly nothing to do with headspace. Keep them under the SAMMI max and you will be fine as long as your chamber is within spec.

In the real world the actual O.A.L. your cases can be is restricted by your actual chamber. As long as the case does not get out of the neck area and into the leade/throat area it will work. If it does there will not be enough room for the neck to expand enough to release the bullet properly which could lead to a blown action and serious injury.

and greatly raising the chamber pressure...Possibly to dangerous levels.

like the bushmaster and SASS#23149 pointed out.


It's best to just go with SAMMI max lengths and stay under them unless you have a custom chamber.

Headspace: Let's not EVEN go there.