Exceeding OAL and a few other questions...

[Yoshi]

Bought a custom .308 Savage barreled action with a Shilen Ultra Match barrel. The gentleman I bought it from says he runs his OAL at 2.835. Of which, is measured .020 off the lands. (Lyman says max OAL should be 2.810.)

I know the 2.810 is for factory chamberings, but I've not gotten into "chasing the lands" yet. Anything I should be concerned about with this load? He even sent the dies he used, pre-set, to his load data.

In addition he runs his brass at max length - 2.015. Is there any deviation allowed with max brass length when exceeding documented OALs like this? I am not talking +-.002 or more, but will 2.016 be bad? Or just err on the side of caution and trim to 2.014?

Because his barrel is cut outside of factory specs, can I still shoot factory ammo?

 

[IndispensableDestiny]

The SAAMI minimum chamber length is 2.025. 2.016 will not be bad.

You should get a Hornady OAL gauge and case for .308. The distance to the lands depends on the bullet you are using. If you get really into it, make a chamber casting. If you don't get the gauge, you can use the smoke or sharpie method.

My .308 would chamber rounds much longer than those that I reload for hunting. But I reload to the maximum magazine length.

 

[byf43]

Bought a custom .308 Savage barreled action with a Shilen Ultra Match barrel. The gentleman I bought it from says he runs his OAL at 2.835. Of which, is measured .020 off the lands. (Lyman says max OAL should be 2.810.)

I know the 2.810 is for factory chamberings, but I've not gotten into "chasing the lands" yet. Anything I should be concerned about with this load? He even sent the dies he used, pre-set, to his load data.

In addition he runs his brass at max length - 2.015. Is there any deviation allowed with max brass length when exceeding documented OALs like this? I am not talking +-.002 or more, but will 2.016 be bad? Or just err on the side of caution and trim to 2.014?

Because his barrel is cut outside of factory specs, can I still shoot factory ammo?

A couple of things I'd be concerned with -

• IF the dies are 'set', they are 'set' to HIS machine, not yours. (There are ALWAYS some variations in machining!)

• Did he include 'dummy' rounds that you can duplicate, when you set the dies up in your press???????


IF the original owner has a 'non-standard' chamber/throat in the barreled action, he apparently did the load work-up to make the rifle 'shoot'.

Just my 2¢.

 

[Pinecone]

Heck, I just worked up a load for my .308. And the gun shoots best with a COAL of about 2.860" about the max length for the magazine. It might shoot better with longer, but only with single loading.

25 thousandths long is not much.

And with case length, the SAAMI specs are to not jam the case mouth too far with a minimum length throat.

 

[K31]

You should get a Hornady OAL gauge and case for .308. The distance to the lands depends on the bullet you are using.

This.

 

[Yoshi]

You should get a Hornady OAL gauge and case for .308.

He sent that too... Sorry. Forgot to mention.

 

[fa18hooker]

The only thing a longer neck gets you is more neck tension...if you use the right die (or a bushing die), you calculate and use a specific neck tension anyway. There's absolutely no accuracy advantage to pushing the brass trim-to length. As far as loading length, I think you'll have to test at the range. Sherri Gallagher used soft-seating when she won the National Long Range Championship (using the bolt to finish seating the bullet) with zero or one thousandth of neck tension.

 

[shaddydan]

I do the cheap way. I make a dummy round and chamber it. I measure the length and then set my OAL .020 shorter. I was taught this method by a bench rest shooter who is my club champion.

 

[Yoshi]

The only thing a longer neck gets you is more neck tension...if you use the right die (or a bushing die), you calculate and use a specific neck tension anyway. There's absolutely no accuracy advantage to pushing the brass trim-to length. As far as loading length, I think you'll have to test at the range. Sherri Gallagher used soft-seating when she won the National Long Range Championship (using the bolt to finish seating the bullet) with zero or one thousandth of neck tension.

So, she basically set the bullet on top of the case and loaded it?

 

[Pinecone]

Not quite, loaded it long, but with little neck tension.

You can get by with very light neck tension if you jam the bullet into the rifling. But there needs to be some amount of resistance to the bullet moving to get a consistent powder burn.

Longer trim lengths allow seating the bullet further out, which is less jump, which may be more accurate. But the only way to determine the proper seating depth is by shooting a series of groups with the different seating depth, AFTER you determine the best powder charge.

And with many factory barrels (Remigton is know of this) the throats are VERY long, and you cannot seat far enough out to touch the rifling.

 

[fa18hooker]

Gallagher's bullets were treated like eagle eggs...if you bumped the projectile, it would set back in the case, and that bullet wouldn't be used. This is usually the case with VLD bullets, which typically don't like to jump. On the other hand, Berger now has tangent/secant ogive hybrid bullets that have the extremely high BC of VLD's, but can shoot accurately like most bullets. Not sure which bullets you're using, but if you want to try some Bergers, let me know.

 

[Pinecone]

Berger has found that even the VLD can be jumped. After finding the powder charge you want, they suggest loading in 0.030" increment to see what works best, from jammed to as much as 0.120" jump.