Jump to content

Recommended Posts

Posted (edited)
Confused:

I just measured the camber length, bolt face to lands, on my .308 & I come up with a measurement of 2.5715"
Every manual, website & discussion I can find offers a 'standard' OAL of 2.8"
I was trying to figure out an OAL that would put me .0010 off the lands.
Do I have an unusually short chamber?
I set my headspace with a full length sized cartridge so that there is slight resistance as the bolt cams over. A piece of scotch tape over the case head stops the bolt closing, so I know that's good.
I've been loading to 2.8" and my accuracy wasn't what I expected, although I've not started on development yet.
I have no idea of the make of barrel, it was an eBay special. Edited by robtattoo
Posted

For some bolt action rifles, such as Remingtons, the magazine is often the limiting factor. If you want to use the magazine in a Remington, then the OAL of 2.810 is usually what guys settle on. However, for my Savage 11, I think I can fit a 3 inch round in the magazine. I just loaded up some 208gr Amax to test at 1,000 yards. For the ogive to touch the rifling, the OAL was 2.96"ish. I went ahea and loaded them to 2.940" is for my first load development. I get a different OAL for each bullet I shoot.

 

I can share an easy method, easier than slitting a case neck, to figure out the OAL for any bullet's ogive to touch the lands.

 

Remember, develop powder charge first, then play with OAL.

 

Good luck.

Posted

For some bolt action rifles, such as Remingtons, the magazine is often the limiting factor. If you want to use the magazine in a Remington, then the OAL of 2.810 is usually what guys settle on. However, for my Savage 11, I think I can fit a 3 inch round in the magazine. I just loaded up some 208gr Amax to test at 1,000 yards. For the ogive to touch the rifling, the OAL was 2.96"ish. I went ahea and loaded them to 2.940" is for my first load development. I get a different OAL for each bullet I shoot.

 

I can share an easy method, easier than slitting a case neck, to figure out the OAL for any bullet's ogive to touch the lands.

 

Remember, develop powder charge first, then play with OAL.

 

Good luck.

I do the opposite, I figure my OAL first then charge due to the fact that OAL may change your pressure.  Though I have seldom gone at or past max charges listed for most loads, there are some powders that are quick to go from just under to past max when you change OAL just a bit; but those have been with other than .308s so you may be ok either way with that caliber. 

Posted

I do the opposite, I figure my OAL first then charge due to the fact that OAL may change your pressure.  Though I have seldom gone at or past max charges listed for most loads, there are some powders that are quick to go from just under to past max when you change OAL just a bit; but those have been with other than .308s so you may be ok either way with that caliber. 

That's a good point. 0.015" deeper OAL in 9mm, and I can feel the recoil be a bit snappier.

But in the case of the .308 which uses 40-46 someodd grains of powder, the same OAL change will be a lot less signifcant in pressure increase.

An acclaimed xtreme long range bench rest shooter named Lynn told me that. It makes sense when you think about it. Changing OAL serves only to find ideal jump to the lands. 15 thousandths deeper or longer and I think the velocity will still be in the same accuracy node.

 

Still, what works for some may not work for others. If your method works for you and you've never blown up a gun, then have it partner.

  • Like 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

TRADING POST NOTICE

Before engaging in any transaction of goods or services on TGO, all parties involved must know and follow the local, state and Federal laws regarding those transactions.

TGO makes no claims, guarantees or assurances regarding any such transactions.

THE FINE PRINT

Tennessee Gun Owners (TNGunOwners.com) is the premier Community and Discussion Forum for gun owners, firearm enthusiasts, sportsmen and Second Amendment proponents in the state of Tennessee and surrounding region.

TNGunOwners.com (TGO) is a presentation of Enthusiast Productions. The TGO state flag logo and the TGO tri-hole "icon" logo are trademarks of Tennessee Gun Owners. The TGO logos and all content presented on this site may not be reproduced in any form without express written permission. The opinions expressed on TGO are those of their authors and do not necessarily reflect those of the site's owners or staff.

TNGunOwners.com (TGO) is not a lobbying organization and has no affiliation with any lobbying organizations.  Beware of scammers using the Tennessee Gun Owners name, purporting to be Pro-2A lobbying organizations!

×
×
  • Create New...

Important Information

By using this site, you agree to the following.
Terms of Use | Privacy Policy | Guidelines
 
We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.