COAL for 7X57

[Jhallford1]

Hello. First post here. In Nosler #9, the COAL for 7X57 is listed as 3.065 I believe. I have a K98 Pre war that was customized back in the 60's with new wood, double set triggers and a Douglas barrel. When I use the Hornady Comparator gauge, with out the Ogive comparator gadget attached, I get a COAL of 2.910. is this much disparity common?

 

[DrMike]

Welcome aboard. Such disparity is not unheard of. It would be uncommon in modern rifles cut to SAAMI standards. Though your rifle sports a newer barrel, it is possible that a gunsmith needs to cut a thread or more. It would be worth discussing with a knowledgeable smith.

 

[JD338]

Welcome to the forum. The good Dr. Has given you some sound advice. Keep in mind that COAL for your consists of the measurements to the lands and what your magazine will allow.

JD338

 

[lefty315]

Hello. First post here. In Nosler #9, the COAL for 7X57 is listed as 3.065 I believe. I have a K98 Pre war that was customized back in the 60's with new wood, double set triggers and a Douglas barrel. When I use the Hornady Comparator gauge, with out the Ogive comparator gadget attached, I get a COAL of 2.910. is this much disparity common?

Since the 7x57 is my all time favorite cartridge I’d love to see some photos of the rifle.

 

[salmonchaser]

Sounds like you have a tight chamber. I am on the lands at 3.150 with my Ruger 275 rigby (7x57)

 

[RL338]

When I use the Hornady Comparator gauge, with out the Ogive comparator gadget attached, I get a COAL of 2.910.

Are you using a mechanical or digital caliper? Did you reset the caliper to zero after removing the Hornady comparator?

 

[Jhallford1]

Mechanical. All of my factory loads, Hornady, nosler etc are seated to 2.96 or so. Just realized that 3.065 is MAX according to the book. Guess that is to accommodate longer throats in the old military chambers.
Thanks for all of the replies.

 

[JD338]

Glad you got it sorted out.

JD338

 

[salmonchaser]

Well that’s interesting in and of itself. I’ve never actually owned any 7x57 factory ammo, doubt I would have measured it anyway. Have you had a chance to measure your overall distance to the lands? My earlier comment was in error as I thought that was what you were doing. What is the maximum length you can get into your magazine?

 

[Jhallford1]

Mauser action, no mag box.

 

[Jhallford1]

Since the 7x57 is my all time favorite cartridge I’d love to see some photos of the rifle.

I think I can do that.

 

[JD338]

Nice looking rifle.

JD338

 

[DrMike]

Sweet rifle topped by quality glass.

 

[wvbuckbuster]

Nice looking rifle. Looks like a hunter for sure. Dan.

 

[SJB358]

Sweet rifle for sure!

I‘d bet there are a bunch of different chambers for the 7x57. It’s been around a long time and everyone has had a wack at making their version.