Need help identifing a cartridge

[gunshot98]

The gun barrel is stamped 308 x 1.750 is this a 7mm BR? Its a custom rifle that a friend brought in that he inherited from an uncle that passed away. I am going to do a chamber cast to help with this, but just wanted to run it by you guys to see if anyone had the measurements for that caliber and what you thought. Oh also, its in a Remington action and he is going to bring me a case he found also.

[Screwbolts]

The gun barrel markings have already told you what the caliber is and chamber was cut to. A, 308x1.750, cases are made by reforming 308 brass and trimming to 1.750 long.

Ken

[Rifle 57]

That chamber you have is used in Hunter benchrest class competition and it is sometimes called 30x44 it was more popular in the 1980's to 1990's. To make the brass you need to have a 308 win sizer die cut off .250 of a inch to form the brass then you will have to trim the neck back until you get the over all length down to 1.750. The idea was to have a little less recoil in a 10 lb. rifle. It is a very accurate 100 to 300 yard cartridge with low recoil. Most barrels were 14 to 15 twist and guy's used 125 and 135 grn. bullets. I use to chamber alot of them for some of my customers.Also it might have a tight neck and brass will have to have the necks turned down some. Most of the chambers were cut with .330 to .334 diameter necks. When you do your chamber cast you will be able to measure the neck then, unless it is stamped on the barrel.
I might also add that if you don't want to go to the trouble of making brass for the chamber that is on it now it could easily be re-chambered to a standard 308 win with out any set back on the barrel shank.

[leadman]

Sounds like this would be a great shooter for the right person. Were the dies found for this gun?

That sounds like a cartridge I was thinking about for one of my 93 Spanish Mausers. I have a Numrich barrel for a small ring Mauser that is .310" bore and chambered for the 7.62 X 39. I want it for shooting cast only.

[gunshot98]

Thanks to Screwbolts, Rifle 57, and Leadman for all your help. Rifle 57, I'm going to talk to my friend about what you said, and help him get this project going. He is excited about the info yall have provided. Thanks so much and will let yall know how it comes out. Steve

[Rifle 57]

OK Steve. I am glad we all could help you out. We will be interested how it turns out.

[biffj]

as a note here....30 BR, 7BR and 6 BR are all 1.5" cases.

Frank

[azrednek]

Seems to me in one of the older Cartridges Of The World books by the original author Frank Barnes. Barnes experimented with the 308 cut to various lengths. If I recall correctly as it has been 25+ years since I read it. Barnes settled on the 308 cut to 1.5. The US Military experimented with the 1.5" cartridge I believe for a suppressed sniper rifle in the Viet Nam era.


I'm sure somebody here has read it as well. If so please chime in here as I may have the facts wrong.

[biffj]

I think you're right. Barnes did do a lot of experimenting with the 308 in various lengths. I think he is responsible for the 30 benchrest which spawned the 6BR and the 7BR as well as my favorite the .338BR which we load primarily for subsonic use with 300gr bullets at 1050fps. It works very well. The 1.75" case might be a bit too big for the subsonics in these smaller cals but could be a real hammer for some supersonic loadings.

Frank

[azrednek]

Not to jump to far off of subject. Barnes also made a subsonic 500gr from a shortened 458 belted mag. It was assembled in a US arsenal and unofficially used in Nam. Barnes claimed to have the only known US GI sample of the experimental cartridge. If I recall correctly is was used in an altered 03 Springfield. Barnes never says but reading between lines sounded like a CIA project.

[Budzilla 19]

Gunshot98, if you still want the original .308 x1.750" caliber I have some Remington BR full length brass, this should help with case-forming for sure, as this was basically 308 brass with thinner walls to allow case forming to 6 and 7 BR from 308 brass! Also this stuff had small primer pockets, if I remember correctly. PM me, we'll figure out something. Thanks

[Rifle 57]

I think you could use some Lapua 6.5x47 brass also and you would only be pushing the shoulder down around .100 and it would be a little easier to make.And it also has small primer pockets.