Custom rifle
- Thread starter Taube94
- Start date
perhaps a weatherby. Do you have a cartridge for the rifle? I guess it all depends on the gunsmith and reamer used.
Is it a magnum bolt face, or lapua mag? Never seen a 378-338 weatherby. The 338-378 has been around for a long time.
You could do two things
Roughly measure bore and measure the boltface.
338-378 is a known cartridge, 338 bore and .580ish boltface
People have wildcatted a 378-300 but I don’t think you have that as it’s not marked as such.
Roughly measure bore and measure the boltface.
338-378 is a known cartridge, 338 bore and .580ish boltface
People have wildcatted a 378-300 but I don’t think you have that as it’s not marked as such.
I would try and find some of his fired cases among his equipment, if it is still available. Lacking that, the chamber cast is the way to go.
Common practice was to indicate the bullet/bore first, then the case.
If this happens to be correct, the cartridge may be based on a 338 case, with .375 bullets.
Could the Smith have reversed it? Maybe?
Suggest you cast the chamber and make certain.
As others mentioned, measuring the bolt face should give you some useful information about the cartridge.
I did find some data for a .375-338, referred to as a ".375 Belted Newton" and ".375-338 Chatfield-Taylor" developed by R.F Chatfield-Taylor of Manchester, MA. (PO Ackley's Handbook for Shooters and Reloaders, Volume II, page 212 and 213). Load data indicates 300gr bullet velocity of about 2500fps, test barrel length was not stated.
Common practice was to indicate the bullet/bore first, then the case.
If this happens to be correct, the cartridge may be based on a 338 case, with .375 bullets.
Could the Smith have reversed it? Maybe?
Suggest you cast the chamber and make certain.
As others mentioned, measuring the bolt face should give you some useful information about the cartridge.
I did find some data for a .375-338, referred to as a ".375 Belted Newton" and ".375-338 Chatfield-Taylor" developed by R.F Chatfield-Taylor of Manchester, MA. (PO Ackley's Handbook for Shooters and Reloaders, Volume II, page 212 and 213). Load data indicates 300gr bullet velocity of about 2500fps, test barrel length was not stated.
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Probably a wildcat on the "then more popular" .338 Lapua(?) case. There are many options on this, including using a case as small as the .338 Win mag.
As the OP stated, he plans on getting the chamber cast to see what exactly he has. But, necking up a .338 to .375 makes sense if you want heavier bullets, that may be higher BC.
Added: I just realized that rifle has no brake. That's gonna hurt if the case is a .338 Lapua necked up.
As the OP stated, he plans on getting the chamber cast to see what exactly he has. But, necking up a .338 to .375 makes sense if you want heavier bullets, that may be higher BC.
Added: I just realized that rifle has no brake. That's gonna hurt if the case is a .338 Lapua necked up.
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True, but some of these 'extreme' shooters were wildcatting new cases within a year of their release. Lapua released the .338 commercially as soon as the U.S. dumped the experiment. That was back in the early/mid eighties.
Ten years ago there was a thread on it:
Funny, I followed some of the threads on this and "Hammer Bullets" came up. Pretty interesting how this cartridge is coming up.
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