Surely this combination has been tried and I can't think of it's name, either necking a 375 H&H down or necking the 300 H&H up to 338. Has this been done and what is it called. Is there something else out there close to it?

quote:

Originally posted by Prewar70:
Surely this combination has been tried and I can't think of it's name, either necking a 375 H&H down or necking the 300 H&H up to 338. Has this been done and what is it called. Is there something else out there close to it?

That's the .375 Taylor (.338 case topped with a .375-caliber bullet). It seems that this wildcat is getting popular, since it almost duplicates the .375 H&H's ballistics from a much smaller case.

I posted a link to the .375 Taylor page on this forum. Just look for the post ".375 Wildcat" on this forum.

I thought of that, but I was thinking of the 375 H&H case necked down to 338. I think that would be a longer case than the 338. Maybe close to a 338 RUM, but the H&H case is still different I believe. A 338/375H&H.

After looking at my reloading books, I guess it's basically an 8mm Rem Mag, except that it would shoot 338 diameter bullets. Still never really heard anybody talking about a 375 necked down to 338.

I believe Elmer Keith did that one. May have used .333 bullets though. Basically a bit milder 340 Weatherby.

Well, if the 8mm is close, the .340 Weaterby is closer! I know it has sraight walls and sharp(Venturi) shoulders, but so does the 8mmRemMag.

quote:

Originally posted by Prewar70:
I thought of that, but I was thinking of the 375 H&H case necked down to 338. I think that would be a longer case than the 338. Maybe close to a 338 RUM, but the H&H case is still different I believe. A 338/375H&H.

Sorry about that, I just realized I had misread the original question.

This is close to the .338 Jarrett - an 8 mm mag case necked up to .338 then fire-formed into an improved configuration. I have a .300 Jarrett. Ballistics of the Jarretts are identical to the Weatherby's, just no free-bore to get there. I use .300 Weatherby data to reload.

Prewar70 Elmer Kieth and his buddies were playing with .333 calibre wildcats. They had one on a 30-06 that was called the 333OKH and on 375 case without the sharp shoulder and it was called the 334 OKH . When Winchester brought out the 338 Win they started chambering for the slightly larger bore. Griffen & Howe also had a 35 calibre rifle on a std 375 H&H necked to 35 called the 35 G&H. Sharp shouldered blown out cases such as the 340 Wby were popular because they would hold a little more powder and achieve slightly higher .velocity. The Apex rifle Co. also had a line of calibres that basically used the tapered H&H case (not blown out) with a sharper shoulder. There may have been others as well. Hope that helps.

quote:

Originally posted by Prewar70:
Surely this combination has been tried and I can't think of it's name, either necking a 375 H&H down or necking the 300 H&H up to 338. Has this been done and what is it called. Is there something else out there close to it?

Well, since the .338 holds about the same amount of powder as the .375 H&H case, and one can neck the .338 up to .375" and get essentially the same out of it as from the full-length .375 H&H case, it would be a drill in futility to neck the .375 H&H DOWN to shoot .338 bullets - you would gain nothing except create a case that has to have a longer action & bolt throw to get the same velocities.....

quote:

Originally posted by cobrad:
This is close to the .338 Jarrett - an 8 mm mag case necked up to .338 then fire-formed into an improved configuration. I have a .300 Jarrett. Ballistics of the Jarretts are identical to the Weatherby's, just no free-bore to get there. I use .300 Weatherby data to reload.

No, what you've described, an 8mm Rem Mag. necked up to .338, would resemble the .340 Weatherby more than anything else....

quote:

Originally posted by El Deguello:

quote:

Originally posted by Prewar70:
Surely this combination has been tried and I can't think of it's name, either necking a 375 H&H down or necking the 300 H&H up to 338. Has this been done and what is it called. Is there something else out there close to it?

Well, since the .338 holds about the same amount of powder as the .375 H&H case, and one can neck the .338 up to .375" and get essentially the same out of it as from the full-length .375 H&H case, it would be a drill in futility to neck the .375 H&H DOWN to shoot .338 bullets - you would gain nothing except create a case that has to have a longer action & bolt throw to get the same velocities.....

This is a very accurate statement. I agree.....nothing gained at least ballistically.

quote:

Originally posted by El Deguello:

quote:

Originally posted by Prewar70:
Surely this combination has been tried and I can't think of it's name, either necking a 375 H&H down or necking the 300 H&H up to 338. Has this been done and what is it called. Is there something else out there close to it?

Well, since the .338 holds about the same amount of powder as the .375 H&H case, and one can neck the .338 up to .375" and get essentially the same out of it as from the full-length .375 H&H case, it would be a drill in futility to neck the .375 H&H DOWN to shoot .338 bullets - you would gain nothing except create a case that has to have a longer action & bolt throw to get the same velocities.....

Good points. How much more powder does the .375 case holds over the .338's? I imagine that he would get higher velocity using .338 bullets, but the smaller bore could also increase pressures. Am I wrong on this?

The only advantage I can see over the .375-caliber bullets would be greater SD from the .338-caliber bullets, and maybe a little higher velocity.

Other than that, a wildcat that would make sense would be the .375 Taylor (.338-375), since the .338-caliber case holds enough powder to launch the .375-caliber bullets fast enough to near or almost duplicate the ballistics of the .375 H&H. In this case, the larger .375-caliber bore should somewhat reduce pressures.

The .338 Win. has a case volume of around .314 cu in., and the .375 H&H's is .322 - I imagine if the .375 case were necked to .338", the difference would be even less.....

quote:

Originally posted by Prewar70:
Surely this combination has been tried and I can't think of it's name, either necking a 375 H&H down or necking the 300 H&H up to 338. Has this been done and what is it called. Is there something else out there close to it?

I thought about a .338/300 H&H before. What purpose would it serve? Hell, I don't know. Just to be a unique cartridge I guess. There are plenty of factory rounds in the same boat. I never got any further than this. The one on the right does look kinda cool though.

Terry

Hey that does look cool Will you shoot a bunch of them now and tell me how the velocity compares to the 338 Win Mag.

One late thought, I bet if feeds better than the 338 WM.

My calculations say it should push a 210gr Nosler Part. down a 24" barrel at 2700fps with 65gr of IMR4831 creating 55468 psia.

About 75fps slower than a .338Winmag under the same parameters.

On the feeding issue I'm sure it would have to feed better, but would that alone be worth the 75fps.



Terry

P.S. This is a starting load, so a reply that "I get 3000fps in my .338WM" is irrelevant. actual #'s will certainly differ, but about 75fps is a very good guess.

Oh yea, CH4D sells a .338-.300H&H die set for $72.00 so you wouldn't be the first kid on the block with one.

Terry

I shoot something in the same ballpark, the 350 Rigby. It is essentially a beltless 358/375, though it has a 45 deg shoulder, and is shortened to 2.76", I say essentially because it pre-dates the 375 H&H by 2 years. I achieve an easy 2700 fps with 250 gr bullets, and the gently tapered case feeds very smoothly.

I can't say the excercise would be worth it, as a 338 win mag will do everything a 338/375 will do, and in a factory gun. The longer action argument is really a non issue, as 2.5" and 2.85" cased rounds are built on the same actions.