.375-08?

seems a little optimistic. Hodgdon's data shows that a 9.3x62 can really only be expected to deliver about 2250 with a 300 grain bullet
 
If you want a short action .375, try the 375WSM. I know some guys have done it.

I think a 375-06 is more practical, though. And a loaded down 375 RUger would be the bomb, of course. ;)
 
The one problem you might run into is how much shoulder is left with the .375.

I know the 358win doesn't have much shoulder left. The 358win pushes a 250gr partition at a little over 2200fps.

The 338fed pushes the 225gr pills at between 2400-2500fps. Not sure what you would get with the 250gr bullets which would have basically the same sectional density as the 300gr in .375

I would guess you would get 2000-2100fps with the 300gr .375.
 
Gatehouse said:
I think a 375-06 is more practical
Click to expand...

FWIW I looked in my old wildcats book and it listed the 375 Whelen as doing about 2185 with a top load.

Far as the shallow shoulder goes, if a guy is real careful when sizing there should be no trouble, the 9,3x57 has a smaller shoulder but it works fine and they also went up to 10,75 with that case! The 308 case has a much straighter body.

I wonder if anyone ever necked a 284 Win up that far.
 
Noel said:
FWIW I looked in my old wildcats book and it listed the 375 Whelen as doing about 2185 with a top load.

Far as the shallow shoulder goes, if a guy is real careful when sizing there should be no trouble, the 9,3x57 has a smaller shoulder but it works fine and they also went up to 10,75 with that case! The 308 case has a much straighter body.

I wonder if anyone ever necked a 284 Win up that far.
Click to expand...

The .375 Hawk is showing mid 2300's - although I suspect it is running quite a bit higher pressure, in addition to some extra case capacity, compared to the .375 Whelen.
 
These are a couple of dummy rounds I made up a while back. I ran the cases through a succession of dies including .338, .358, .366 and finally, .375.

The cartridge on the left is a .375-308 Win and the cartridge on the right is a .375-303 British. Both are loaded with 300 gr bullets.

There's lots of shoulder on the .375-308 Win and the .375-303 British will headspace off the rim.

c76b3278.png
 
1899 said:
The .375 Hawk is showing mid 2300's - although I suspect it is running quite a bit higher pressure, in addition to some extra case capacity, compared to the .375 Whelen.
Click to expand...

Actually, looks like 2400 there!
Quoting Dave Scovill on his case design:
Top loads with the 300 grain Hornady roundnose sneak up on 2400 fps with all the powders listed. Of the lot Reloader 15 showed remarkable shot to shot consistency. Some velocity variations were less than 10 fps for five shots. At 2397 fps the big bullet packs nearly 3840 ft-lbs of muzzle energy
Click to expand...

His case started out as a 375 Whelan, then an improved whelan and then a 9,3x62 necked up and then:rolleyes: a modified 9,3x62 using a standard 30-06 web diameter brass. (9,3x62 is slightly bigger).

I thought for sure I had 375-308 data in that fat old book of mine but looks like just 33-308 AKA 338 FUD.

At any rate necking up the 308 would make a fun cartridge. I would likely use the Hornady 270gr Round nose for the task. Made for 375H&H velocity and work load it would sure penetrate!
 
Mauser98 said:
These are a couple of dummy rounds I made up a while back. I ran the cases through a succession of dies including .338, .358, .366 and finally, .375.

The cartridge on the left is a .375-308 Win and the cartridge on the right is a .375-303 British. Both are loaded with 300 gr bullets.

There's lots of shoulder on the .375-308 Win and the .375-303 British will headspace off the rim.

c76b3278.png
Click to expand...

Middle is a 7.62x39 I guess?

That looks like a fair cartridge even with 300 grain bullet. Does the 300 grain bullet intrude the powder capacity much? Is the OAL same as a regular .308?

I wonder what sort of velocities one could get from the 235, 270 and 300 grain bullets, and what sort of pressures would develop.

150 grain 7.62x39 gets 2100 fps. Perhaps the 300 grain in a .308 case might achieve similar results... 235 grain at 2400 would certainly be no slouch. Would out-punch a .30-30 by a fair margin.
 
philthygeezer said:
This could be a neat cartridge if it could push 300 grain dangerous game bullets at 2250 fps. Better than a guide gun maybe.

So is it doable?
Click to expand...

It's been done quite a few times, there's even dies available. From what I've read, guys were getting just over 2000 fps with a 270 gr. in a 20" bbl. I would assume that most 375 bullets are too long for the 308 case and are also meant to expand at higher velocities. Going to the 225 grain bullet serves little purpose in that caliber. I can't see any advantages or even matching performances of current big bore brush guns

A better attempt at something newer may be to neck up 300 WSM or RCM cases to 375. More shoulder to headspace on and should be more powder volume/velocity.
 
bearkilr said:
It's been done quite a few times, there's even dies available. From what I've read, guys were getting just over 2000 fps with a 270 gr. in a 20" bbl. I would assume that most 375 bullets are too long for the 308 case and are also meant to expand at higher velocities. Going to the 225 grain bullet serves little purpose in that caliber. I can't see any advantages or even matching performances of current big bore brush guns

A better attempt at something newer may be to neck up 300 WSM or RCM cases to 375. More shoulder to headspace on and should be more powder volume/velocity.
Click to expand...

Looks like Whelen did it with the .375-06: 300 grains at 2100 fps with that case.

http://en.wikipedia.org/wiki/.375_Whelen_%28.375-06%29

Bullet (grs.) Powder / (grs.) MV ME
200 SP IMR4064 / 58.0 2450 2265
235 SP IMR4064 / 60.0 2475 3205
270 SP IMR4064 / 57.0 2380 3400
300 SP IMR4064 / 52.0 2110 2975

The thought was a mild-recoiling standard or short action length medium bore that could be done with just a rebarrel from ordinary rifles. I wonder whether a 270 grain at 2000 fps or a 300 grain at 2100 piques anyone's interest.

The .375-06 or .375 Whelen could match the newer heavy .45-70 loads while having better ballistics perhaps.
 
philthygeezer said:
Middle is a 7.62x39 I guess?

That looks like a fair cartridge even with 300 grain bullet. Does the 300 grain bullet intrude the powder capacity much? Is the OAL same as a regular .308?

I wonder what sort of velocities one could get from the 235, 270 and 300 grain bullets, and what sort of pressures would develop.

150 grain 7.62x39 gets 2100 fps. Perhaps the 300 grain in a .308 case might achieve similar results... 235 grain at 2400 would certainly be no slouch. Would out-punch a .30-30 by a fair margin.
Click to expand...

7.62x39 - correct.

I didn't check for bullet intrusion. The oal ended up at about 2.74".

Here's a link to a thread on the 24hourcampfire that may be of interest.

http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/5015382/Re_375_308_Velocities
 
Mauser98 said:
7.62x39 - correct.

I didn't check for bullet intrusion. The oal ended up at about 2.74".

Here's a link to a thread on the 24hourcampfire that may be of interest.

http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/5015382/Re_375_308_Velocities
Click to expand...

From the thread:

MeltonJD.375-308.01.JPG


(L to R) Factory 270 gr 375 H&H, Factory 300 gr 375 Ruger, Factory 270 gr 9.5 MS, Winchester 300 gr FMJ 375-308, Barnes 270 gr TSX 375-308, Nosler 260 gr PAR 375-308, Nosler 260 gr AB 375-308, Barnes 235 gr TSX 325-308. All 375-308 bullets seated to 2.80 inch overall length.



MeltonJD.375-308.02.JPG


Original 9.5 MS with 270 FMJ shown on the left. Seating depth comparisons for 375-308. (L to R) 300 gr FMJ, 270 gr TSX, 260 gr PAR, 260 gr AB, 235 gr TSX. Overall length of the 375-308 rounds is 2.80 inch.



MeltonJD.375-308.03.JPG


Cannelures lined up for comparison. (L to R) 300 FMJ, 270 TSX, 260 PAR, 260 AB, 235 TSX, 375-308, 9.5 MS, 375 Ruger, 375 H&H.
 
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