I have a winchester M70 Stainless Classic in 375 H&H that I am planning on getting some custom work done to. I'm having it put in an ultra light kevlar stock and having the barrel turned down to lighten it up. I'm shooting for a completed rifle in the 8lb range loaded with scope. As it sits right now its over 11 lbs. I have heard a lot about the 375 weatherby and wondered if it would be worth having my rifle rechambered while I was at it. Does it really provide that much of a performance boost? Can you shoot regular 375 H&H out of it in a pinch much like you can with ackley improved cartridges? Just looking for some advice from you big bore guys. THanks

If you don't mind the recoil, go for it. I would aim for 8.5lbs myself, but either way you'll notice when you touch one off. What barrel length are you considering?

I think John S. and Rip both have lots of .375 Wea. experience. This is a great forum for your questions.

Yes, you can shoot regular 375 H&Hs out of it if you want to. The 375 Wea is basically a 375 H&H improved. Depending on many factors, the 375 Wea does provide an honest 150-200fps velocity increase over the 375 H&H. Put another way, you'd get a flatter trajectory with it shooting 270gr bullets (circa 2850fps) than a .338 win. mag. shooting 250gr bullets (circa 2750fps). That would make a great Brown Bear stopper and double for Moose, elk and the odd stray African Lion from the local zoo...it would also do it all at ranges farther than most would even consider shooting dangerous game at.

I'll step aside and let the real experts chime in here.

I had my stainless mod 70 drilled or rechambered to 375 wby. I really like it, as C.lefty says it shoots flatter and 400 yards is easier than before with the H&H. Mine weighs close to 9 lbs when loaded,it has heavy detachable rings and a Leupold 3x9 scope. With Weatherby factory loads it was chronographed at 2770 with 300 grain partitions. It is still strange to me to shoot H&H ammo which fireforms into a short WBY case, but I have done it many times .Saeeds handload page is a good place to start.I hate recoil and tO me the 375Wby feels about like a 12ga 3 inch magnum,hard but not that bad. Best of luck Ben (rug)

My goal is to have a rifle light enough to carry all day, even when wearing snowshoes, or waiders when trudging thru knee deep water will moose hunting. I'm not to concerned with the recoil, I had a 7 lb 338 win mag that kicked pretty fearce. It was a joy to carry around while hunting, and I do most of my practice from feild positions anymore anyway. I only do initial sight in from the bench using my past recoil pad. If its too brutal I'll get a muzzle break put on it, I'd rather an easy to carry all day rifle than an easy to shoot all day rifle that was too heavy.

quote:

Does it really provide that much of a performance boost?

quote:

Canadian Lefty
the 375 Wea does provide an honest 150-200fps velocity increase over the 375 H&H.

This is about right.....or put another way its about as much faster as a major league baseball pitcher can throw a baseball

You be your own judge as to how much better this is.

Yep, it is a great cartridge and one I am very happy to have in my battery. It may not be suitable or appealing to everyone, but that's the case for most cartridges. It does kick more than a regular 375, but you do gain the 150-200fps with the heavy bullets. If you intend to use 260gr bullets it doesn't really offer much advantage. A big advantage I see it having is the ease of loading to achieve the top velocities. The old H&H is not a real roomy case so you end up wih heavily compressed loadings. With the Wby there is plenty of room and you have a wider choice of powders that are very suitable. You can easily shoot H&H ammo in it if the need arises, but for normal use I'd buy the Wby brass because it is a full 2.850".
Years ago I owned a M70 in 375Wby that weighed about 7.5 pounds, and that was a real handful to shoot. It had a fast barrel and I could get nearly 2800fps with 300gr Noslers. I eventually rebarreled it to 416 Rem. but the interest in the Wby never died so I eventually built another. Despite what the detractors have to say about the improved 375s, they are useful and make a good cartridge even better, IMO.

My view is that unless you are going to be shooting beyond 300 yards, the extra velocity of the 375 Wby is not meaningful. But beyond 300 yards that extra velocity helps to flatten the trajectory a bit. As for killing power on game, you will not be able to tell the difference, except that the H&H will penetrate more deeply because the bullets will not expand quite so quickly.

500Grs-
After seeing a very large amount of game killed with a 375Wby and my buddy's 375 Ackley, I believe I have a slightly different view of what these cartridges can do, vs the H&H. I've hunted it several times too and have enough experience to know what it can do as well.
How much actual field experience on all sizes of game with the 375Wby or Ackley do you have to base your statements on? Your post is basically the same bit of copy that everyone uses to berate these cartridges.

John S-
I have used .375 AIs & .375 H&Hs , mine and friends. The rifles were (Remington Safari, before and after, 4 Brno zkk 602s, before and after, Voere Titan, before and after and finally a Sako, before and after). The extra feet per second made them powerhouses! Absolute thumpers!! The differance has to been seen to be believed!! When you shoot a .375 H&H, there is a BOOOM, and animals fall. With the AIs there is a CRRAACK, that only speed can produce, animals fall with more authority!
E.g. After the alterations and loads were worked up, we looked for moving targets in spring bear season. The first bear was a lung shot at 56 yards, he dropped at the shot and there was a thick mass of pink foamed blood, beside it. The bullets were 270 Speers & 250 Sierras. The jist, is I know the differance. The differance is a big push for recoil in .375 H&H, and sharp sudden recoil in .375 AI. The recoils also will let you know about the power differance as well.

I'd keep it as a .375 H&H. Nothing against a .375 Weatherby but I think a .375 Weatherby is the same as a .375 Ackley Improved only with rounded shoulders. I don't think you would gain anything by rechambering to any improved .375 unless you intend to only use ammunition you reloaded yourself.

Richard

the bear, i have been also thinking of chambering one of mine to wby, is there someone that can do this in ak and who are you going to turn down the barrel? is this spendy?

Unlike John I see a decent increase in speed with the lighter bullets from re-chambering my Winchester . An easy 150 fps and in some cases 200 .

What I have seen is that the Weatherby chamber functions better @2950 with 260/270 gr slugs than the H&H did at 2800 fps.....less case stretching and cleaner extraction . I think the H&H is at it's best when kept at standard factory pressure levels for around 2700fps/270 gr bullet . I also found one powder that would push the 260 accubond to 3000 fps with no problem and good accuracy . Should be a very good long range elk load .

I can't detect a whole lotta difference in recoil or muzzle blast between the Weatherby at 2950 versus the H&H at 2800 . And for whatever it's worth , the Weatherby 300 gr Nosler factory ammo kicks up 2780 fps at 15 feet in my rifle .(24 inch barrel) . That puts it awful close to it's factory rating of 2800 fps at the muzzle .

John S., has something been eating at you lately??

From your post it does not sound like you have actually compared the 375 Wby versus the 375 H&H on game, instead relying on the assumption that the 375 Wby is better because it worked well.

I've had several .375s only one Ackly. Definatly a major performance increase. As far as 4-500 yrd. shots, if loaded to full potential with heavy bullets I seriously doubt you're going to want to torch one off from prone. More power yes, way longer reach, hard to say. Better brass life and looks cool at the range. I'm back to a plain old H&H but this is one imp. round that goes way faster than it's parent case.

I always liked the 375 H&H but Having the rifle rechambered is just more practical ,as you can still fire factory H&H, or the WBY. I have two loads with the same point of impact,no re-sighting between them. Does the WBY work better on game from about 100 yards and beyond yes. Up close, too hard to tell they are both Very Fatal . You loose nothing and gain more powder, besides the rechambering can be done for about $100-150.

I would leave it as is, a .375 H&H Mag. I've been able to get an honest 2700 fps out of mine with H4350 and 300 grain Hornadys (26 1/4" barrel) and if you don't reload, try the Hornady Heavy Mag ammunition. It will give you that same 2700 fps with that bullet weight. It is easier to find this ammunition than the .375 Weatherby too!

quote:

Originally posted by 500grains:
John S., has something been eating at you lately??

From your post it does not sound like you have actually compared the 375 Wby versus the 375 H&H on game, instead relying on the assumption that the 375 Wby is better because it worked well.

500grs-
No, I was just inquiring if you had ever used a 375Wby or 375Ackley enough to have a basis for comparison against the H&H round. When someone posts a statement or two such as you did, I just like to know if it is from their own experience or are they just repeating something they have heard. I believe if you will read my post again you will see that I did say that I have used and/or seen used all three rounds mentioned, and not on just one or two animals. Was that not very apparent to you? Yes, I have compared them in the field, on several occasions and on several different animals.
In my own experience, there is a difference, and what you posted was not what my own experience showed.
The 375Wby is not for everybody and I have no problem with that. Some don't like the extra recoil generated by the improved versions. Many hunters want to hunt with the classic, and that's fine too. Many do not believe in higher velocity for various reasons.
So, have you used the 375Wby on any game? If so, did it's performance cause you to make the statements about it that you did?

You can fire the standard H&H in a Weatherby or improved but it's not a good way to make brass as the expansion web is weakened by the metal being pushed forward during fireforming.

As to the 375 Weatherby vrs the Holland version I would skip over the Weatherby unless the rifle had some special purpose as long range shooting as mentioned above.

I would choose between a 9.3, 375 H&H or some 416 cartridge instead.

I have both a H&H and Improved .375 and the larger case kicks quite a bit more. Get what you want however as the 375 Weatherby is not bad at all.

I've always wanted one. Even though I dearly love my 375 H&H, I did a lot of research and compiled quite a bit of anectodal data on both cartridges. I spoke to Craig Boddington about it, as it's one of his all-time favorite cartridges. Were I to make a custom rifle, the 375 would probably be my choice. I think the extra "flatness" would come in handy. jorge

Ditto John S,
I hunted Kodiak twice with a .375 Wby, cut some deer in two with it on Kodiak, chased King Kong with it there (looked like a 13-footer running into the willows 300 yards away after a 2-mile glass and stalk) ... he got away, and my resident drawing permit for Jap Bay went to waste.

But I feared no evil when armed with a .375 Weatherby.

Due to the practical aspect of using .375 H&H ammo in it, in a pinch, it is the ultimate .375 Rifle.

The heavier bullets give it an advantage more so than the lighter bullets, compared to the .375 H&H. You can get at least 200 fps extra with 300 grainers, and more like 300 fps extra with 350 grainers. But 300 grainers are all anyone needs. KISS.

Flat nosed solids will not penetrate less at higher speed. Controlled expansion bullets like the North Fork soft will work better at higher speeds too.

After doing the page on the .375 Wby for Saeed's reloading pages, I discovered New H4350 Extreme (a short cut extruded). With 300 grainers just start at 80 grains and work up to Nirvana.

Be sure to get the 2001 Throat spec., not the sloppy old 1945 throat that is way too long and wide.

The new freebore is only 0.3700" long and .3755" diameter.

Yes - 375 Weatherby!

If memory serves me right Warren Page hunted all over the world with a 375 Weaterby. He is often remembered for his 7mm Mashburn Magnum "Old Betsey" but there is a fair amount writen about him using the 375 also.

Bill Jordon also was a great believer in the 375 Improved. His was a 375 Mashburn in which he wrote he could shoot 375 H&H, 375 Ackley, and 375 Weatherby rounds as well as his 375 Mashburn ones.

This 375 weatherby is starting to look better and better. I'm betting a 300gr Barnes TSX @ 2800fps would be a heck of a good load.

Is there a difference in feeding between the two? The H&H has to be one of the smoothest feeding cartridges available. Going to the Weatherby does that usually require some work on the rails or magazine box?

quote:

Originally posted by Prewar70:
Is there a difference in feeding between the two? The H&H has to be one of the smoothest feeding cartridges available. Going to the Weatherby does that usually require some work on the rails or magazine box?

The .375 weatherby feeds exactly the same as the .300 weatherby and the .340 weatherby. If you can feed either of these you can feed the .375 as well...it's the same dimensions.

quote:

Originally posted by Prewar70:
Is there a difference in feeding between the two? The H&H has to be one of the smoothest feeding cartridges available. Going to the Weatherby does that usually require some work on the rails or magazine box?

The 375 AI sharp shoulder on my Whitworth had a tendency to snag when feeding. Just a little hesitaion, never a full jam. That may not happen in your gun.

I think it's a good round but having had one, I'm not impressed enough to build another. But I wouldn't pass up a good deal on a used one either.

8 lbs is going to get your attention, though. You may end up loading it back down to H&H levels just make it more shootable. If so you wouldn't be the first.

My current 375Wby feeds perfectly, as did my previous one. A qualified gunsmith can take care of any feeding troubles when he does the rechamber job.
Getting a 300gr TSX to hit 2800fps in anything less than a 26" barrel is probably unrealistic. That's a very long bullet and I have my doubts it can be done at all with sane loadings. You can get 2700fps easily with it, and thats 200fps more than any 375H&H will ever get with that bullet.

quote:

Originally posted by Prewar70:
Is there a difference in feeding between the two? The H&H has to be one of the smoothest feeding cartridges available. Going to the Weatherby does that usually require some work on the rails or magazine box?

I have converted 3 different factory .375 H&H rifles to .375 Weatherby (Whitworth Mark X, Winchester M70 Classic stainless, and CZ 550 Magnum Safari) and never had any feeding issues. Just polish the ramp and rails smooth and it should work fine if the .375 H&H worked through it to start with. A .375 Weatherby reamer does clean up the .375 H&H chamber without any need to set back a thread. Not so with the .375 RUM, and that one needs whole new box, follower, and spring to convert some rifles ... off topic.

quote:

Originally posted by John S:
My current 375Wby feeds perfectly, as did my previous one. A qualified gunsmith can take care of any feeding troubles when he does the rechamber job.
Getting a 300gr TSX to hit 2800fps in anything less than a 26" barrel is probably unrealistic. That's a very long bullet and I have my doubts it can be done at all with sane loadings. You can get 2700fps easily with it, and thats 200fps more than any 375H&H will ever get with that bullet.

Getting the .375/300gr TSX up to 2800 fps in a 26" barrel should work if you have the 3.85" long box of a CZ 550 Magnum or such. Load that bullet to 3.75" or longer, wherever the cannelure for crimping allows. I haven't tried it yet, but it is on my list of TOOO-DOOO's. The 2001 Weatherby throat will allow it just fine.

The Weatherby factory loads with 300 grain Nosler partitions loaded for 3.6" magazine boxes will get 2800 fps in a 26" barrel just as the ammo box claims.

As 500 Grains said, if there is something to be gained it's at distance and not much, at that. I like the .375 Weatherby, just fine, but there's nothing it will do afield that a 26" .375 will not. While the benefit of an inch or so flatter trajectory @ 400 yards sounds good, most shooters will not do satisfactory work at such distance, due to the extra recoil. Those few who can, might consider the .378.

I had a 375 Weatherby once it was built on a FN action. Anyhow I shot a nice cow elk with it that year I also broke my nose that day it happened as soon as I pulled the trigger on that damn thing I was shooting up hill. Since once wasn't good enough I saw the cow moving and I shot again you guessed I was really bleeding by then. I almost knocked myself out. Anyhow I traded it off about a year later maybe sooner but I never shot it again after that.

John

Nick-
I guess some of us just believe in the benefits of higher velocity. No question that 375H&H can handle the field work, its just a question of how well for the individual. I really don't care about the long range side of it, it's what happens under 250yds that I get interested in. I think Roy called it hydraulic shock. I don't know what it is but it sure works for me.

If a slight velocity increase is the only benefit of the rechambering, then would it not be more prudent to leave the chamber as a .375 H&H and just buy Hornady Heavy Magnum or Federal High Energy factory ammo for it?
You get the increase you're looking for without changing the chamber...

As for a weight difference...between 8 and 8 1/2 lbs., why not just tape a candy bar to the rifle for the extra weight when needed?

quote:

Originally posted by BusMaster007:
As for a weight difference...between 8 and 8 1/2 lbs., why not just tape a candy bar to the rifle for the extra weight when needed?

Bus, if you think I'm gonna risk crushing a perfectly good candy bar for a 66" kudu at 400 yards, you're nuts!

I absolutely love mine. The 375 Weatherby is a very well balanced cartridge. With the 270 or 300 grain bullets it is basically a scaled up 30-06 shooting 165 or 180 grain bullets.

The biggest advantage of the 375 Weatherby over the H&H is when you are loading fully or partially monometal bullets. Enough boiler room to get them moving without spiking the pressures.

lawndart

The Weatherby cartridges seem to feed about as well as any belted magnum . People claim the rounded off Weatherby shoulder is just a gimmick , but I beleive it will tend to feed better than any AI type cartridge.

At any rate , there is zero differnce in feeding in my re-chambered rifle between Weatherby and H&H cartridges .

The .375 Weatherby is a great round & if you can shoot .375 H&H ammo if you ever haved a need to do so.

Not to hijack this thread, so please feel free to P.M. me, but if you have a 375 Wea., do you need the 416 rem. mag.?

Put another way, does the 416 rem. mag. offer enough of a difference against dangerous game for it to be considered over a .375 Weatherby?

quote:

Originally posted by CanadianLefty:
..... does the 416 rem. mag. offer enough of a difference against dangerous game for it to be considered over a .375 Weatherby?

YES and it will do for most plainsgame too.

Very interesting. I have a dilemma- DO I need to fill a gap between a 300 win. mag and a .416 rem?