.300 H&H mag vs .300 Wby mag

[Fly320s]

Can a rifle chambered in .300 H&H magnum safely fire a .300 Weatherby magnum cartridge?

My dad is passing on his Winchester Model 70 in .300 H&H to my brother. I have temporary custody since I delivered it halfway to my brother. I noticed that the rifle is chambered in the H&H mag, while the ammo he sent is .300 Weatherby.

So, what's the verdict? Is this a normal/proper action or something to be avoided?

Thanks.

 

[Onmilo]

OH NOooooo!!!!!!
Weatherby and H&H in no way interchange.

It will take some doing but you should be able to come up with the proper Holland and Holland cartridges.
Dealer may trade for the Weatherby's if they aren't reloads.

 

[steveno]

considering the shape of the 300 wby I doubt that it will even chamber in a 300 H & H chamber. that being said buy the correct ammo and not worry about it. if in doubt take it to a gunsmith to be sure

 

[Samuel_Hoggson]

M-70

It is entirely possible that this M-70 was rechambered to .300 WBY. A chamber cast will tell the story. Of course, if a .300 WBY round will chamber it is a certainty that the chamber was altered. You still need to know for certain if the chamber is .300 WBY.

Remember, most all .300 WBY data is for free-bored chambers. It is possible, but unlikely, that a rechambered M-70 will have a proper freebore section. Again, you need to know. If it is not free-bored you must reduce powder charges several grains.

If your brother is very, very lucky the gun will be an original M-70 with unaltered .300 H&H (often stamped .300 Magnum) chamber. But a M-70 in .300 WBY would still make for a very nice "shooter". The .300 WBY is one of my favorite calibers, and has accounted for the great majority of game I've taken.

Sam

 

[Gordon]

"The .300 WBY is one of my favorite calibers, and has accounted for the great majority of game I've taken. " Ditto, though the .300 H&H would be adequate and I would certainly NOT rechamber to Weatherby in this day and age!

 

[Fly320s]

Thanks for the info.

My dad told me last night that he bought it new in 1961 for $109, then "30 to 40 minutes later" had it rechambered to .300 Weatherby. Too bad for that, but at least I know the correct chamber now.

 

[Bwana John]

It would be nice to remark the barrel to the correct caliber.

 

[HankB]

These days, it's SOP for a gunsmith rechambering a rifle to mark the new caliber on the barrel . . . it may even be a BATF regulation. You might consider having this done.

If you fire a .300 H&H in a .300 Wby chamber, it should fireform to Wby dimensions since the Wby IS basically an improved H&H. (Ditto for a .300 Win Mag fireforming to the larger cartridge, but those cases end up with just a sliver of neck remaining. Judging from the brass I find at various ranges, this seems to be a common practice. I don't recommend it.)

The comment on freebore is correct.

 

[CowboyEngr1]

Ought to check it out anyway.

You have probably gathered this, but just in case - If there is any doubt, it will be best to have the chamber cast by a gunsmith. The 300 H&H has been used as the "base" for many, many wildcats, therefore if it's been re-chambered and the barrel not update-marked, it could be any variant/improved version. If a 300 Wby will chamber, it is likely that is what it was chambered to, but it's best to be safe instead of sorry. In any case, it it's in good shape, it will make a wonderful, classic shooter.

 

[Subby]

Hank,

.300H&H fireforms to .300 Weatherby since they're both full size cases. .300 Win Mag should not, since it's a trimmed full length case.

Sub

 

[HankB]

Subby, you're quite correct. That's why I observed in my earlier post that when a .300 Win is fired in a .300 Wby chamber, there's only a "sliver" of neck left. The shoulder forms OK, but the case is way too short.

 

[Samuel_Hoggson]

OK, so you've got yourself a .300 WBY. Not as desirable as an unaltered H&H, but one heck of a good hunting package.

I would second the recommendation to get the barrel correctly stamped after having a gunsmith verify correct chamber dimensions. The barrel is most likely not freebored. You will probably have the choice of getting the rifling cleaned out to WBY spec, or leaving it. I would leave it, but be mindful not to just use data developed in freebored rifles.........which is about all I've seen. .300 Win Mag data might be a logical starting place (and don't start with max loads). Use a chronograph, pay attention to cases, etc.

As for brass .300 WBY brass is not so hard to find as when I was a kid, so I wouldn't bother to fireform H&H brass. Heck, H&H brass will likely be harder to get nowadays.

Sam

 

[24kshooter]

Too bad - your dad took what is now a somewhat rare $1000 plus desirable rifle and turned it into a $500 also ran.

 

[CaptainCrossman]

old thread, worth reviving.

when Roy Weatherby invented the 300 Weatherby Magnum, he made brass cases for it, by fire forming 300 H&H brass, in the 300 Weatherby Magnum chamber.

That was the standard way to make brass for a 300 Weatherby Magnum, until the proprietary Weatherby brass became more easily available on the commercial market.

The 300 H&H is the parent case for both the 300 Weatherby Magnum, and the 300 Winchester Magnum.

A shooter can also fire a 300 Winchester Magnum round in a 300 Weatherby chamber- and it will fire form the case as well, but the necks will just be a little shorter. Using 300 Winchester ammo to fire form will sacrifice accuracy, as the shorter case neck, will make the bullet jump a bit further before it contacts the rifling.

Once a 300 H&H or 300 Win Mag case is fire formed to the 300 Wby Mag double radius shoulder, it will no longer chamber in a 300 H&H or 300 Win Mag rifle. The Wby case has a taller, wider shoulder- that is how Roy Weatherby gained the extra powder capacity. He basically "blew out" the 300 H&H case.

In Winchester's case, for the 300 Win Mag, they shortened the case, lowered the shoulder, and used faster, more efficient powders that were available at that time. The 300 Win Mag was designed about 10-15 years after the 300 Wby Mag, and the 300 H&H was designed in the 1920's.

As time goes on and powder technology advances, the firearms mfrs. can get the same or more velocity, from a smaller case. Such as the 45 ACP compared to the old 45 Colt.

 

[GlockNation]

Truth

...is stranger than fiction.


My dad told me last night that he bought it new in 1961 for $109, then "30 to 40 minutes later" had it rechambered to .300 Weatherby

 

[Lloyd Smale]

just another reason someone needs to invent a time machine!!

 

[SaxonPig]

Bummer. Took a couple grand off the value with that chamber reamer.

 

[Water-Man]

But made it more effective.

 

[lefteyedom]

Nothing wrong with the rifle you have. The loss of value this rifle suffered by being rechambered would only be realized if you sold the rifle. By keeping it and using it there has been no loss in value.

I must agree that be chamber needs to be casted and freebore checked. Have the barrel stamped 300 Weatherby...

Of course I would be glad to double your dad investment and give you $220 for it,,,

 

[Pete D.]

value

There are a couple of comments about ruining the value of this rifle - or at least lowering its value by altering it. I don't see it quite that way.
The rifle was bought more than 50 years ago for $109. It is, modified or not, worth more than that now.....a pre-70 Winchester chambered for the Wby. 300. Not bad at all.
No way that it could be known in 1961 that Winchester would change in 1970 or that the hot Wby chambering would end up as less desirable. Hindsight is 20/20.
Pete.

 

[CaptainCrossman]

May 9, 2005, 08:53 PM #2
Onmilo
Member
Join Date: July 26, 2004
Location: Illinois`
Posts: 7,848
OH NOooooo!!!!!!
Weatherby and H&H in no way interchange.
It will take some doing but you should be able to come up with the proper Holland and Holland cartridges.
Dealer may trade for the Weatherby's if they aren't reloads. end


old thread but needs to be cleared up, lots of misconceptions here

If you have a 300 Weatherby chambered gun, you can safely shoot 300 H&H in it. This was the standard way to form 300 Weatherby brass, until Norma, etc. started making enough of it to supply commercial demand. You can also fire a 300 Win Mag in a 300 Weatherby. It will fire form to the chamber and the result will be a short neck on the case.

There was also nothing "ruined" by rechambering the gun to 300 Weartherby. It actually made the gun more versatile. It can still shoot the 300 H&H ammo just like before. Only the fire formed case will then be shaped like a 300 Weatherby case after firing it. The only downside is, reloading it again to 300 H&H, would result in working the brass more than usual. This may affect brass life, but they are so close that it may not even matter.

Being the 300 Weatherby is a more powerful cartridge, nothing lost.

Basically anyone who owns a 300 Weatherby, also got a 300 Win Mag and 300 H&H included, free of charge. It is basically a multi-cartridge rifle, but the "powers that be" don't advertise that. Otherwise they'd sell 1/3 as many rifles.

That's why I'd never pay big for a 300 H&H or 300 Win Mag. May as well buy a 300 Weatherby, and you get all 3.

this was also a common gunsmith and trapper/hunter trick up north in Canada and Yukon, etc. at one time. If you had a 303 Savage, have a 30-30 reamer run in it, then it would shoot both 303 Savage and 30-30 Winchester. This way if one ammo was scarce or unavailable, it could shoot the other.

cartridges that are very close in size like that, it can be done. No different than shooting a 38 special cartridge, in a 357 magnum pistol. Or shooting a 44 special or 44 colt or 44 russian, in a 44 magnum pistol.

If the case headspaces on the rim, or in this case the belt, the case just fire forms to the chamber. The caliber is the same. I'm not recommending it as the norm, but if need be, it can be done. If I saw boxes of 300 H&H or 300 Win Mag ammo being given away free, or dirt cheap, I'd take them, to target shoot through my 300 Wby Mag. and save some money. Why spend big to put holes in paper.

There's a lot of bs-ing going on with firearms companies, in reality there are many cartridges out there that have identical reloading data specs, when the cartridge cases are different. For instance, there are loads that are the same for 300 Weatherby and 308 Norma Magnum. Exactly the same powder grains for the same bullet. What's what say ? It's the same darn cartridge with different window dressing of brass, when loaded with that powder and bullet.