Log In
November 7, 2015
Offline
triggerhappy said
You probably are right about their return policy, I don’t know, but if I have to pay a gunsmith to do a chamber cast, I doubt they do those free either. Selling the Weatherby ammo at a slight discount shouldn’t be difficult, and who knows maybe I need it. At the end of the day I think I’d save money, and I don’t have somebody handling my rifle, and telling me “that scratch was already there”. I had that happen with my truck.
Respectfully, your math is good but reasoning is flawed. Chambering a round does not necessarily tell you all you need to know about a rechambered rifle with vague markings. It won’t tell you if the chamber is cut correctly or eliminate the possibility of a wildcat chambering larger than the chambered round.
Mike
August 4, 2023
Offline
I would only be concerned if everything was correct or not if the Weatherby round chambered. If it did then I would need to find out more about what was done. If it doesn’t and the H&H does, I’d figure it’s factory. That is my entire motivation with buying a box of Weatherby. If my rifle had some non-factory markings, I wouldn’t test it this way….I probably would not have bought it in the 1st place.
January 20, 2023
Offline
Greg, I understand your desire to avoid having a chamber cast made but with a mystery chamber it really is the only safe way to proceed.
The pre64 Model 70 action does not handle escaping gas well at all – it is not a Remington 700, much less a Weatherby Mark V. The Weatherby cartridge operates at near redline breech pressure and if the case fails inside that slightly modified Mauser action you risk losing fingers and part of your face, not just destruction of the rifle.
Consider the possibility the chamber was poorly cut giving excessive headspace and then abandoned into the market as a bad job. Or was cut without any freebore, which the Weatherby cartridges demand. A badly cut chamber may only stretch cases 5 times out of 6 and let one rupture on the 7th.
Lighting off a 65,000 PSI pressure vessel that cannot withstand the forces without backup from a properly shaped chamber, inches in front of your head, is something that should give a man pause.
Using a live round as a headspace gauge doesn’t work. A chamber that gives a factory round excessive headspace or other lack of support can easily allow the bolt to close over a factory round.
A chamber cast shouldn’t cost more than about $75 to $80 USD – at least here in Texas. A good gunsmith won’t scratch your rifle. Ask for referrals for your area from other WACA members.
That is my sincere advice, for whatever it may be worth.
- Bill
WACA # 65205; life member, NRA; member, TGCA; member, TSRA; amateur preservationist
"I have seen wicked men and fools, a great many of both, and I believe they both get paid in the end, but the fools first." -- David Balfour, narrator and protagonist of the novel, Kidnapped, by Robert Louis Stevenson.
August 4, 2023
Offline
If I owned the subject rifle I would have a chamber cast done, but saying that I would never buy that rifle in the 1st place.
I have heard that many H&H Model 70’s were converted to Weatherby. I don’t know how true that is, or what is meant by “many”. The % that were converted and not identified as Weatherby conversions…. if that is dangerously high then I see your point. Are you saying all Winchester model 70’s that are H&H Magnums should have a chamber cast to find out if they are still H&H?
My prior thoughts were if your Model 70 H&H Magnum without anything but factory script does not chamber a Weatherby magnum it can be considered a factory H&H Magnum. If my thoughts are wrong then word should get out that these Model 70 H&H Magnums should be avoided unless you take it to a gunsmith 1st. Considering that the cost of these pre-64 H&H Magnums is high, the high risk of a botched conversion let alone a well done conversion should become a big factor in any sale, especially an auction where chamber casting results aren’t known. There is a lot of money at stake, and even more important, your safety.
November 5, 2014
Offline
The Model 70s most affected are 22 Hornet, 300 H&H Magnum and 375 H&H Magnum. Usually the gunsmith responsible for the rechambering would mark the barrel in some way, but not always. Especially the H&H Magnums made before 1950, when the caliber stamps were only “300 MAGNUM” and “375 MAGNUM” (no “H&H” or “Weatherby”).
I cannot give an accurate estimate of how often the rechambering was done and not marked, mainly b/c when it wasn’t marked it wasn’t marked. 
But the rechamberings themselves were pretty popular back in the day. I once took a very nice transition 22 Hornet of my Dad’s to the range and after firing extracted beautifully fire formed 22 K Hornet brass!!! No marking to indicate the conversion…
I guess my approach to these guns might be considered dangerous. But we are talking about rechambering (using a reamer to open up an existing chamber), not a conversion, for example from 30-06 to 300 Winchester Magnum. That conversion can be done badly, unnecessarily removing metal from behind the bottom recoil lug under the mistaken assumption that it was needed for the cartridge to feed and inadvertently creating an unsafe gun. Even a chamber cast won’t pick up that disaster in the making!!!
But, after all, the way you MADE 300 Weatherby, 375 Weatherby or 22 K Hornet brass was to fire form it from 300 H&H Magnum, 375 H&H Magnum, or 22 Hornet. Before purchasing, I would check that 300 Weatherby or 22 K Hornet brass would not chamber (I used to hunt with a Weatherby 300 Magnum so have lots of brass), but if not I’d just shoot the gun and see what the brass looked like. I think the only danger in this would be the situation Zeb described, where an incompetent gunsmith cut a sloppy chamber and didn’t use Go, No-Go gauges… But if the larger brass wouldn’t chamber I’ve just assumed that the chamber was factory original.
Maybe I’m just too much of a “risk taker”… 
Lou
WACA 9519; Studying Pre-64 Model 70 Winchesters
April 15, 2005
Offline
I am going to add to what Lou has just discussed… it is neither risky of dangerous to shoot standard 22 Hornet ammo in any rifle chamber that has been altered (reamed) to 22 K-Hornet. Further, just because you cannot fully chamber a K-Hornet cartridge in an unknown rifle, don’t assume that it is still a standard 22 Hornet. There are at least several different variants of the K-Hornet! I know this because I own two different K-Hornet rifles and the cartridges for each are not interchangeable. Each of them have a different neck length and shoulder angle.
Bert
WACA Historian & Board of Director Member #6571L
March 31, 2009
Offline
To add to what Bert said, the Hornet and the K Hornet were both wildcats in the beginning.
January 20, 2023
Offline
Louis Luttrell said
The Model 70s most affected are 22 Hornet, 300 H&H Magnum and 375 H&H Magnum. Usually the gunsmith responsible for the rechambering would mark the barrel in some way, but not always. Especially the H&H Magnums made before 1950, when the caliber stamps were only “300 MAGNUM” and “375 MAGNUM” (no “H&H” or “Weatherby”).
I cannot give an accurate estimate of how often the rechambering was done and not marked, mainly b/c when it wasn’t marked it wasn’t marked. But the rechamberings themselves were pretty popular back in the day. I once took a very nice transition 22 Hornet of my Dad’s to the range and after firing extracted beautifully fire formed 22 K Hornet brass!!! No marking to indicate the conversion…
I guess my approach to these guns might be considered dangerous. But we are talking about rechambering (using a reamer to open up an existing chamber), not a conversion, for example from 30-06 to 300 Winchester Magnum. That conversion can be done badly, unnecessarily removing metal from behind the bottom recoil lug under the mistaken assumption that it was needed for the cartridge to feed and inadvertently creating an unsafe gun. Even a chamber cast won’t pick up that disaster in the making!!!
But, after all, the way you MADE 300 Weatherby, 375 Weatherby or 22 K Hornet brass was to fire form it from 300 H&H Magnum, 375 H&H Magnum, or 22 Hornet. Before purchasing, I would check that 300 Weatherby or 22 K Hornet brass would not chamber (I used to hunt with a Weatherby 300 Magnum so have lots of brass), but if not I’d just shoot the gun and see what the brass looked like. I think the only danger in this would be the situation Zeb described, where an incompetent gunsmith cut a sloppy chamber and didn’t use Go, No-Go gauges… But if the larger brass wouldn’t chamber I’ve just assumed that the chamber was factory original.
Maybe I’m just too much of a “risk taker”…
Lou
Lou, I think what you are suggesting the OP do is load and fire a 300 HOLLAND case and see if it fireforms into a Weatherby case – or a 300 Ardvaark or a 300 Mashburn Long, or a 300 Ackley Long, etc.
I think the OP proposed to fire a 300 WEATHERBY cartridge.
- Bill
WACA # 65205; life member, NRA; member, TGCA; member, TSRA; amateur preservationist
"I have seen wicked men and fools, a great many of both, and I believe they both get paid in the end, but the fools first." -- David Balfour, narrator and protagonist of the novel, Kidnapped, by Robert Louis Stevenson.
November 5, 2014
Offline
Hi Zeb-
What I was suggesting is that IF a 300 Weatherby case won’t come close to chambering, which it won’t in a 300 H&H Magnum chamber, then I would fire a 300 H&H cartridge in the chamber and see what the extracted case looks like when it comes out. Assuming my head was still attached… 
Everything else being equal, firing 300 H&H cartridge in a 300 Weatherby (or 300 Ackley Improved, etc.) chamber is no more of a problem than firing 22 Hornet in a 22K Hornet chamber. That’s how you made brass before you could buy it…
I’d worry much more about a standard action converted to short magnum, where some people did/do some dumb/dangerous things, than I would a long magnum 300 H&H versus 300 Weatherby.
Lou
WACA 9519; Studying Pre-64 Model 70 Winchesters
January 20, 2023
Offline
Lou, yes, I’m quite familiar with fire-forming standard cartridges in improved chambers and have done some of it myself. I once owned a Weatherby Mark V .240 Magnum and routinely ran a lubed 30/06 case up into the .240 sizing die, simultaneously necking it down to .244 and swaging the neatest belt you ever saw. Of course it lacked Roy’s radiused shoulder but that was cured by the first firing. Compared to Norma/Weatherby brass it was virtually free.
Nobody I know with a K-Hornet starts with anything but standard cases, either. But in all these instances, my friends and I were or are working with factory chambers or a chamber modified by a known, reputable gunsmith who had marked his work on the gun.
Street people say “Know your dealer.” I say “Know your gunsmith or know your chamber” — both are useful to keep out of trouble.
I draw the line at using standard cartridges in an unknown chamber. Why? Because a chamber modified by someone unwilling or too ignorant to mark the modification may or may not be a person fit to play with matches, much less a firearm. I might do it with a Mark V but not with a Mauser 98 derivative unless I could secure it and fire it with a lanyard.
Life is so much simpler with a chamber cast, a digital caliper, and the SAAMI specs. This will also give you useful information about the most advantageous bullet seating depth, maximum loaded neck diameter for adequate bullet release, and several other pieces of useful information you can’t get any other way.
“Every man for himself and God for us all” but I value my eyes.
- Bill
WACA # 65205; life member, NRA; member, TGCA; member, TSRA; amateur preservationist
"I have seen wicked men and fools, a great many of both, and I believe they both get paid in the end, but the fools first." -- David Balfour, narrator and protagonist of the novel, Kidnapped, by Robert Louis Stevenson.
1 Guest(s)
