I suspect the father-in-law read something about the 257 being Roy Weatherby's favorite cartridge and that he took it to Africa and killed a cape buffalo with one shot. I wouldn't call it ideal but I wouldn't hesitate to use it with a super premium bullet. Remember we are talking about Maine moose not the monsters like in BC or Alaska.

 

I've shot three Moose. Would I hunt them with a .257 Weatherby? Yes, with 120 Partitions. Would it be my first choice? No.
After killing three if I ever go for number four I will use a .30-06 with 200 grain bullets. You and your friend were much better armed.

 

To expound on my point I've shot them with 150, 170, 220, and 350 grain bullets. I've seen them shot with 150 (7mm) and 180 grain bullets. My experience FWIW leads me to desire at least a 200 grain bullet on moose.

 

<span style="font-style: italic">Capable?</span> Yes.

Ideal? No.

I'm a firm believe that a lot of American hunters tend to go overboard with their cartridge selection for a given game animal. For instance, nobody can convince me that you need anything as large as a .30-06 to cleanly drop a whitetail. It will work just fine, but it certainly isn't a minimum by any stretch. However, I'm also a firm believer that a lot of American hunters put WAY too much stock in bullet velocity (<span style="font-style: italic">see also, Roy Weatherby</span>) and expansion as a killing mechanism over bullet weight when the time for hunting a larger animal comes along.

The old buffalo hunters were lobbing huge, cast lead bullets at speeds you could measure with a sun dial, sometimes killing multiple animals with one shot. Conversely, if you send a small, lightly constructed bullet at warp speed, you can expect a lot of meat damage in a good situation, and a superficial blow-up/wounded animal in a bad one. Even a .30-06 with an improper bullet choice can go wrong. I personally watched a shoulder-shot cow elk that a buddy hit with a 165 gr. Hornady SST take off up a mountain like it had 5 good legs when the bullet failed to penetrate and drop it. That's not a bad bullet, it was just a bad choice <span style="font-style: italic">for that animal</span>. It's simply too lightly constructed for the possibility of hitting larger elk bones and the results showed it.

Yes, you can probably count on a .257 Wby driving a well-constructed bullet to do the deed, but as triggercreep stated, a 30-06 with a 200 grain bullet would be a much better choice.

I think you were significantly better equipped and more than adequately armed with the .35 Whelen and .300 Win Mag choices than a guy using a .257 Wby mag.

 

I'm on board with the majority thus far...

CAN that 257 Roy work on a moose? Sure.

Would I personally choose to use it? Nope. Not even on a dare. It could work, but if I'm putting my time off, my money, and my effort on the line, I want something with a little more margin built into it in my hands when my moment comes.

One of the reasons I tend to select more substantial cartridges than needed for deer is that I am usually pretty confident that I will get an opportunity at whatever it is I'm hunting. At some point. I may well only get one chance, and it may not be an ideal shot angle or distance or whatever. So I want something that's up to the task when things aren't perfect.

Now, don't take that to mean "I'll take Texas Heart Shots at 700 yards because I have a [cartridge designation here]."

What that means is when I see my buck I want to shoot and he's at 200 yards quartering at me, I want a round that I feel very confident will bust through the shoulder and get to the lungs and out the far side.

And what gives me comfort of mind that such will happen can and will differ from what will make others feel comfortable.

For a moose hunt, I'd have been quite pleased with a 35 Whelen in my hands. I think that's an excellent choice, although I've never hunted moose. Mooses? Meese?

Anyway....I also agree better choices for that application exist.

 

Keep in mind it used to be a common practice among the native tribes in Canada to shoot a Moose through the lungs with a .22 rimfire and follow it around until it collapsed. So you can kill a Moose with any cartridge. But you can't dump a moose with any cartridge and the place where he is standing may be a lot more convenient than the place he will run to. Take enough gun to drop them in short order because it really bites when they make it to thick brush or water.

 

FYI The 6.5 x 55 is the most popular moose cartridge in Sweden. Similar but less powerful than the Wby.

 

FYI The 6.5 x 55 is the most popular moose cartridge in Sweden. Similar but less powerful than the Wby.

I used to talk to a Swede about Moose hunting on social media. He told me the .30-06 surpassed the 6.5 Swede long ago. He liked a .300 RUM and a .450 Marlin.

 

A 140 from a 264 is a significant upgrade from a 120 in a 257.

The Weatherby is able to kill the moose, I've no doubt.

I'd want a bigger bullet, personally.

 

Have a 257 and yes it will kill a moose but I would not use one being that I have other choices. It's not so much the bullet diameter but I would prefer a heavier bullet which means bigger caliber, now that 35 whelen I would consider ideal!

 

A great well constructed bullet like a partition or x-bullet at 3500 fps will take out any moose like lightening, these .257 can easily push them that fast if not faster...there is only a slight difference between. .257 vs .264, .007 of an inch, I don't think any animal would notice the difference..just use a great bullet, but it's always the case !

 

It's not just the diameter difference, it's the weight. +20gr of mass is about a 17% increase (120 to 140). That's significant.

The fact that it doesn't get appreciably wider but DOES get heavier means it gets longer.....that's precisely why the 264-bores are known for penetration and great BC's. If someone made a 140 for a 257, it'd be essentially identical to the 264 bullet, but they don't make such a thing.

Most 257 rounds are meant to run 100gr bullets and lighter. The 110's and 120's are the heavy end for the 257.

One can get 160's for the 264 if they look hard enough. Those are monsters.

For something big and heavy like a moose, my personal pick goes for bullet mass. More mass helps with penetration. A great bullet like a Partition in a quarter bore isn't a bad idea. A Partition in a 338 or 358 bore is an even better idea, I think.

 

I think true Moose cartridges start at .30 caliber but that's my personal opinion and doesn't change how well or poorly a 7mm Mag works on them. And a 7 mag is my rock bottom Moose round. I've taken one along Moose hunting but never shot one with it.

 

I own a Mark V 257 Weatherby. Would it work on a moose? Sure it would with a stout 115-120gr. premium bullet. Would it be my first choice as ideal for the job? No way!! The 257 Mag. is IMO the best of the lot for an open country medium game cartridge but far from ideal for moose. For moose I would choose my Mark V Stainless in 340 Weatherby Magnum. Now that's a moose cartridge!!

 

FYI The 6.5 x 55 is the most popular moose cartridge in Sweden. Similar but less powerful than the Wby.

I used to talk to a Swede about Moose hunting on social media. He told me the .30-06 surpassed the 6.5 Swede long ago. He liked a .300 RUM and a .450 Marlin.

I didnt know that. Everything I read talks about the 6.5 Swede.

 

I've watched 18 moose die. None were shot with anything less than .30 cal belted magnums, other than one killed with 7mm mag. I've put 4 shots into the chest of a bull with .300 win mag and they still held their ground for moment. I personally wouldn't hunt them with anything lighter than my .300 win mag or .300 WSM. I knew guides in Newfoundland that hunted them and caribou with .243s ; I wouldn't do it.

 

I've heard it a lot too and believed it. The Swede explained to me that it's like saying "Canadians mostly use the .303 British" or "Americans prefer the .30-30". It was all indeed true several generations ago but now it's outdated information.

 

I would not use anything smaller than a 7mm Mag. In my opinion, is a little light too. I took a 7mm Mag as a 2nd rifle on my recent Newfie moose hunt. I only took it because I just put a new scope on my 338 WM and wasn't confident with it. Anyway, I killed the moose with a 300 Win Mag at 125 yards.. A 180 grain Nosler Partition went through it's left shoulder (high), through it's spine, and did not exit the moose. I recovered the bullet inside the hide. Yes, it was less than an ideal shot, but ideal shots (a clear broad side shot, animal not moving) doesn't always happen.

To answer the OP, the 257 ROY is too light IMO.

 

I took a 7mm Rem mag as a backup on my 2004 Moose hunt. I used 175 grain Federals. My primary gun was a .450 Marlin and that's what I ended up using on a 9 1/2 yo bull. I would've been comfortable with the 7 mag because I had the right bullet. I wouldn't stay home either if all I had was a .270. But you have to pick your shots with stuff under .30.

 

Sure a 257 with Barnes x or partitions will do fine.as long as u get good shots into the boiler room.I would use it if I dident have options but for me 338 Winchester.210 grains.that way I know if I need to take a shot from most angles I will get more then enough penetration.

 

I took a 7mm Rem mag as a backup on my 2004 Moose hunt. I used 175 grain Federals. My primary gun was a .450 Marlin and that's what I ended up using on a 9 1/2 yo bull. I would've been comfortable with the 7 mag because I had the right bullet. I wouldn't stay home either if all I had was a .270. But you have to pick your shots with stuff under .30.

I agree about picking shots. My preference is/was to have some a little heavier because I usually am not lucky enough to get the "perfect" shot.

 

Sure a 257 with Barnes x or partitions will do fine.as long as u get good shots into the boiler room.I would use it if I dident have options but for me 338 Winchester.210 grains.that way I know if I need to take a shot from most angles I will get more then enough penetration.

Shot placement is definitely key!

 

I took a 7mm Rem mag as a backup on my 2004 Moose hunt. I used 175 grain Federals. My primary gun was a .450 Marlin and that's what I ended up using on a 9 1/2 yo bull. I would've been comfortable with the 7 mag because I had the right bullet. I wouldn't stay home either if all I had was a .270. But you have to pick your shots with stuff under .30.

Uneeded comment

 

Personally I wouldnt say the 257wby would be the perfect moose round. But; I wouldnt hesitate to use it if that was all I had.

Good luck, Tony