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Bison Hunting Caliber

hearteater

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I will be going on a bison hunt in Wyoming this year. The only rifle I currently own is a 7mm rem mag. Shot placement arguments aside, you guys think this is enough gun for a bison?
 
With the right bullets (160gr+ premiums) I'd have no trouble going after bison with a 7 Rem Mag. I'd load a 175gr Partition and get after it.

I shot a cow bison with a 210gr Partition out of a 338 Win Mag under a pretty tame situation. They are big, but I have no doubt your 7Mag wouldn't have done just as well.

If you can find it, pick up a copy of Warren Page's "One Man's Wilderness". He travelled all over the world and used a 7mm with Nosler for a lot of big game to include brown bears in AK.
 
Buffalo are strange critters, and can be very hard to take down. I shot a bull myself and I have taken 5 other friends hunting for Buffalo up on the Crow reservation in Montana. Here is my quick feedback and theory. Bison have huge lungs, and therefore they can withstand several gun shot wounds before they die. Bison have a single sack (membrane) around both lungs, so once you puncture that bag eventually both their lungs will collapse. The challenge is getting enough of a pressure differential inside the chest cavity to collapse there lungs (a good entry or exit wound is what you need). Because of this unique challenge, archery equipment can actually be very effective, an arrow that penetrates the lungs and then protrudes from the animals body will quickly allow air into the chest cavity and both lungs will collapse. The flip side to this is, modern day high powered rifles sometimes can be challenging with bision, because the entry wound is very clean and you may not get an exit wound (The bison's fat can seal up an entry wound). Take this info for what it's worth, some of this info is first hand experience and part of it is online research as I prepared for archery hunting a bison.

My experience -
Using a .300 WSM with 180gr bullets - Shot a large mature bull at 300 yds. first shot was slightly back, but still hit the lungs. the bull ran off over two miles. I found the bull bedded and snuck up to around 40 yds. The bull stood up and began to walk away. It took 4-5 more rounds in the lungs before the animal tipped over. My last shot finally broke his shoulder and put him down. They are incredibly tough!!!

1st buddy - Shot a young bull at about 150 yds with a 30-06. He shot the bull right in the middle of his neck, the bull reared up in the air and fell over dead. It was a "bad" shot, however it was very effective.
2nd buddy - Using my .300 wsm - Shot a cow at about 200 yds through the lungs. The cow laid down and died fairly quickly. I did not get to inspect the bision, but I suspect it had a good exit wound.
3rd buddy - Shot a bull at 200-300 yds. He hit it 3 times through the lungs. The bull crashed down through some tree's and laid down. He had to shoot it twice in the head with a 45-70 before it died at about 10 feet.
4th buddy - Very similar story to my bull - Shot a bull at about 300 yds. Had to chase the bull down and later kill it in a short range gun fight.
5th buddy - Shot at a cow that was quartering too him at 150yds. The shot hit the bisons neck, and same response. The bison reared up in the air and fell over dead.

The Crow guides suggest that you shoot bison in the soft spot of their skull. I was never in a range where I felt comfortable taking that kind of shot, however you can see our results above. Also talking with the guides about our experience, they said that they have seen people shoot bison with just about every caliber, and some animals die very quickly and others run away (Again they claim the head shot is best). They don't seem to see a large correlation between the caliber used.

All I can say is use the largest grain bullet you can get, and hope for massive entry and exit wounds.
 
I couldn't find that anywhere...All I could find is the regs say minimum of 150 grain bullet.

To the OP...7mm should be good but I'd agree with 1_pointer and say a 175 grain bullet would be my suggestion

The boy had a Bison tag 3 or 4 years ago and the CD the FWP gave him to watch said the state minimum was 30 caliber
 
Thanks for the responses guys. I usually shoot 160 grain nosler partitions. I've killed many deer, black bear and a moose with it. I don't hand load so there aren't many 175 grain options.
 
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Thanks for the responses guys. I usually shoot 160 grain nosler partitions. I've killed many deer, black bear and a moose with it. I don't hand load so there aren't many 175 grain options.

It's tough to argue against a 160grain partition. Since you don't reload and it there are only a handful of factory 175grain loads I'd probably use your current load.
 
I have never shot a bison, BUT I do know how well the 160 Partition works. I have used 175-grainers, also, and I do not believe that you give up anything with 160s. You should be just fine with that load. Shoot til they fall!
 
I've killed one with an arrow. Ran about 70 yards and fell over dead. Killed another one with a .338. Took three rounds but she was dead after the first, just didn't know it yet.

We were involved with that goat roping a few years ago that got the guide gored and hospitalized a few weeks later. We topped a hill and ended up thirty yards from a large bull just as a girl thumped him with a couple rounds of .338. The bull saw us and thought we were the ones causing him the pain. It was an interesting few moments bailing for a tree to hide behind. A guide and a hunter came up on that wounded bull later in the season. He ended up in the hospital.

Know another guy that ended his season in the hospital as well. They can be tough, mean critters.

Now that the scary stories are over, I've watched probably a couple dozen bison killed very easy with everything from .270-.338. You will fine with Partitions. Make a good clean shot.
 
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https://wgfd.wyo.gov/WGFD/media/content/PDF/Hunting/Bison/BISON_KNOWDIFFERENCE.pdf

I would not hesitate for a moment to use 7mm, provided it is legal and you shoot it well.

A common mistake many folks make with bison is aiming too high, and also too far back. This Wyoming G&F document shows a good view of the vitals. Note how low the hear is. Aim for that and you'll be fine.
I can very well see that last bit about too many folks shooting too high and back being an issue. It's quite apparent how differently they are built once you have the hide off and have them cut in half. I was in a very controlled environment so I shot just behind the shoulder. If I was in a more normal public ground setting I'd probably shoot through the shoulder and still low as there's a lot of plumbing right there.

The 15gr difference between a 160 vs 175 is nothing I'd worry about. It's less than 1/2 a .22lr bullet...
 
I think you will be just fine with the 160 gr. Partition in your 7mm. It's a great bullet and the 7mm Remington is not too bad of a cartridge! Best of luck. Make a good shot and you will be just fine. Make a poor shot with anything large or small and it might get interesting. We expect many photo's later on! What good is this forum without pictures!!!
 

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