No pistols? A 45ACP to the head from a short distance, or the 12 guage should do. I have never done it with rifle at distance. I hate having to put anything down.

Have done horses but never a cow. If it can be led it’s smartest to get it where you want it before you shoot it. They’re dang hard to move once down. Good luck.

Left ear notch to right eye. Right ear notch to left eye. .45 ACP on X, at point blank, and she's put down instantly.

I’ve used a 357 a few times. Quick and clean. Horses too.

A few years ago I had to do it for my FIL

I used a Ruger 10/22

Dead center from point blank

Luckily I found a few guys to take her

The meat locker won’t take them unless they can walk in

22 in the back of the head ball.

I'd not use the .22 on a 'pet'.

If she was kept just to keep a cow for the heck of it, or there is otherwise some kind of emotional attachment beyond what you might feel raising food, I would use a centerfire rifle. I know that seems like overkill but I had to put own a much smaller pet one time and used a .22 LR in the brain. It killed it but the death dance just tore me up inside. I tear up every time I think about it.

If it was raised for food that makes a huge difference.

At the meat lab we used a captive bolt with a 25 caliber blank.

Minimum I’d use would be a 9mm

Sometimes you need to use a tomahawk to make tomahawk steaks

I have a backhoe and was called to bury a donkey. The owner came out with a 44 Magnum to do the job. He shot the donkey in the center of his head, but must have hit him in an upward angle. The poor old donkey stumbled around until he fell into the hole. The owner shot him several times while he struggled in the hole. That was the biggest screw up and I felt sorry for the old Jack, but he needed to go. The owners friends gave him heck for his poor performance.

.22LR ear hole has worked on everything I’ve tried.

Shot a couple at the base of the skull aiming down into the spine....dropped both where they stood.

People overthink these things....

I shoot most of my trapped hogs with a single-shot bolt action.22 using shorts.....I’ve never hat to shoot one twice...

The dotted line on the pic on the right is exactly what I was talking about with a.22

That’s a big head for such a little brain... I know some folks like that...

I’ve watched my dad and grandpa put down a bunch with a 22. Right in the forehead.

I work with a bunch like gators.....15' lizard that can rip you apart in seconds with a huge mouth and a brain the size of a pea....Jes sauyin...

I had to use my 30.06 on one we had in the coral. It was was all I had at the time. It did the trick...

Seen grandpa put a few down with a 22, never had a problem.

A buddy did the same and missed his mark it wasn't pretty. He said if he ever has to do it again will use a bigger cal/cartridge for error.

I’m afraid that doesn’t count. They had been using a 38 Special but my first horse was important to them so I got nominated for the chore. All I had handy was a 454 Casull. No instructions since they didn’t want to be there. Turns out a bad shoot with a cannon is still very sad and ugly.

Im not saying a bigger gun will cure world hunger, but it can sure make a difference in a very minorly mis placed head shot on a 1500 pound animal when compared to a 22.

Only cow I’ve ever shot I did so with a .22 LR.

Hit her at 40 yards between the eyes and her butt hit the ground a second before her head did.

Didn’t make a move after that. I did put a .45 round behind her ear for insurance

We had to put down a calf (~200lbs) once because it had maggots crawling in/out of its rectum about 35 years ago. My dad chose a cheap semi-auto .22. He shot it 3 times in the head then the .22 jammed. That thing flopped around for a good 5 minutes before it died. Shot placement is key on a cow! The ear hole wasn't good enough.