I always assumed it was amount of powder. My 257 wbymag barely kicks at all. I thought it would be a big kicker because of the amount of powder(energy) coming out of that little hole. On the other hand my 7mm-08 kicks harder than i expected. So what actually determines the recoil? Is what i have noticed all mixed up? Is the weatherby just a better rifle thereby kicking less? Is it more about the powder or size of lead? Can you just look at a bullet and safely assume what to expect to feel?

Weight of the rifle, weight of the projectile, amount and type of powder used

Rifle weight, bullet weight, and velocity pretty good calculator below
http://www.shooterscalculator.com/recoil-calculator.php

That’s a good start but felt recoil changes SIGNIFICANTLY with stock design. My go to rifle is a lightweight 7 Mag with a McMillian stock. It’s a hot load (150g at 3250) but felt recoil on that particular setup is very light. On the flip side I’ve got a 6mm Remington Cooper Model 52 with a claro walnut stock. It’s felt recoil is double the 7 mag.

Stock design is the number one factor in how recoil actually feels. It can make big cartridges tolerable or medium cartridges brutal.

^^^^^this. You have straight up energy that can be calculated based on the cartridge. Then you have how the energy is transmitted to your shoulder, face and sometimes eyebrow.

How that energy is transmitted depends on quite a few factors, .....weight of the rig, design of the stock, and how it fits the shooter.

here is another link I find useful https://www.chuckhawks.com/recoil_table.htm

It would appear in those charts the recoil is directly related to size of lead.

I think all the factors play a part but in my opinion rifle weight changes the felt recoil the most and stock design a close 2nd. For example I have 2 tikka 308s. one is a factory lightweight 20 inch barrel. The other is a 22inch barrel in a Boyds stock with a heavier scope and steel rings.
I don't know the exact difference in weight but with the same ammo there is a big difference in felt recoil between the 2

Different stocks absorb energy differently. If you have no recoil pad, you’re going to get more of a sharp recoil than if you have a large recoil pad, which turns more into a push then a sharp jolt against your shoulder. The material of the stock (wood vs plastic, etc) can also have influence.

Stock design and position while shooting prones the worst cause your body is straight. A 125 grain .357 in a 23oz revolver is way worse than a 5.5 lb Marlin lever gun. Recoil "speed" is the killer a 5.5 lb Kifaru .338 felt like Tyson punched my shoulder and a .470 Nitro Boss felt like a gentle shove.

E = MC squared.

The target.

I know thats right. A little bit of adrenaline is the best recoil reduction device

. Most guns kick at the range, very few are felt when firing on game.

All I can tell you is the Winchester Model 70 Extreme Weather SS in .308 is a fine shooting rifle

I have a very lightweight savage 110 in 7 mag. In a hogue stock. Hand load 150 gr. Pretty hot and it kicks like a 22 mag... But I have a weatherby 7 mag shooting 160 gr. In a factory stock and it kicks like a 7 mag. Not bad, but not a noticeable difference.

Shoulder angle can play a part as well. The sharper the angle, the more perceived recoil. The 7-08 in the original post is a prime example.

The 7-08 is a savage axis, the 257 is a weatherby. I figure that is the biggest difference in my case. The savage shoots good but it kicks hard and is very loud.

A 3 1/2" 12g 870 using extended range with 2oz of #5's will kick more than .338 win mag