12 ga vs 20 for deer?

just stick with your 20 gauge, you're used to it and as you said, it works.

The 12 gauge is more powerful than the 20. It will do more damage. It does have more recoil, though. I've fired both from a single shot platform and the 12 gauge can hurt if not handled properly. But in a pump or an auto-loader the recoil isn't as bad. If the 20 works for you, stick with it. I've personally killed a deer with an HR single shot chambered in 20 gauge. I used a rifled slug and it had no problems giving the deer an ethical death.

OOOoooo, a simple short answer. 1200 feet per second is 1200 fps no matter what it came out of. The difference is only the weight or the slug. As far as diameter, I consider that no concern, you are throwing a much larger rock then most any Deer legal handgun*, and at equal velocity.

* many states require a "straight wall" handgun cartridge.

12 ga recoil will be higher than 20 ga. By a good bit, IMO.

For slugs and buckshot, both are PLENTY of power for deer... at reasonable ranges.

20 ga buckshot typically comes in #1-#4 size, which is smaller in diameter and weight compared to the 0-0000 buckshot of 12-ga. Heavier shot = more momentum for the same velocity, and that means either deeper penetration or the same penetration but a larger wound cavity. Or it means the same wounds at longer distance with larger/heavier shot.

However, #1-4 buckshot is not small... and you get a lot (like 20 #3 shot) in a shell... which means lots of killing power for either... What you really gain with 12 ga is better penetration at near its max range.

But with a slug, you negate that anyways... since slugs have significantly longer range and killing power at range.

Here's a size comparison of shot:

12 gauge, no question. You want to be sure the job gets done.

move on up to a "big boy" gauge....girls shoot 20's......

Many many hunters I know in shotgun only states have switched to the 20 gauge. Now most of them are using rifled barrels with sabots. Any 20 gauge slug should be more than enough for deer and the 12 gauge
s recoil is severe with slugs.

A 12 gauge will recoil more. But if you have a gun that will do the job, your chances are based on your skills as a hunter and marksman. Your 20 gauge is more than adequate for hunting deer, no reason to switch to a 12 gauge - you would only end up with 2 tools that do the same job.