I use a shotgun in the bush for Pigsall though I am thinking of trying a Bow,My deer rifle a .222 is not up to the job for pigs what is a good calibre for a pig rifle.

I pretty much use my bows these days 100%...but when I do use a gun, I use my .270, never had one walk away.

Itis up to knocking pigs dead in their tracks providingthe right bullet is used and providingyou pick your shots carefully. I often hunt a huge piece of property that is restricted to rimfire rifles.i use a22 magnum when hunting there anditdoes a good job on hogs. Have killed a fewhogs with the .22 Hornet and quite a few with the .223.There is a man on this site who routinely kills big hogs with his .22 Hornet.

Most ofmy hogs are killed with a .50 muzzleloader.

put that .222 anywhere within 3" of the ear and even the biggest of pigs will drop on the spot.
and I am that guy who kills them regularly with a .22 hornet.

These were all taken with Traditional Archery.
A rifle is too easy, but I do use a side arm, when we take Kids to hog hunt.

Nice group of hogs...

I primarily use my T/C Encore Endeavor muzzleloader when I hunt hog and deer. But I do have a Remington 700 .30-06 I can use. But I just love the muzzleloader too much and the challenge of needing to make that one shot count. I also have a shotgun but I never use it for deer or hog.

From a practical (cost/benefit) standpoint, I like a .30 caliber rifle. My own rifle is an old WWII era .303 Enfield that's been 'sporterized' with a modern stock and a scope. A 30-06 or a .308 work well, and I think an SKS would also be a good option if you're budget minded. Of course, as others have pointed out, if you hit them in the brain with just about anything they're pretty much yours. I would think a .222 would be okay, the key is, whatever you're shooting, to use soft point ammo. FMJ just doesn't do as good a job and I'd consider it inhumane. Your odds of wounding and not finding are greater with the FMJ ammo.

Not all military FMJ bullets are created equal.

I have killed a lot of hogs with the US military M193 5.56mm round. Nearly all of those hogs were bang flops: Never lost a hog that was hit with that bullet. When fired from a 20" barrel from a distance of up to 150 yards that bullet penetrates 4.5-6" in hog flesh, yaws90 degrees and fragments.

A good friend of mine still carries over two dozen fragments of a 7.62x39 bullet that he was hit with in Viet Nam in 1968.

http://www.rayguncharlie.net/sr/basics/pmrb.html

http://www.uthr.org/SpecialReports/Military_rifle_bullet_wound_patterns.htm

A well placed shot from a .22 on up will drop any hog. I use a Ruger .22, .22 mag, Bow, .243 .45 long colt. and a .44 mag. The .44 is my choice.