I'm trying to get some advice on 22 cal. ammo. I have a totally restored Winchester model 74, 22 cal. LR semi-auto Rifle.
Looking for the most powerful 22 cal ammo that I can use in my 74.

Heard about Hornoday's 22 cal shell tapered to a .17 bullet. More power.
Same size as 22 cal LR shell.

any advice?

RHW

The 17 hmr is a 22 mag cartridge "necked down". It is a very hot/fast round, and it is very accurate. You have to have a 17 hmr rifle to shoot it. Anyways back to the ammo question. The best ammo these days is the one you can find to buy. It is very scarce here. Try to find ammo that DOES NOT have the wax coating. CCI loads are notorious for having a wax covered bullet. You can tell by scratching the bullet with your finger nail. The wax will build up in your action, gum it up, cause jamming, and is very hard to get out of the action. The best round is the one that your rifle likes. Just go to a few friends and get a few rounds of each brand you can find and shoot some groups. The round that has the best group and lacks the wax coating is the best one for you.

There is an entire universe of 22lr ammunition out there. From magnums to little shot shells to sub-sonics that sound like a pellet gun.

The question is what do you mean by "best?" Most accurate? Most reliable? Highest fps? Highest energy on impact? Heaviest?

Unless you're at a match or competition just about any $20 brick will fire when the trigger is pulled and hit it's target.

You can kill small game like rabbits and squirrels just fine with sub-sonics. I always keep a bunch of sub-sonics around for shooting off just about anywhere. People just think it's a BB gun.

Dont put any 17HMR's in a gun not specifically marked for them and don't put any 22lr magnums in a gun not specifically marked for them. And those 22 shotshells will mess up your rifling so dont mess with those if you have a nice match barrel or anything.

here's my thoughts...
Some folks will say the soft lead, (No brass Just a dark gray bullet), are more accurate and have more velocity over the Jacketed ones... Maybe true for all I know??? What do know is you'll need to clean the barrel a lot more often shooting lead rounds...