Here are the facts:

1: I am shooting a Smith & Wesson Sport 2 with ~ 3-5 thousand rounds through it.
2: I have used a slide fire stock on this rifle for fun a few times, maybe 1000 rounds via slidefire. Barrel got really hot a few times for sure.
3: I took the slide fire stock off and was shooting 3MOA casually at 100 yards for months after. (Shitty steel case ammo)
4: Today out of the blue my sport 2 was key holing rounds. (Again steel ammo, I only shoot steel)

Is my barrel shot? or is this just a bad lot of shitty ammo coming to bite me in the ass?

Is there anyway to visually tell if the rifling on the barrel is worn down too much? I looked and it seemed fine to me.

Thanks guys.

PS. I know slide fire stocks are dumb. I am no longer am into that type of shenanigans.

Clean it really well, my rra started keyholing after about 20k rounds, every single one of which was 55 grain wolf with an occasional boiresnake ran through. Longest I went without any cleaning was over 7k I would have went longer but the extractor broke.

Steel cased ammo almost always uses copper washed steel bullets which cut barrel life in half. Not only are they the least accurate bullets available they raise hell on the barrel rifling.

Magazine dumps, bump firing and other yahoo style shooting activities cut barrel life no matter what ammo you're using. Heat is the enemy of barrel life. The hotter any metal gets, the softer it becomes. Magazine dumps are like sticking a blow torch in your chamber with 55,000 to 62,000 psi. pressure waives being introduced with each shot fired. The barrel doesn't have time to cool between shoots, most gun powders create temperatures over 4000 degrees F. when they ignite in your chamber.

Clean your rifle thoroughly. Lots of passes with a brush the same way the bullet travels down the barrel. Remove the bronze brush after it exits the muzzle so as not to drag it through the crown. I would make at least ten passes. Follow with wet patches of solvent. After you are convince the barrel is as clean as you can get it, try some USA manufactured ammo to see if it will shoot it. If it won't you're SOL.  

I won't shoot steel case simply because I'm an accuracy nut. But if it did shoot well I would still avoid it simply because of what it does to barrel life.

Thanks for the reply!

Clean the shit out of it.

Shoot some USA brass.

If keyholes im SOL. Got it!