I had 3 brands CCI federal Hornady they were sealed plastic boxes they have lived in a closed storage room for a few years, but they are over 10 yrs old. all my other rifle, pistol, 22lr, shotgun and all have shot fine.
OK, so your other guns have shot fine. There is still a distinct possibility that, for some reason, your .17HMR ammo got contaminated. You stated that you had a squib load. What made you think it was a squib? Did the round sound normal when it went off, or did it sound totally different (muted, soft or phhhht)?
Once you get the bullet removed from the barrel, I would suggest you obtain a brand new box of ammo, load up one round and shoot it. I would be surprised if it is another "squib". If, by chance, that one round ends up stuck in the barrel yet again, I would strongly suggest you completely dismantle the gun (for parts) and throw what's left in the deepest lake in your neighborhood.