DO NOT use any Canadian Tire or Walmart BBs in your gun. They are meant for the crappy clear plastic guns that are sold there.
You have a decent gun that you don't want to ruin with shitty BBs.
A bag of 2000 BBs will easily cost you $15 dollars. That's considerably cheaper than what you'd pay in repairs if a walmart or crappy tire BB shatters inside your gun and lodges itself somewhere.
Look at online stores. You can even buy them in bulk for a cheaper price
H&K G36c (KWA) / Glock 18c (TM) / Kimber LAPD SWAT Custom (TM) / Mossberg M500 (ACM)