Any small or medium ball
Mine shoots inferno well also venom & anarchy
low price ($15 on e-bay)
much better than stock
nickle plated exterior
This a much better than stock for the a5. Shoots a much tighter group from 50 foot on out to 150 foot. Shoots clean usualy in 3 to 4 shots (don't have that problem with the a5 often, no breach brakes in over 7 cases) This is a good inexpensive upgrade. I have a 12 and a 10 that I bought on ebay for less than $15 each new. The only barrel breaks I had were with proball in very cold weather ... about 1 per hopper. I attribute this to the balls getting too cold and brittle.
Some barrels get bad reviews when the problem is the gun and it's owner. Some guns (spyders, BE & cheap BB knock-offs) have such poor velocity consistancy that the gun blows balls and chops know matter what barrel they use. I can't the number of times players come up to me when refing with paint running out the end of the barrel when it wasn't even screwed in all the way.
Good barrel for $35 excellent barrel for the price when you can get it for $15!