Using BB's in a pellet rifle (rifled bore)?

[His lordship.]

I bought a Daisy 901 multi-pump air rifle and it says you can shoot BB's and pellets in it, it does have a rifled bore.  I have read that accuracy suffers when using the steel BBs.  I mostly will use pellets but am wondering if the steel BB's will harm the bore, or are they more like a .69 caliber lead ball in a flintlock musket in that the bore is .72 caliber and the projectile will bounce around as it goes down the barrel?
 
I have not shot a BB gun since I was a kid, have only used pellet guns the last 30 years.  I remember the Crosman BB long guns we shot as being accurate at close range. 

[keith44]

Wow, I can tell you the theories of how the looser fitted BB would (should) be less accurate, but you already know that from reading.  A pellet only rifle can be damaged by shooting steel BB's, and it would cause the pellets to also be inaccurate.  A rifle designed to shoot both (in my experience) has an oversized bore, and does not develop enough power to cause damage to the power system.  Being a pump up the system is pretty well self protecting.  So that leaves accuracy.  Top accuracy will not be had with this design, but my old Crossman 760 was accurate enough and powerful enough to hunt squirrels and rabbits out to 25 yards.