I am taking a carbine class that will require about 1500 rounds in 3 days,  I am having trouble getting reloading components, but I can get 6# of 2520.  I plan on loading 55gr FMJ hornadys, and have Federal standard small rifle primers.  Does this sound like a workable load?  I would really like some H335, but I don't think I can get enough.  Is 2520 clean enough to keep a gun running for 500+ rounds per day?

Accurate's website shows data for 2520 starting with 60 grn soft points up to 80 grainers.  I've used it with 77 SMK.  It's ball so it meters well, doesn't seem any dirtier than others but I haven't shot 500 rnds per day of it as you plan on doing.

AA 2520 is kind of slow for 55 grn bullets...

Powder Valley still has AA 2230 that will work well for that bullet...

Have fun at your class...

I have loaded AA2520 with 52gr and it is very accurate. More muzzle flash than faster powders though.