You should be fine with the load you are asking about. I'd second Lee's comment on people using bullets outside of what they are designed for. A lot of tests that I've seen show that the regular 250 SST is a fairly "soft" bullet that works well when pushed at 1800 - 2000 fps max. At speeds above that - that's where it seems to have problems sometimes, and it would be better to used the bonded version or the 300 grainer.

Your 2 pellet load will put you around 1800 fps, which should work just fine with the SST. If you still have worries, I'd suggest a 250 or 300 grain XTP- they are cheap, easy to find and have a good track record.