RE: .270 Which bullet?
If you really think a longer shot might be possible give the SST' s a try. If they don' t shoot as well as the cheaper Hi-Shoks you have lost very little other than a few bucks and some time, (if you call practice a waste of time or money?!?). I have never used the SST' s but I have been seriously thinking of trying them myself.
Let us know how it turns out! Good luck.