I've used the SST in several cartridges including the .30-06 and find them to be an excellent bullet for deer. For elk sized targets I'd prefer a bonded core bullet such as an accubond or interbond.

I consider the SST to be a soft point even though they are a polymer tipped bullet identical to the ballistic tip.

A 140 SST out of the .270 Winchester is very much a deadly item for a deer.