Jeff- I gotta believe that they're Interlocks, call the good people at Hornady and find out for sure is what I'd do.

One thing I know for sure about those that dog Sierra's. Like most things in life those with the least amount of experience with something tend to say the worst things. And or make things tons load tougher than it ever need be.

I've seen more elk taken with 130 Sierra BT's out a 270 than most people will ever kill in a life time of hunting elk. Never had a problemo and don't spect to either.

Seriously if you want to use those 170's go out and fill up an ark with them. They'll no doubt do the job if you do yours.

Dober

"True respect starts with the way you treat others, and it is earned over a lifetime of demonstrating kindness, honor and dignity"....Tony Dungy