Several years back, the NRA did comparative tests with multiple firearms. The 1-9 twist won the accuracy test with all except the long, heavy bullets like the 77 gr SMK. The twist won't stabilize that load (or the 75 gr Hornaday plastic tipped bullet).

Yes, the bullet has to be both long & heavy. I've loaded some 55 gr Barnes RRLP bullets that are 55 gr and over 1 inch long. They stabilize just fine at 2920 f/s from a 1-9 16 inch barrel.

I've got a 1-10 barrel that will shoot 69 gr SMKs very well, 75 gr Hornaday HPBT keyhole at very close range. On the other hand, the 1-9 shoots the Hornaday bullet extremely well.

I can buy the theory that the faster twist leads to faster barrel wear, I'm just not sure most folks will ever fire enough ammo fast enough to really see a difference. If you're into multi mag dumps on a regular basis, maybe.

So, if you have some need-real or perceived- to shoot 77 gr SMKs (forget the military coding for the load) or similar loads, get the 1-7 or 1-8. Or, if you just gotta be mil-spec.