Hornady specifies using a 1 in 8 minimum. I've used the 73's in 1 in 9 twist rifles, but prefer to use them in my 1 in 8 and 1 in 7 rifles. Accuracy was good in the 1 in 9, but that was my rifle. Yours may be different. I was also running a 20" barrel, so that may make a difference. A bullet stability twist rate calculator will tell you that stability will be marginal at best. Generally when I'm shooting a 1 in 9 twist rifle, I stick to bullets that are 69gr or less. I would not use the 75 or 80 eld in that rifle either. The heaviest I've tried in a 1 in 9 is the 77 TMK. Contrary to popular belief, that bullet shot well at 100, but really fu cked at 400. Of course YMMV..
