You say you draw 72 lbs , what draw length? in other words how much Kinetic Engery do have leaving the bow?

Rules of thumb that I follow. My set produces 58 ft of KE at the bow. I can use a 1.5 inch cut if I limit myself to 20 yards, any farhter than that I may or may not get a pass through that is the largest cut I will use. the 1 3/4 inch and larger needs KE into the 70 + ft lb range to push them the way they are supposed to be pushed. keep in mind the farther the target the less KE there is when the arrow gets there.

If I want to shoot to 30 yards I go to a 1 1/4 inch size, I feel more confident about the pass through thing. So I use a 1/1/4 inch most all of the time. I find that size large enough for any deer. and it works really well inside 20 yards. that's three blades, now if I'm useing 2 blades I will go with the syniper out to 30. and a gator if I am inside 20 yards.

If I expect to shoot out past 30 yards I'll go with a fixed broadhead. I used magnus stingers last year. I found some 3 blade muzzy's in the box the other day so I suppose I'll use them this year if I run low on the stingers..

So if your going out west for a lope I imagine it will be a 30 plus yard shot more than likely so I would have 1 1/4 inch mechanical and fixed ready to go.

some states out there don't allow mechanicals at least that is what I've heard on these boards.

A couple of years ago my rig produced 54 ft lbs and I hit a deer in the heart at 27 yards with a 1 1/4 inch size 3 blademechanical. The heart was meaty enough to stop the arrow, did not get a pass through, deer went down quick but no pass through. Also if you try to pass through from the back rib out the front with a larger mechanical at 35 yard range you might not get a pass through.
You have to learn there are some limitations with a mechanical and decide if your hunting style can work within the limitations of the device.

Biggest mistake I hear when you get the shooters to fess up is that they tried to shoot a larger cut at a far distance with too little Kinetic energy to begin with. hence no pass through and another mechanical broadhead failure report that isn't really a mechanical failure at all.

Good luck out there, I would make sure my bow would shoot a magnus stinger 4 blade out to 50 yards at least if I were going out west. then hope I could get a shot between 20 and 35 yards..

good luck to ya.