Well - a number of you have really helped me find bullets/sabots that I can load in my CVA/BPI Beartooth, so here's the results of my afternoon at the range Saturday.
I started with ballets at the 25 yd range. They pretty much grouped in a jagged hole with 1 - 50 gr Pyro pellet. Then I fired a 3-shot group of .451x260 gr Speer JHP'sin Crush Ribs and 2 pellets, getting a group that was a little over 1" c-c. I then adjusted the scope for a 1" high group at that distance. I tried some 270 gr Sabertooths, but couldn't get them to group well at all (at 25 yds) - kind of surprised me - they must fit too loosely to stabilize well. THAT surprised me too - that ANYTHING would ever be too LOOSE in my barrel!
Moving over to the 100 yd range (nothing in-between), the 260 Speers were landing 4" high, but in line with the bullseye. I then changed the scope to print approx. 1" high at 100 yds.
I also fired some .451x230 gr XTP's and .452x250 gr XTP's in both Crush Ribs and HPH-24 sabots. They all grouped well, with slightly different POI.
The .452's loadednoticably harder, so I probably won't use them again.

My groups at 100 yds were nothing to brag about, but I had a 10-15 mph gusty crosswind from a 45 degree angle - not a good recipe for tight groups.
One thing I really noticed - my groups are real good up & down, but tend to spread side to side. I'm pretty sure some of that is me, but how much of that can I expect from a crosswind like I had?
I have just about used up my box of Pyro pellets, so I just bought a pound of 777 in ffg. As soon as I receive my Barnes bullets (T MZ's still on backorder), I'll go out again, this time starting with 80 gr 777 and see if I can get some better groups.
Thanks to all for your help - I think I'm on the road to finding some real decent loads for my gun.

IM jaybe

a cross wind at 100 yards, especially with strong gusts can move you a lot further side to side then you think. It sounds like you have some good groups worked up, and they will only get better... nice shooting

Jaybe, according to my calculater a 15 mile an hour wind would move that bullet 5.1 inchs sideways at 100yds with a 1600 fps muzzle velocity,so your groups were proably better than you though. Some of those new bonded gold dot Speers look interesting. Lee

Well thanks, guys - I was kind of afraid to even mention the size of the groups - but a number of them had a 5-8" horizontal spread, and I figured a good part of that was me. Now I can't wait to go back on a calm day!

IM jaybe

Jaybe: Glad to hear you got something working in
your ML. Sounds like the crosswind wasn't helping
much! Really good to hear you found something
that you can load without using a 16lb. sledge
hammer [:@] Keep me posted on results.
Danny

The wind speed was fluctuating on you. In a fairly steady wind, you will find your POI moved, but more precision (tighter grouping). At 50yards, I shot 1.75 spread groups with POI 4.5"-5.0" distant from POA. Wind was pretty steady though, around 25 mph.

It's great to see you are getting good results from your new Beartooth. Looking forward to seeing a photo of the deer you take with it this coming season.

Happy Hunting, Phil