Mac,
We all have our pet theories and loads so here goes: it would be fair to say the all accuracy is is simple consistency and how consistently you use exactly the same technique each time you load the rifle will have more to do with consistent accuracy than any other variable. Consistent powder charges, bullet seating pressure etc all make a measurable difference downrange.
Another thing is that sabots have to be soft enough to load from the muzzle so they are a lot softer than shotgun sabots and generally do not like hot, or even warm, barrels. If you can feel heat on the barrel you'll want to let the fully barrel cool between shots while working up loads. I know it can be tedious but when you hunt it will be with a cold barrel so you should zero that way too.
TC rifles have the tightest bore in the industry. For the $6 or so a bag they cost I'd get a pack of the black Crushed Rib sabots from Harvester Muzzleloading. They are the most forgiving sabot I know of in terms of shooting well with various bullet and bore diameters.
I use a Savage smokeless powder rifle and can load .458 Barnes Originals with the black crush rob sabot. If it can handle the .006-.007" difference between that and the .451 and .452 bullets it will work fine for you without having to worry about a tight sabot and heavy ramrod pressures.
Another great sabot for tight bores is the Magnum Muzzleloading Products HPH-24. It is a couple thousandths of an inch smaller than normal specifically for tight bores such as the TC.
http://www.mmpsabots.com/http://www.harvesterbullets.com/Blackhorn 209 will cost you a lot less per shot than any of the pellets and does not have either the fouling issues or corrosion issues that many other powders have. It also is a lot less susceptible to picking up airborne moisture most other powders. I've used it in the Savage occasionally and in standard muzzleloaders full time (for my sons) for 3-4 seasons now. If you use it be sure to use a full power primer and not one of the "muzzleloading" primers.
Personally, while I've never lost a deer with a 240 or 250 grain XTP I've had very few exit wounds either and I want one so I use 275-300 grain bullets with which I've never not had an exit wound.
The three bullets I use most commonly are the 300 grain non-magnum Hornady XTP, the 275 grain Barnes XPB or the 300 grain Barnes .458 semi-spitzer Original.
The two Barnes bullets shoot 1 MOA or better to around 200 yards and the XTP shoots about 1 to 1-1/4 MOA out to around 150-160 yards, all out of the Savage. My experience has been that the non-magnum XTPs, either the 250 grain or the 300 grain bullet shoot somewhat more accurately than the 240 and 300 grain magnum variety. I doubt it matters to the deer or black bear though...
The 300 grain XTPs are around $30/100 and the sabots are generally less than $0.15 each so you can save a lot of money buying them separately and get the bullet/sabot combination that shoots best and loads easiest. The XTP in any weight is a heck of a value.
I currently have 250 grain non-magnum XTPs and 300 grain magnum XTPs on the shelf along with the black crush rib sabots and several kinds of MMP sabots including the HPH-24.
I know time is short but if you'll PM me an address I'll send you some of each to try out. I know it can get expensive to try all the different combinations and these are available if you want them.
Good luck and let me know if you want the supplies.
Lance
