Just like every person is different, every bore is different so get some different sabots and load the bullet you want to shot in the sabot for a tight fit and SWAB between shots. Sabots you should buy:

MMP HPH12, HPH24 and 3petal Ezload from here:
http://www.mmpsabots.com/

Then get some Crushed Rib sabots from MidSouth Shooters Supply:

http://www.midsouthshooterssupply.com/item.asp?sku=00072H15045BR

I would shoot an accurate penetrating bullet, like a Nosler Partition, Barnes MZ or TMZ or Speer Gold Dot:

http://www.midsouthshooterssupply.com/item.asp?sku=0011545350

http://www.midsouthshooterssupply.com/item.asp?sku=0003545162

http://www.midsouthshooterssupply.com/item.asp?sku=000213974

You will not have trouble with these bullets on penetration and expansion with no fragmentation.

Take your breech plug out of your gun and load and with a clean barrel load 1 bullet and 1 sabot combination in your gun, write it down for how much pressure it takes to push the bullet down the gun.

Examples of loading pressure:

very easy---falls down the bore easily, 1 finger can push it down
easy--------push down with little effort
goes easy but effort required--push down with some effort
goes down hard---push downbut hard to start in barrel and you got put your weight into itto get to down
hard-----have to drive itdown the barrel with a hammer, "almost broke my ram rod"

A sabot bullet combination should be tight, like goes down hard, but does not require pounding it down the bore.In my experience the crushed ribs performed well in my inline BP guns--they went down snug, was not a lot of pressue to load them, and they shot accurate. In my Savage shooting smokeless I had to use an MMPHPH12 to get .450 Parker Ballistic Extremes to shoot well i.e. they loaded "just right". So think "I need a Goldilocks Sabot (just right, not too easy or too hard)for a givenbullet in my gun."

Once you find the right combination of sabot for your bore and your bullet, shoot the bullet at the range for accuracy. Shoot hunting load, i.e. 100g of 777 or pyrdex, whatever is your load in your gun. Note very seldom is 150g of powder required for best accuracy---read the gun makers book and find out what bullet they recommend and sabot they recommend in their gun and shoot that first for grouping, then you know what the rifle is capable of, since no rifle maker is going to ship an inaccurate rifle/bullet combination. You may have to go down to 80 or 90g for best accuracy. A 3" group at 100 yards is considered good hunting accuracy.
Chap Gleason