Wanted to try the bullets that came with my Omega today. They are afew years old, had a Thompson logo (I think), appear to be XTP 300s with a black sabot. Very hard to load in my barrel. Not a chance of getting them down the barrel with the glass range rod. Had a hard time getting them started with the metal rod too.

Groups were very poor. Switched to Powerbelt 295s and the groups were better. The Powerbelts shot about 6 inches higher at 100 yards.

Picked up some of the black crushed rib sabots and they fit the XTPs much better than the other black sabots that I have. Seems like the base of the older black sabotsare too small for the bullet.

Are all black sabots supposed tofit the same sized bullets? Like Purple for 16 gauge, Yellow for 20, and Red for 12?

No, they are not all the same...The black sabots are made for .451-.452 diameter bullets, but the thickness of the sabots can be different...MMP-24s are thicker than MMP-12s...

There can also be differences in the bases, petals, ribs or slick, etc as well...

No, not all black sabots are the same size. For example MMP12, MMP24 and MMP 3PetalEZ are all black but they vary in sabot thickness. Getting the proper "Goldilocks" fit between sabot and bullet is critical to accuracy, too loose and they rarely seal the bore and shoot accurate, too tight they are difficult go get down the bore and also no 2nd shot in the field is possible. So what is "just right", I would say what you experienced with the crushed rib is "just right". Also just because it says on thepackage for.452 diameter bullets, several of us that have Savages are shooting .458 bullets (Barnes Origonals,Flatbase)with .452 CR sabots. They appear to be "Goldilocks" right for the .458 in my Savage. I do shoot the CR with .452 Noslers and .452 Gold Dots in my TC Omega and Knight Disc. Best thing you can do is have 1 package of each of the following:
MMP shot black
MMP12
MMP24
MMP 3petal EZ
Harvester Black
Harverster CR
Harvester CR for Smokeless

The CR for Smokeless are VERY thick, so if you have a very undersized bullet (like the .450 Parker Ballistic Extreme), the red sabot may shoot it "just right" for you.

Usually when I am shooting a new bullet I try 3 different sabots, for a .458 bullet I try CR, 3Petal EZ and Orange MMP made for the .458. With .452 bullets I try the supplied sabot, the MMP12, 24 and CR.

See my post from a couple of weeks ago on shooting CR, Orange and 3PetalEZ in Savage with Barnes Origonal.

See this little experiment that Semisane did a while back, he shot like 5 or 6 different sabots with the same gun, bullet, load and primer--results vary drastically: http://tinyurl.com/2qen2s

Chap Gleason

Unfortunately since there is no standard to barrel bore diameter in muzzleloaders... they use the "as long as its close to" measurements... there is the need for different thickness of sabots. They vary by manufacturer, their ability to handle magnum charges VS regular charges, and their thickness of course. Be very sure of the diameter of your bore. Slug the barrel if you have to. Then pick a sabot to match the kind of projectile you want to shoot that will give you a firm tight, pressure sealing fit. I am not saying you have to drive the thing down the bore with a hammer mind you, but in a sabots case, too loose can often mean poor accuracy.

Sabotloader is a good source of information on sabots. I go to him when there is a rifle, sabot/bullet combination that just does not seem to work. He normally has good advise, and seems always willing to help. No matter how many times I have asked.

My Encore loads very hard with the 250 grain SST in the black and red sabots:The gun does shoot like a dream with those loads. The Hornady Low Drag sabots shoot less well but are acceptable for most hunting. That Encore does not like the Super Glides at all: Groups are about 6" at 100 yards.

falcon

Normally the SST's come with an HPH-12 sabot but there are rumors that the NEW packages of them come with HPH-24's - I have not confirmed that with Del yet. So, normally I would say if you are shooting SST's then the next sabot down is either the Harvester regular short or long black, or the HPH-24 - dropping to the "low drag", the "Easy Glide", the 3p-Ez load. or the "crush rib" will probably cause a bit of loss of accuracy, actually pressure also.

Confirm something for if you would, are the red "low drags" a 3 or 4 petal sabot? I am operating under the assumption that they are a 3 petal sabot. + they should have stair stepped powder cup - or are they a smooth cup.

So if I were moving from a SST sabot I would go to a MMP HPH-24 and try that - it should load easier than the 12 and accuracy should really remain close.

Just my observation... (actually I am surprised you can get a HPH-12 SST sabot down the barrel of your Encore at all)