TC Strike accuracy loads.

ive looked up your gun and it has a 1/28 twist. it requires a bullet that is 600 grains at least but will shoot a 700 grain bullet also. if your shooting pistol bullets in a sabot they are way too short and spin out. if their is a commercial bullet that is as long as a 600 grain cast 50 cal bullet it will shoot well. now to really shoot your high quality gun very well get 600 grain paperpatch bullets from buffalo arms on the internet. they make and sell swagged ones. mostlikely they will be .492 in diam. then use the single wrap as you shoot, not prewrapped using 18 pound freezer wrap paper. you will have to use a 60 thousands thick wad which buffalo arms sells also between powder and the bullets base. 80 grains of powder should to the trick. pm me and i will get with you by phone or email to give you step by step how to do it. what im telling you will give you accuracy as far out as you want it. its not rocket science and very easy to learn and do.

been thinking about your gun, also if you get from mmp sabot co on the internet their sabot for a 50 cal that holds a .458 bullet not the one for the 451 or 452 bullet then for that sabot get some ungreased 45/70 .458 bullets of 400 grain weight. wipe between rounds and that combo will shoot like a house a fire to any range you want. use a good range rod, home made or boughten and dont use the rods that come with the gun to set the bullet. their you are, you wanted info to shoot your gun as you expected to shoot. you have a couple of choises.

I have a T/C Encore Pro Hunter (1/28 barrel) that I just sighted in (again) this past Monday at 100 yards for the upcoming deer season. Over time, I have found that the thing did not like 209 or 777 - it did not like Power Belt or SST bullets - it seemed to shoot all over the place (meaning 3 to 6” groups). So Monday I tried Pyrodex pellets (100 grains) and 250 grain Shockwave bullets with the black sabot.
For some reason unknown to me, the rifle loved that combo. Once I got the scope (Leupold VX 3i 3.5-10x40) settled into a 100 yard bull, my last 5 shots punched one ragged hole in the center X. After all of my shooting with other combos, I was tickled and amazed.
As I have always done between shots, I swabbed with a wet patch followed by a dry one, put one 209 thru the breech plug to ensure dryness and I used a range rod for loading. The thing shot as good as I would expect any centerfire rifle to shoot. Also what I find important, to keep your breech plug channel clean/ open (I use a 1/8” drill bit - the crusty residue builds quickly and seems as hard as concrete sometimes - I think that breech plug constriction may have been part of my problem all along). I hope this info helps with your frustration.

I would recommend trying a different powder, bullet or sabot.
Some folks find 777 to be inconsistent or erratic while others don't.
It's said that it can be more sensitive to heavy compression so try to only lightly compress it.
You would think that Blackhorn would perform well but the first shot can be a flier if the barrel is totally clean.
There's also American Pioneer Powder and its clones, Black MZ and Jim Shockey's Gold.

I think that lighter bullets are better, but the important thing is to find the combo. that your gun likes.
There's also different types and diameters of sabots.
MMP offers several different ones and Harvester sabots differ by having ribs.

Once you test out a combo., try to only change one variable at a time so that you can note whether there's any improvement
Sometimes there's a need for different performance requirements between hunting and target shooting.
For hunting, a very accurate and consistent 1st shot out of a cold and/or clean barrel can be more desirable than group size.
For target shooting, a heavier than necessary bullet may not really be needed just to punch paper.

Even the temperature of the barrel or how much the powder is compacted can affect accuracy.
Perhaps the consistent powder compression of pellets contributed to the exceptionally great groups that Steve S. was able to obtain.

When testing ammo for accuracy, why not test at closer distances to help eliminate shooter error.
There's a lot less variables that need to be controlled than when testing at longer range.
I suggest testing at moderate range first to see if you can close the groups up that way before moving the target out to long range.
Scopes can also contribute to sighting errors at longer distances.
IMO testing somewhere between 50-75 yards should provide a better indication of group size than 100 yards would.
Keep the paper targets as a record of your load testing at different distances.

How difficult is it to seat your sabot? If it's relatively easy, your going to have issues.
The amount of compaction isn't as important as keeping it identical every time. I lean on my rod to seat it tight, then I bounce the rod to make sure I get the same amount of bounce. With practice you can tell when it is right.
I have a variety of mmp sabots and bullets. If you want a care package, pm me your name and address.

Good to hear. My T/Cs have been rock solid shooters through the years from the New Englander to the Encore Pro Hunter and Impact. Both my parents and my son hunt Impacts now using Barnes TMZ 250s with 2 50gr Pyrodex pellets while I prefer the 250gr T/C Shockwave and 150gr in the Pro Hunter. Before that was Triple 7 and a flyer every couple rounds.

If your breech plug is pitted or damaged in any way I’d recommend contacting T/C for a free replacement under warranty. They may hem and haw but they sent me one, just make sure to specify model. If using a drill bit remember not to run it with a drill, hand pressure only will prevent damage. I prefer a small brush after a good soaking in Hoppe solvent (muzzleloader specific formula) or No 13.

I know I’m late to this party but... I have an LHR Redemption, which is the TC strike. It likes 100 gr. Blackhorn 209 by volume, with a harvester crush rib sabot, .452 for a .50 cal. I use either a Hornady xtp or sst in the 300 gr. version and a CCI or Winchester full strength 209 primer. LHR also sold a breech plug made for loose powder which I am using, not sure if that matters, the original plug worked fine too as far as ignition with blackhorn209. If TC has a loose powder breech plug id give that a try. Also the 250 gr. bullets did not shoot as well no mater what charge weight I tried. The bull in my avatar was taken at 209 yards with this combo!