I am shooting a TC triumph bone collector with a leupold ultimate slam. I am loading it with 100gr of Blackhorn 209 powder, barnes 250 TMZ bullet, and federals 209A primer.

My question is.... Should I sight in with a clean bore? Or should I sight in with the bore that has been fouled (two shots)?

The powder that I am using is the Blackhorn 209 and does not require immediate cleaning and is not corrosive to the barrel.

Looks like you already have it where it needs to be. A cold bore shot will general be a little off and then settle in. As long as you know where it impacts then you can compansate for it on the initial first shot. No more than it is off it still will make it in the vitals without adjusting for it at that same range.

When sightening in, I swab between every shot because when I take it hunting it has a clean bore first shot. I know that the second and third shot may drop a litte due to residue in the barrel without swabing.

What distance are you trying to sight in at?

I am shooting at a 100 yards

I would say get it sighted in and looks like you have it there, when you go hunting shoot one round to make sure that its dead on when you get to the hunting grounds.

then run one dry patch up and down the bore to leave a little fowling

Thats what I do and I find it to be more accurate with a little residue in the bore and I have a T/C triumph as well.

Question- Is blackhorn 209 a loose grain powder or a pellet?

The same approach and theory I have on sighting mine.

I just bought a TC Omega with the Nikon Omega scope. WIll be sighting mine in this weekend and was planning on using the same powder (Blackhorn 209) and the Barnes 285 TMZ. The guy I bought it from told me that he found it had better accuracy after shooting it a time or two. He said he would shoot it, dry swab it, fire a primer in it, then load it to go hunt.

The Blackhorn 209 powder is loose. I went and shot again this time using the same load with the TC shockwave 250 gr super glide bullets instead of the Barnes. I am simply amazed of the accurcy of this gun. I can put 3 shots in the group of .75". I am going to try to up my powder load to 110gr or 120gr and see how that shoots.

I used to shoot a fouling shot((powder primer only) . But some times you will not have or be allowed that opportunity.
In that case you'll know ahead and should consider a swabbed bore/clean bore for your sight in.

Oh good to see Carter Country is still around.
What is that on 105,1314??? , been awhile since I been that way?

The carters I go to is in spring tx. The range off of 1314 is called Thunder range and the range off of 105 I think is in conroe tx. I am going to Thunder rage this weekend because they have 100yd 200yds and 300yds and I want to see how my new gun works at 200yds.

Only one of my two local ranges has range in excess of 100 that's Gibsons of Lawson Rd and he has 200yds but charges double range fee nowadays for it. The other range a city range only allows sp and HP ammo and only goes to 100yds.
I can sight in at our seasonal lease as far as I care to up to 600-700yds easy but never have needed anything past 200yds very often..with my actual longest shot being 220yds most under 150 at least half inside of 75yds even. Course this concerns cf ammo though. My longest Muzeloadrshot was 70yds maybe. and witha TCCugar Hawken 370gr conical.90gr fffg Goex.
Having a 300yd range would be nice for any type of firearm.They have a golf-cart or ATV to go do and switch targets with?