STI throats are on the long side because a lot of buyers shoot 9mm to major power factor and load them on the long side.
That being said I have tested my 9mm Trojan out of my Ransom Rest, and the most accurate lead bullet load is a 125 grain (actually weighs in at 122 grains) Missouri Bullet SWC over 5.0 to 5.1 grains of AA #5 @ 1.100" OAL. It shoots groups in the 0.8" to 1.5" range @ 25 yards all day long. I did not try Unique. You might want to give AA #5 a try with your TC bullet.
That bullet in your picture doesn't look like it has any lube in the lube groove shown in the picture. Do the bullets have lube in another groove that can't be seen? As far as I know lead bullets will require lube to perform adequately.
Last edited by jbrown13; January 25, 2012 at 10:46 PM.