I am currently shooting a SST Super 14 .223 G2 Contender Handgun, and a SST 23" Bull G2 Contender Rifle.
When I acquired both of these guns I had a bunch of ammo loaded with 55gr. Nosler Ballistic Tips (H-4895 Powder 1/2 grain under Hodgdon's published max on their web site, Military LC Brass / Remington 7 1/2 Primers) left over from a previous .223.
Of these two T/C's I have shot the Handgun the most, largely because I just acquired the Rifle a few weeks ago. One day in December it was a beautifui day for northeast South Dakota. 40 degrees and NO WIND so I headed for the range. My plan was to verify my zero and shoot some groups with the 3x12x Burris LER Handgun Scope set at different magnifications to see if I had any point of impact shift at different magnifications.
I shot 6 - 3 shot groups that afternoon from the bench at 100 yards at magnifications ranging from 6x to 12x. The smallest group of the day measured .238" and the largest group that day measured .500", with the rest of the groups being between that spread. For the record this load out of my Super 14 .223 Handgun averages 2820 FPS 12 feet from the muzzle.
As stated I haven't shot the T/C .223 Rifle much as yet, and am still breaking in the barrel. So far the groups I have shot have been under an inch.
Good luck with the T/C .223.
Larry