Back in the day, I owned two of them. I thought they were going to be the perfect companion to my 45x209 barrels. I needed .50 cal to hunt in some states. The .50 cal was not the answer.
In order to keep pressures safe on the frame the breech plug is ridiculously long which really affects the flashhole and encourages inconsistent burn rate in my opinion.
As mentioned - the T/C QLA system is a solution for a non-existent problem. I had the QLAs turned off and the muzzles re-crowned on all 4 T/C Contender mzldr barrels. Much better accuracy, however, still not acceptable for me in the .50 cal version. Both barrels went down the road.
That being said, I am saddened with the demise of T/C mzldrs, especially sidelocks.