As Keith said, TC has always followed sound business practice by being willing to let go of models no longer profitable for them, and bringing out new ones to replace them. And that applies to all their product lines. The barrels have changed over the years with customer demand and so sales. That demand is influenced in part by the shear numbers of what's already out there from TC that is still in serviceable condition up to near 44 years after it was made. How many shot-out Contender barrels have you ever heard about? In 43 years of owning them I could count the ones I have on less than one hand. So resales of used barrels effects new sales and TC doesn't try to compete with that. What cartridges they are chambered for has also changed over the years. New fads bring in new offerings, and when the fad wains so does sales and they are dropped. The cartridges designed for shooting IHMSA is an easy example. Some old standard chambers they have always offered remain, but many do not because customer demand changed. TC's only standard pistol barrels were 10" octagons for the first 5 years until customer demand brought out the 10" and 14"bulls, and they sold so well they eventually replaced the octagons completely. Obviously demand has changed again, so the 10" barrels have been dropped. FWIW, TC has also brought models back if customer demand appeared to warrant it. Most were short reissues though and were soon dropped again.
On the plus side there is probably a million plus 10" barrels out there, and many often come up for sale or trade. You can always shorten a 12", 14" 16" or 23" if your heart simply can't live without a short bull barrel, or have one made by a custom shop.
