.30 T/C (using Hornady bullets)
Date: Mar 16 2020
The .30 Thompson/Center cartridge was a joint development between Hornady and Thompson/Center Arms for that company’s ICON bolt-action rifle but is also chambered in the Encore single-shot rifle. In spite of having a relatively small case capacity, it offers ballistics that approach the .308 Winchester and .30-06 with 130- through 190-grain bullets.
Like many other "short cartridge" developments, the .30 T/C offers outstanding accuracy, while producing unusually low extreme spreads. It is easy to handload and factory load performance (which is loaded with proprietary blended powder) was essentially duplicated with several canister grade powders. Top performers in terms of velocity and accuracy included Accurate A-2520, Western Powders TAC, Vihtavuori N-140, Hodgdon BL-C(2) and Varget.
It is strongly suggested to begin with "starting" loads rather than "maximum" loads, then slowly increase powder charges while watching for signs of excessive pressure. Some reloading manuals publish heavier charges than listed here; however, those heavier charges were found to be excessive, with blown primers etc. in the Thompson/Center Encore test rifle. In several instances, when the powder charge was increased by just .5 grain, a safe load became an excessive pressure load. Again, small changes in powder charge weight can make significant changes in velocity and pressure…a pressure curve that was not always predictable. It is also suggested to use the exact components (primer, case and bullets) as listed in the accompanying data, as substitutions will have an effect on pressures.
Nonetheless, the .30 T/C is an outstanding cartridge that offers performance and accuracy.