The 7mm TCU Pistol Cartridge
By Chuck Hawks
Wes Ugalde designed the 7mm TCU at the request of Thompson/Center for the Thompson/Center Contender single shot pistol. The 7mm (There are also 6mm and 6.5mm versions of the same basic case) was first envisioned as a cartridge for the sport of steel silhouette shooting. It has been quite successful for that purpose, and also as a CXP2 class game hunting cartridge.
7mm TCU brass is created by first necking-up a .223 Remington case to accept .284" bullets (use a tapered neck expander). Then use a starting load to fire-form the necked-up case in a Contender with a 7mm TCU chamber. That's all there is to creating 7mm TCU cases. Once the case has been formed, it is best just to neck size for subsequent reloads. Note that T/C cautions against the use of 5.56mm military cases as the starting point for the TCU wildcats.
Here are the basic cartridge dimensions: .378" rim diameter, .376" head diameter, shoulder angle 40 degrees, shoulder diameter .369", neck diameter .310". The maximum case length is 1.760" and the overall cartridge length should be no greater than 2.675".
The Hodgdon Data Manual, 26th Edition shows that a starter load of 24.0 grains of H4895 powder will drive a 120 grain bullet at a MV of 1818 fps from a 14" pistol barrel. A maximum charge of 26.0 grains of H4895 will drive the same 120 grain bullet at a MV of 2020 fps. Both of these Hodgdon loads used small rifle primers.
The 7mm TCU case has about the optimum capacity for a 14" pistol barrel. It has been used successfully in the field on the smaller species of deer and antelope with various 115-130 grain bullets. Its recoil is moderate, and that allows accurate bullet placement, which is the biggest single factor in killing power.
Copyright 2006, 2014 by Chuck Hawks. All rights reserved.