There is a lot of good and bad information in this thread. First, NEVER put any liquid lube in your action, lug included. These parts are intended to operate dry as per the T/C instruction manual. Lube collects grit etc that prevents proper operation. Clean it well with a degreasing spray.
Second, a light primer strike is usually caused by the shoulder being too far FORWARD, preventing the action from fully closing. This prevents the interlock safety from releasing the trigger block fully, blocking the hammer from maing a full hit. The other causes are usually a poorly-fitted barrel or faulty/dirty lug/breechface.
Since the OP had good luck with the barrel until recently, either his dies/press/brass have changed or are out of adjustment, the locking lug is dirty or damaged, or the action is so dirty from caked lube and dirt that it won't close. Possibly the lug spring has gotten weak, it should be replaced with a new one - and if the barrel does not have a two-piece lug it is time to make it so. My 1975-vintage .30 Herrett barrel is still going strong, but it has a stong lug spring and a 2-piece lug, and I keep it very clean.
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