I have an older Prohunter, the one with the nut on top of the breech plug, not the knurled end. Needs a socket type tool to instal. I decided to replace the breech plug after several years of shooting. The new breech plug twists in but does not tighten far enough in order for primer to drop in and gun to close. The original one, twists in straight to "12 o'clock". The new one only twists in to about "11 o clock". And it is tight, as in there is no way to tighten it anymore to get it to "12 o'clock". I greased both the gun threads and plug and it didn't help. I also took the O ring off the plug to see if it would twist in further and that didn't help. It feels like it is at the end of the threads and cannot physically be twisted in any further. So I bought another new breech plug ($80 a piece in Canada), and this one slides in real easy and twists too far to "1 o'clock" giving me the same problem but on the opposite side, the primer won't seat in properly in order for the gun to close. I called TC and they could provide no assistance other than sending the gun in which is near impossible as I am in Canada. Had a couple gunsmiths look at it and they think it is the plugs not the gun, which I think is the case as well, but TC says the plugs are all the exact same. Any thoughts, ideas, suggestions?