Quote Originally Posted by r29l20
Have you ever seen a bolt that was cleaned with a tap.
Sure haven't because you can't do anything to a bolt with a tap.
Thompson Center has a breech plug shaped thread cleaner, it's made of plastic.
You assume that this is a matter of suitability, I'd argue that it's one of cost. A metal plug tap that size would make up a substantial portion of the cost of the rifle. Repeated use of a metal part over time would likely wear the threads out but a single use shouldn't hurt anything.

Cleaning threads and cleaning up threads are two totally different things. Cleaning threads means *removing* foreign material from them. Cleaning up threads means *fixing* threads that have been boogered up in some manner. In the first instance, I really want to remove material and unless the threads are boogered as well, the material being removed shouldn't be the material of the threads but rather only the foreign matter. In the second case, you are correct, I want to "iron out" the messed up part and press the displaced material back where it should be. This should ideally be done on a clean thread or the foreign material will get ironed into the surface and trash the threads. The first can be done with a tap (special taps are made specifically for cleaning inside thread that have a larger than normal debris channels but are no less sharp than a thread cutting tap), the second with a thread restoring tool.