One of the projects I'm working on is changing to thread size. Of my 54cal hawken. Changing it from the 6-1mm to 1/4-28. To make sure I have the right bit and tap, I ordered a set.just in case I mess up. I ordered two drums and alignment tool from tow. Talked to a guy that has done it.

The why.
There is a shop close to me that has a great deal on 1/4-28 nipples.