I want to buy hard cast bullets for my 629-6 and I want to measure the cylinder throats first. Other than an unsatisfactory attempt to slug the barrel of my .357 revolver, I have not done this kind of measurement before. I have plug gauges for .427,.428, .429, .430 and .431 in my shopping cart for MSC. They are all "plus" pins.

Does this sound like enough different pins to cover the possibilities?

Should I get the "minus" pins as well?