Anyone can, including you! All you need is the reamer, tap wrench to turn the reamer, proper cutting oil and a dial caliper. Do not try to use WD-40!!!!!
Start by measuring the distance from the front of the cylinder to the head of a new10mm case or factory cartridge inserted in the chamber. Check all of the chambers and use the shortest dimension. Record that figure, you will need it again for the next step. Ream the chambers until a 10mm Magnum case or cartridge gives the same length as the 10 mm case did. Only turn the reamer 2-3 turns, remove, clean and go another 2-3 turns. Be sure to apply cutting oil between cleanings. Measure carefully when you get close to full depth and then carefully finish the last few thousandths. Do not apply heavy pressure to the reamer to get it to cut faster, just enough to feel it is cutting or you can cause pinning of the reamer and scoring of the chamber! Remember, you can't put metal back if you go too far.
You should not have to polish the finished chamber if the reaming is done carefully with a new reamer.
I would recommend buying the reamer from Manson, he has better pricing often. Or just "Google" chamber reamer makers. Or Google chamber reamer rentals. I recommend buying a new reamer, you may get a damaged or dull reamer from a rental company! Probably not, but why chance it.
Between the gunsmiths fee, and shipping both ways, you will save enough to pay for the reamer. Besides, you only have to wait a few days for the reamer to arrive instead of months sending it to a gunsmith!
