A couple of notes on tumblers.
The vibratory tumblers are faster than the rotary. Burnishing
1/2 hr. Longer won’t hurt but doesn’t buy much in improved shine.
Check with gun shops or reloaders suppliers, they sometimes have
much better prices on the same units than jewelers suppiers.
Reloaders use tumblers for polishing cartridge cases prior to
Thunderbird Supply (800-545-7968, http://www.tbscorp.com,
e-mail, firstname.lastname@example.org) has mixed shapes of stainless steel
shot for about $11.00/#, carbon steel about $5.00/#. They also
have a small vibratory tumbler for around $70.00. It uses 6# of
shot. I’ve used this model for about 6 yrs with no problems.
I’m not connected with TBS, just a satisfied customer.