as a buyer of the bags from the count machines, I've seen some really wierd stuff.
one branch seems to have the machine being spot on while others are not so much. in the branch that was spot on, the dimes contained fewer silver and almost no canadian. The quarter bags (2) were spot on correct containing 1 silver washington and 1 silver canadian.
The other branch is a little less accurate and I've brought it to their attention. One bag of dimes ($1000) not only contained 23 pennies, 2 buttons, a safety pin and a picture hanger, but also was short by $3 in dimes. Several other bags from them of dimes almost always contain anywhere from 1 to 25 pennies, nickel bags almost always contain 1 or 2 pennies. Penny bags seem to include a dime or two.
The branch that I deposit to runs them through their machine and I take their count as accurate. I figure any inaccuracies in the long run will likely work out to be a wash (win some, lose some) and I'm not about to sit here and count all that I give them. I have a rough idea and so long as we are close, thats fine. The last time I gave them stuff it ended in 4 cents. I asked them and they said "must have been 4 pennies". But I knew that there had only been dimes, so the machine counted 4 of them wrong. I told the teller that, but she assured me the machine was accurate and that I must have thrown them in there...
I used to drop off an average persons amount of change in this same counter and I counted it prior to dropping it off, and sure enough it goofed a few dimes for pennies.
I didn't know that they were subject to the weights and measures people - that's good to know though. Based on the condition of several coins, I'm not surprised when things get counted wrong. Some of the pennies in the bag of dimes were shaved to be the size of dimes (yup just like the guy who got pardoned), and some were just rough shape. In the nickels you see some that look like hell.
So are they 100% accurate - I would say NO WAY. Do I think that their level of accuracy fall within a reasonable amount considering what they are up against - yes. I think its a risk we take as roll hunters that what we buy site un seen might not be what we think it is. It also might be what they think it is (it might be silver). Every branch I've spoken to said that their machine is verified and serviced at least once a month.