I was given a Lyman 1200 DPS by a bloke who was leaving the area. It is a early model from their range.
I also have a Sartorius analytical balance which I got from a previous job as it was over two years old and being upgraded. It is a true balance and not a load cell.
The Sartorius is good for good for 3 decimal places and the rounding only take place after the third decimal point. Both balances are checked by lab quality test weights.
What Chronos and Blackened have said is right on the money. Cheaper digital scales will round your results and can "stick" if trickling.
For a half decent explaination of this with shooters in mind, have a look at this,
http://m.youtube.com/watch?v=zxMzbAt4bj0The Lyman is OK in relation to consistency. ( I have not tried any other type of trickle system) With a static test weight the load cell will read true weight but as for trickling it will do 0.1 grain but not conststantly. It is always within 0.2 consistently.. This could be close to 0.4 without the rounding effect.
All that said, if you have a high capacity case and am dumping say, 50 grains, 0.2 of a grain is only 0.4%. You will not see any great if any change in POI.
If you only want a charge of 10 grains, 0.2 of a grain is a 2.0% difference. Small case capacity does not leave a lot of room for error. Min and Max can be as little a 0.6 of a grain with some powders.
I have a RCBS balance beam but I have not pulled it out for years as it is very slow compared to the electronic one.
You tend to check everything when you have the ability to do it fast. The problem that I have with 3 decimal places is that you see the error between components and this plays with your mind if you have OCD. You have to keep telling your self that the last two digits are so small that it is almost impossible to control.
Bill
Swaging your own projectiles is the ultimate in flexibility.