Hey Rick, since we are not engineering for NASA, the level of precision might be less than they expect...
If the old master gunsmith that I apprenticed under 38 years ago thought that I would would take the time to set up a milling attachment to hone .050 inches off the side of a new spring instead of putting the flat steel in the vise and filing it down the appropriate amount he would probably turn over in his grave... and think that he wasted his time with me. Before he would trust me to work on a customer's gun with tools I had to pass his "test"...
Take a sawn off piece of steel bar that was larger than an inch in cross section and from it, create a 1.0" cube that didn't vary in dimensions more than .005" and that is no typo... Using only the vise and files.
I wish I could remember what happened to that cube... I used to keep it on my desk to remind me about doing precise work. Now only the memory has to suffice. Thanks for your input, Rick... it always opens my eyes.
I don't have a milling attachment yet... but will eventually... in the mean time making only .050 inches protrude above the flat vise jaws and laying waste to it with a file will have to do. Now, if I was going into immediate production on these springs... I would tell a different story... but first I have to make ONE and be satisfied that the investment will be worth it.