I own a custom rifle making business. This thread is for discussion only so I'm leaving any association to my business out of it. I don't want the mods taking this as some guerrilla marketing effort.
So, here's how it starts. I have a Winchester Model 70 that is going to be accurized here at the shop. "Blueprinted" is another term commonly used for this. The work is typically done in a lathe, truing up lug surfaces, threads, etc. Not here. I use a cnc setup in a 5 axis format.
First, I have to qualify the bottom of the receiver. It must be flat so that the fixture to hold it for accurizing doesn't distort the part and create an error. This fixture registers the raceways parallel to the table so I can deck the bottom.
Now that were done with machining, we move onto a little cleanup and deburr work. I use a mill file and wrap it with some 180 grit emery. This just levels out any tool marks and puts a nice finish on it. Care must be taken not to get too carried away. If we take too much off in one spot it'll cause the receiver to distort when in the fixture.
Now onto "the rock" for a flatness inspection. This is called a surface plate. A ground/lapped piece of granite that is used as a reference table. The height stand and indicator will show any deviation as I slide it over the part. Were in good shape. Were hovering around .001" for flatness from end to end. That's pretty good for a mill. Any better and we'd have to surface grind the bottom. -much more work than the job warrants.
So, that wraps up 1st op. I'll mount the fixture and get more pics here in a few minutes.
More to come. . .