The head space measured at just under .050", I have read that they typically run about .055" so this one may have been machined, which might explain why it was polished.
Optimal head space is between .044 and .047. Since this one is close, we will leave it as is for now.
One of the things often done to 10/22 bolts is installing a pin above the firing pin channel to prevent it from lifting up. By forcing the pin to travel in a straight line you end up with more consistent strikes to the rim, which is supposed to result in better precision.
Most of the aftermarket bolt makers have a pin pre-installed, like this one from JWH Custom (note the red circle)
You may ask why I didn't just buy one of their bolts with these mods already performed. I could have done that and stayed within the budget (it would have impacted our budget by an additional $60 or so), but the point of this built is to do it ourselves. After all, anyone can get out the credit card and buy a custom rifle or buy the parts pre-made.
The first step was to get the machinist vice clamped down and checked for level, then check to make sure I have the proper clearance to move the vice.
I left the level in place while drilling to make sure the bolt was not shifting.