One of my early practice runs was to take a piece of heavy duty plastic/nylon? round stock and thread it for my reciever.
Once it fit the reciever, I decided to make a bolt lapping tool rather than purchase one. So, I did the following...
- found a .5"x4" spring at the tool store
- cut the length of the round stock to fit the spring
- bored the inside of the round stock to fit the spring, stopping about .5" short of the receiver shank
- bored a hole through the shank just shy of the bolt face dia
- made a plunger to fit the bore of the round stock with a nipple to fit the ID of the bolt face and about 1" long (.5" protruding towards the bot face)
- made a threaded end cap to capture/compress the spring and apply pressure to the plunger/nipple
It was good practice, and saved a few $$.
-- richard