This is a 3d printable tool for lapping the locking lugs on a bolt for a large ring mauser. I used a 3/8" spring 1-1/4" long. A 1/2" bolt 1/2" long is used to adjust the tension on the spring. I have included a 3d printable bolt for those who don't have access to imperial hardware. After printing the internal 1/2" thread might need to be cleaned up with a tap. The printable 1/2" bolt can also be scaled on the x and y axis to get a looser fit.

Print Settings

Supports:

No

Infill:

Notes:

I printed at 0.1mm height and had no problems with the overhangs of the threads.