This is kind of a carry on from the magazine thread which has kind of ground to a halt while this bit gets done. For starters the hardest bit has been getting the barrel out of the receiver, that was tight and the thread had kind of picked up on itself.
Anyway the first step was to cut the barrel down a bit and drill a bigger hole through it, I was all ready to make a D-bit but a 10mm jobber drill very carefully welded to a rod worked fine
The next step was to port the barrel, I ended up doing 7 rows of 3.3mm holes, the 3.3mm panel drills were the cheapest way to go here, I only broke 3 ends as well. I drilled the holes with the barrel in the lathe (in low gear its pretty much locked up), that is why there is 7 rows as the hi low gear has 98 teeth, not the most useful number. The drill bit was held with an Aliexpress ER16 chuck that came with a little block with some bearings that I mounted in the tool post, the holes are also angled back at 75 degrees to the barrel axis.
Next was reaming to close to size, a 13/32 reamer takes it out to .406, I had to weld a rod to the reamer and welded the top of an old spark plug socket to that so I could use a 3/8 ratchet
Bookmarks