Author Topic: barrel porting (Read 541 times)

maggot · « **on:** June 03, 2003, 06:50:37 PM »

Has anyone here ported thier barrel.I know some companies use an EDM but has anyone had any luck using a carbide endmill?

KN · « **Reply #1 on:** June 03, 2003, 08:30:18 PM »

I have done several this way. The only draw back is that no matter how careful you are you will have a burr inside the hole. I pre-drill the holes about .010" undersize and then finish with a good carbide end mill. Gun barrels are tough material to get a good clean hole in. I have some burr balls that I shortened the shanks on so I could get them through from the inside and de-burr the holes but you'll still have a very small burr left from the burr ball. Fire lapping a few rounds will smooth this up. Do this on a mill and not a drill press. And be sure your setup is good and rigid. Hope this helps. KN

maggot · « **Reply #2 on:** June 04, 2003, 07:03:42 PM »

Hey KN can you recomend a pattern and hole size.I'd like to do my .300 win mag.I think the less holes the better, so I don't screw up!Also should I even bother deburring if I'm going to fire lapp?

KN · « **Reply #3 on:** June 04, 2003, 07:56:11 PM »

I usually use about a 3/32 dia. and I put 5 holes along each side at 90deg from top. I also drill these at a 10deg rearward angle so that it is pushing the end of the barrel when firing. Then I will put 4 holes along each side at about 30 to 45deg (depending on the sight) square with the bore and located in between each of the 5 holes on the side. this is to reduce muzzle jump. I also put a fairly good chamfer on the holes for cosmetic reasons. I just happen to have a pic I can e-mail you but I need an address. KN