gunfun 3,931 Posted April 18, 2013 Report Share Posted April 18, 2013 Short punches are harder to break and better for starting stubborn pins. -And Dubya I've still got a year left. The congratulations are premature. In fact, I don't think they will really be due until I've paid school off. That's when I will be really free to make trouble. Quote Link to post Share on other sites
fbg_firebug 1 Posted April 21, 2013 Author Report Share Posted April 21, 2013 Definitely pull the block, check the ports, reprofile and polish internals. Then shoot it and see what you got before you spend unnecessary money. I agree, I wouldn't send anything in to get polished until you get the gas ports right and just polish off the paint on the rails, hammer and bolt carrier yourself. You'll end up spending about $150 to send it off for a shiny polish job and likely wait 1-3 months for your parts back... What size drill bit fits tightest into your ports? I was able to get a 5/64" bit in all three holes. Quote Link to post Share on other sites
dubya 198 Posted April 21, 2013 Report Share Posted April 21, 2013 (edited) Definitely pull the block, check the ports, reprofile and polish internals. Then shoot it and see what you got before you spend unnecessary money. I agree, I wouldn't send anything in to get polished until you get the gas ports right and just polish off the paint on the rails, hammer and bolt carrier yourself. You'll end up spending about $150 to send it off for a shiny polish job and likely wait 1-3 months for your parts back... What size drill bit fits tightest into your ports? I was able to get a 5/64" bit in all three holes.So they're .078", if it's not running 100% with bulk ammo like you want I'd open them to .093" but that's me, one member may say different. I have 4 @ .093 and one @ .078 and it runs great but I'm also cutting a little over 3" off my barrel soon. Get a good Cobalt 3/32 bit and open them things up! Edited April 21, 2013 by dubya Quote Link to post Share on other sites
fbg_firebug 1 Posted April 21, 2013 Author Report Share Posted April 21, 2013 That's going to have to wait till I can get with a friend and borrow his drill press. Don't think I have steady enough hands to do it with my hand drill I have. Quote Link to post Share on other sites
dubya 198 Posted April 21, 2013 Report Share Posted April 21, 2013 If you have a bench vise it's actually very easy. Just put a toothpick or something else small in a port and angle the barrel/gun until the toothpick (ports) are perfectly vertical, then you can drill straight down. It's really easy to do with a hand drill. Here's a pic of when I did mine.... 2 Quote Link to post Share on other sites
gunfun 3,931 Posted April 21, 2013 Report Share Posted April 21, 2013 I'd still go to an intermediary size like .082 or .084 before going so large a .093. Further, this job doesn't need cobalt. Any HSS bit will cut S12 barrels. They are tough, not hard. Quote Link to post Share on other sites
fbg_firebug 1 Posted April 21, 2013 Author Report Share Posted April 21, 2013 Thanks for the information. I'll be trying this in the morning before church! Quote Link to post Share on other sites
dubya 198 Posted April 21, 2013 Report Share Posted April 21, 2013 (edited) Yeah trying smaller first is more than likely the smart way to go but you'll probably need 093 to run perfect. Actually adding a fourth port at 078 may be a better idea. Anyone? Edited April 21, 2013 by dubya Quote Link to post Share on other sites
gunfun 3,931 Posted April 21, 2013 Report Share Posted April 21, 2013 I thought he had 4 already. If not, then definitely as long as you can fit it cleanly into the shadow of the gas block opening. Quote Link to post Share on other sites
dubya 198 Posted April 21, 2013 Report Share Posted April 21, 2013 I thought he had 4 already. If not, then definitely as long as you can fit it cleanly into the shadow of the gas block opening. Maybe I read wrong.. I thought it was three. Anyway, if the fourth (if its not there already) is needed and the GB opening isn't big enough you may need to open it a TEENY bit. There are a few threads on it but if you do need to open it up make sure you read up before doing so because a few ppl have messed it up without researching beforehand. Quote Link to post Share on other sites
fbg_firebug 1 Posted April 21, 2013 Author Report Share Posted April 21, 2013 I only have three ports. Not sure if I can get a fourth one in the shadow of the gas block. The three are pretty well spaced out. Sorry the pictures are not that good. Might be able to get one at the bottom and make a diamond but then I'm kinda worried about the piece of barrel in the middle being weakened and breaking. Quote Link to post Share on other sites
Terminator03 18 Posted April 22, 2013 Report Share Posted April 22, 2013 You can easily add the 4th hole with no problem at all. I actually had 4, but the 4th one (that you are missing) wasn't drilled all the way through, and was very slightly shrouded by the gas block opening. I just filed the opening in the gas block at an angle to unshroud the bottom where it interfaces with the barrel, but didn't really change the opening inside the block. I agree with others that the "D" port is unnecessary, and potentially harmful. Don't worry about that diamond shape breaking after drilling because most are done that way from the factory. Quote Link to post Share on other sites
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