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Discussion Starter #1 (Edited)
This is going to be my first build THAT I HAVE TO REMOVE THE RIVETS from the trunion. Could any of you give me some idea of removing the rivets without damaging the barrel, or should I remove the barrel? I really don't want to remove the barrel becouse of the factory set headspace, but I will if I have to. I just thought you guys would might have a better idea.
Thanks,
-Shadow-
 

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I have not done a full build yet but from what I understand is if you are doing a screw build then just drill em out a little and tap the holes and get screwing.... if you are doing a rivet build you will have to pull the barrle out.

Hope this help

Simian
 

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As I've read here, the key to drilling out the riviets and not damage the barrel is to grind the rivets near flush with the trunion. Center punch. Set a max depth on the drill press (I've seen one number that is the max depth but I won't repeat it here, because I don't know if there is variation between kit types). Start with a smaller drill bit and get a good center, work your way up in size until the shank (?) of the rivet is drilled out. I don't think there is any way to get the flattened part that is between the barrel and trunion out, but this doesn't effect the screw build as I've read. Now about the factory headspace, am I wrong in thinking that once you press the barrel back in and re-insert the pin you are back to the same headspace? I'd want to check it in all cases, even with a screw build I think. Of course my comments on drilling out the rivets are all hypothetical as I pressed the barrel out, ground flush the rivets and punched them out.
 

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The pin is such a close fit that it should return to its original position. In gunsmithing school they said a quick and dirty way to check headspace was to take a factory cartridge and put a piece of .004 feeler gauge on the back and close. Use a thicker piece and try to close again. If it appears correct tie the gun to a tire and use a string to fire a round, check the primer for crushing and repeat. Do this about 10 times. Of course you could end up with a parts kit all over your yard! I've had two guns blow in my hands from bad headspace, first a brand new Winchester .22 mag and another that was a customers .22 gallery rifle. The Winchester was ruined and I got a thumb full of brass. Personally, I'm using the Q&D method on my 3 kits cause they are all matching and I could buy 700 rounds of ammo for the price of the gauges. I want to build an Uzi and MP5 pistol after doing 4 AKs so I don't want to invest in gauges I won't use again. Depends on how much risk YOU want to assume.
 

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The barrel cross pin has already determinded your headspace. If you are able to remove the barrel, that's the best way to ensure that you don't drill into the trunnion or barrel (see attached picture). When removing the barrel make sure you mark both the barrel and trunnion with a wittness mark so that you can align the barrel and trunnion prior to installation.

Drilling the rivets out with the barrel still installed is more difficult.
 

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Discussion Starter #6
How about 1-Measure the depth. and 2-Using some sort of stop on the drill bits to guage the drilling depth so it doesn't go too deep to hit the barrel?
Other than tape that is.
 

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Myself I pull the barrel, mill the heads down on the rivet, center punch, drill 1/2-3/4 of the way through the rivet with an 1/8" bit and then punch them out with a punch of the appropriate size. I have seen one guy post about how he drilled them out with the barrel still in it, punched the rivets through into the cavity between the trunion and barrel and then used a small chisel to break the rivet tail up into pieces small enough that they would fall out the hole. It is work either way, but I did not feel like trying to chop up the bits of rivet in the hole, sounded like more trouble than it was worth. If you are going to pull the barrel you have the option of doing a nice rivet job while you have the barrel out or if you are going to screw it together it is easier to tap it when you have the barrel out as well.
 
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