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Posted: 12/2/2009 4:50:27 PM EDT
| I have an 86 romanian kit i'm building. It's my first kit and I expected a few speed bumps along the way but this damn barrel pin is freaking crazy. tried the "beat it out with a hammer" method, didnt work. Then tried the 20 ton press. broke my punch and kinda mushroomed my pin out a bit. we were at my buddys machine shop so we had acces to a mill so we took the surface of the pin off flush to the trunion. he then bored into the pin a 3/16th hole and we shoved a dowel pin in and headed back to the press. after a good amount of pressure we snapped the dowel pin. I have it soaking in penetrating oil right now and we will try again tomorrow i guess. any other advice? I havent even looked for a new pin yet, hopefully they are attainable (or i guess it will have to be custom). We are building a rivet smasher on the side, I'll try and post some pics of what we end up with...if we get that far.... haha. Any help appreciated! |
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i have the SAME thing with my SAR's front FSB pin. I am trying to install a brake and I have to remove it to install the detent and it WON'T move. I have broken punches and my next step os my dads press but i'm prolly gonna just snap another few punches....
same thing with my parts kit barrel. dammit.... |
| I've had some sticky ones, and I have heard the '86s were a bit harder than most. What I did was to make a starter punch out of a 1" long grade 5 bolt and ground down the end to be slighly smaller than the pin. That and a 20 ton press and cranking on it pretty hard gave me a nice loud "bang", which is the pin breaking free. After that switch over to a longer punch to push it out the rest of the way. The pin will probably be galled up a bit when you get it out, but can probably be salvaged. AK Builder has replacement pins if yours ends up too messed up. |
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If you have a mill, stop wasting time with the press!
Center and drill the pin out, the original barrel pin is a few thousands over 7mm from being driven in, so get a 7mm drill, and some smaller (can be metric or us) and work up to the 7mm (it may break free around a 5.5mm or 6.25mm drill, but still get the 7mm). You can a new pin from CNC Warrior ( http://www.cncwarrior.com/comersus/store/comersus_viewItem.asp?idProduct=6 ) for $5. |
| Mine did just what "The Mad Axeman" said. I started out with a couple of smaller bits and worked up in sizes and it was off center too, which worried me, but then I got it before it was where I was going to mess it up. I used a little heat (torch) too. I don't know if using the torch was good for it , but I know it helped mine break free finally. I broke a bit in it also but was able to get it out. I thought I was going to look like a skin head by the time I got it free. |
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no one ever had to drill them out in the past. a 20 ton press is more than enough, to press teh pin out with the correct jigs
you gotta have the right set up. either buy the right tools or make them. http://www.theakforum.net/phpBB2/viewtopic.php?t=53360&postdays=0&postorder=asc&start=25 about in the middle of the page will show a homemade set up that pess the shit out of the pin,no problem |
| well to make a long story short- the pin is out! drilled through the pin, got as close as comfortable to the sight block (5mm drill then to one slightly bigger- dont remember the size) and it still wouldnt budge. there wasnt a whole lot to push on by that point though, the pin was pretty mangled... with the remnants of the pin still in the hole we decided to press the barrel out. whatever was in the hole was easily sheered off and cleaned out after the barrel was removed. what a PITA! Kinda fun though... After this build I may look into the "proper" jigs and what-not, I can totally see where correct tools would be helpful. Thanks for all of your replies! Next step is to hopefully remove the rear trunion and finish getting rivets out of the trigger guard, then I think i'm pretty close to throwing it back together... |
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Congrats on getting the pin out. I thought I'd post a little tip for anyone who searches for barrel pin removal.
Just yesterday I removed the barrel pin from an '86 Romy G. It takes a bit of work but here is how to do it: Put the trunnion in a 5"+ vise. Take a piece of soft metal (brass/aluminum/etc) drill a 1/2" or so hole in it. Use that piece of metal as a buffer plate between the anvil side jaw and the trunnion, position the hole so that the barrel pin would go through it. Then cut down a cap head screw that's diameter is slightly smaller than the barrel pin. Cut it down so that it is about 3/4" long. Put that screw on the other vise jaw and use it as a punch while you clamp down on the trunnion. When I did that the first time, I broke my vise when I put too much pressure while turning the handle. The trick is to tighten the vise down very very tight, but not so much that you break it. Then whack the $%#^ out of the vise with a BFH (Big... Hammer). Don't be shy hit it hard. Then twist the handle again until it's tight. Rinse, repeat. You must hit it hard and with a purpose, but the shock from the hammer hits will eventually get the pin moving. Once it starts moving, the rest is cake. This tip is straight from ashhoe. Thank him for making barrel removal a little bit easier. -Jim |
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