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Posted: 2/25/2005 7:50:57 PM EDT
| Today I bought a 12-ton hydraulic press to use on a couple of AMD-65 kits that I want to build-up. For the past few hours I've been trying to press out the barrel pin on the front trunnion in order to remove the barrel. It won't budge. I've had it soaking in Break Free and PB Blaster most of the afternoon and it still won't move. Any suggestions? What would be a good tool to use to press out the pin? I've tried using the shank of a bolt and broke two of them. Then I tried a small punch just slightly smaller than the pin and broke two of those. Then I tried cutting down the shank of a drill bit. Again, I broke two of them. I've tried pressing from both sides and can get no more movement than pressing the pin flat against the trunnion. Any suggestions will be most appreaciated. |
| I made an adapter to go on the headof the ram of my press that accepts an air hammer chisel bit. The bit is turned in the lathe to .250 diameter about 1 inch long. You'll have to use a carbide cutter as the bit is quite hard. I've pressed out several AMD65 barrel pins with it. No problem. You'll have to make some sort of support for the trunion so it's well supported level. |
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Had the same problem. Busted a vise on this pin on an AMD. I took it into the machine shop at work the next day and the guys there used an air hammer. He chucked the trunnion in a vise and applied the air hammer equipped with a flat faced punch. The hammer hit it with 2000-3000 Blows per minute and the pin budged and then came out so hard and fast it flew across the room and put a dent in the wood door of the shop. We then turn the trunnion and usd a bigger hammer faced punch in the air hammer and round bar stock against the breech to drive the barrel out. After a few hits I noticed we were marring the breech so I put a nickel behind the breech and went at it again till it came out. Ruined the nickel but it was relatively cheap insurance against marring the breech. So...I now own an air hammer. Around $50 bucks at Sears. Or if you don't own a compressor $300 for Compressor and 3 tools (including an Air Hammer) Cheers |
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I use a hardened screw driver hex bit to start the pin moving. But be sure to wrap a cloth around it case it slips or shatters. Been doing it this way without any problems. http://www.picyard.com/main/data/500/118mvc-766xtrimed.jpg Also, make sure you support the barrel, front trunnion and rear sight block when you try to remove the pin. |
We knocked two AMD 65 barrel pins out with just a punch and hammer. Get some Kroil and hit the pin and barrel with it, let it sit for a day or two. Put it on a solid floor, like concrete, with a piece of carpet under it. Get the pin started out - it should take just two or three hits with a 2 lb shop hammer and a 1/4" punch. After the pin is started out, lay the barrel/trunnion on a 2x4 with the pin centered over a hole in the 2x4. It'll come out with just two or three more hits.
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Yeah, whack that barrel pin like a bitch! Show her who's boss...... Ooops gotta go the wife came in.....
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One thing I should have mentioned - DO NOT HOLD THE PUNCH WITH YOUR HAND!. We used a pair of Channellocks to hold the pin while whacking it with the 2 lb shop hammer. Being assuccessful as we were, I'd like to say I hit like I live  but that wasn't the reason they came out so easily. Kroil is a great penetrating oil and will actually defiy gravity to "crawl" up threads.I originally thought it was going to be impossible to break them loose but the Kroil worked wonderfully! |
| Thanks for all the advice. The barrel pin on one of the kits finally gave up the ghost late last night and surrendered to the 12-ton press. The other is still soaking in PB Blaster until I can get my hands on some kroil. It's just insane how tight these pins really are! I hope the barrels aren't this stubborn. |
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Well here's the story: I ground an old 1/4" tap so that the shank was all that was left for a pressing pin. Set up the 12 ton to press out the AMD barrel pin and proceeded to apply pressure. At some point in the press, the whole thing kinda just went off with a loud bang and the barrel, press plate, and pressing pin popped off the press. I still haven't found the pressing pin but the barrel and press plate landed about two feet away. I guess I should be glad that it didn't decide to pop my way as I could have had the pressing pin embedded in my chest. Oh, the wife had popped her head into the garage and asked if everything was ok. She had heard the pop from the house over the TV. ps. If someone in Houston has had success in getting these %$#*!! barrel pins out of the AMDs and would like to make a few bucks, you have a customer here. These things are starting to scare me! |
| After soaking for six days in PB Blaster the barrel pin from the second kit is finally out, but not without the aid of Kroil. I finally got my hands on a little of this stuff late this afternoon and after only two hours the barrel pin popped, and I mean POPPED, out. Now, I will admit that the capabilities of the 12-ton press was being stretched but the pin suddenly made two loud pops and broke free. I've never used Kroil before but after wrestling with these AMD-65 barrel pins for the last week I'd have to say that it is almost mandantory to use this stuff unless you have an air hammer or something like that. Thanks to everyone for pointing me down the straight and narrow and suggesting Kroil. I've always thought that PB Blaster was THE penetrating oil, but not anymore. |
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I finally got the barrel pins out of my AMD's. I used a 1/4" rivet punch bought off Ebay - they are stout! put the barrel on the 12 ton, lined up the rivet punch, and popped the barrel pins right out. These worked while the other press pins I had tried shattered or bent. My suggestion is to not bother with trying to fabricate a punch for the pins; just get one of these and knock it out. If the press doesn't get it, you can always put the punch in an air hammer. The rivet punches are standard .401 and fit most common air hammers. Cost for rivet punch on ebay: $3 plus shipping. Satisfaction of getting those &%$!! barrel pins out: priceless! 
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| Wow, you mean I don't have to buy a drill press to drill these out? OK, I have a concrete floor, and a 2lbs shop hammer... wow, thank you!!!h.gif Oh yeah, I have an anvil...hmmm. |
You can get Kroil from Brownell's or buy it from them directly at http://www.kanolabs.com. These are the only two places that I know that carry it. I liked it so much that I bought a whole gallon. I also understand that it's a great bore cleaner. |
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Kroil also will allow you to take your barrel out of the trunnion without a press. We used a vise, nickels against the chamber mouth, and a piece of steel motor shaft to drive ours out. It would not have been as easy if we hadn't hit it with Kroil the day before. I like the aerosol cans better than getting it in liquid form. It seems a little more convenient. Kroil works great for a lot of things. It is a GREAT BORE CLEANER with JB Bore Paste or JB Bore Shine on really accurate rifles. Buidling these rifles is fun. My partner and I have had a good time the last few weeks. We are waiting on two more kits so we can do it again!
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