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Posted: 10/5/2011 9:03:23 AM EDT
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Hey everyone, I need help with an oly arms k16 upper. To start by addressing some comments I know will come up. Yes the gun runs great, never had any problems with it. Yes it shoots accurately, and I have taken it past 100 yards.
Here are my 2 problems... 1. I cannot get the roll pin for the gas tube out of the block. What size punch do I need, or is there a cheap way to remove it? 2. This upper has the tube hand guard which I cant get off. I am using a slip wrench but I guess it is on tighter than I can force. Anyone know a solution for removing the hand guard? Oly wants to charge me $50/hr. to do the work. If I have to have this sent out for these two problems to be fixed, does anyone know of a place where it can be done cheaply? |
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From the stickied tutorial here in BIY:
" A small punch to knock out the gas tube roll pin. I used a 1/16” drill bit because I did not have a punch that small." Assemble_your_own_LOWER__UPPER__FREE_FLOAT__TRIGGER__GAS_BLOCK___Step_by_step_instructions As far as the tube, I recommend heat. Heatgun, hair dryer, whatever it takes to heat up the tube in the area of the barrel nut. |
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Quoted:
From the stickied tutorial here in BIY: " A small punch to knock out the gas tube roll pin. I used a 1/16” drill bit because I did not have a punch that small." Assemble_your_own_LOWER__UPPER__FREE_FLOAT__TRIGGER__GAS_BLOCK___Step_by_step_instructions As far as the tube, I recommend heat. Heatgun, hair dryer, whatever it takes to heat up the tube in the area of the barrel nut. Ive managed to break my only two 1/16" drill bits now. The damn pin wont budge. I mean zero movement. Kind of frustrating. Anyone have a video on how to do this? It cant possibly be this hard. |
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Quoted: Quoted: From the stickied tutorial here in BIY: " A small punch to knock out the gas tube roll pin. I used a 1/16” drill bit because I did not have a punch that small." Assemble_your_own_LOWER__UPPER__FREE_FLOAT__TRIGGER__GAS_BLOCK___Step_by_step_instructions As far as the tube, I recommend heat. Heatgun, hair dryer, whatever it takes to heat up the tube in the area of the barrel nut. Ive managed to break my only two 1/16" drill bits now. The damn pin wont budge. I mean zero movement. Kind of frustrating. Anyone have a video on how to do this? It cant possibly be this hard. CLICK Proper tools and all that. |
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Last time I had a problem getting a gas tube roll pin out, it was because the part I was hammering on was not well supported, and the gas block was taking out some of the impact in flex.
Got it down on a cement floor with a brownell's block directly under the roll pin hole, and it hammered out pretty easily. Sorry for the broken drill bits. ETA: You could try hammering from the other side, also, though it should not matter for a gas tube roll-pin. |
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$50/hr is not a bad shop rate.
Make sure the gas block is solidly supported and use the largest punch that will fit the hole. A short punch will not break as easy. Hopefully the pin was not put in with red Loctite. If the tube was installed with red Loctite then you will need a lot of heat. And cleaning out the treads afterward may be an adventure. I certainly would not want to remove the anodizing in the thread area as a person could not see corrosion if it formed under the barrel nut. |
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Quoted:
Is the hole for the roll pin a thru hole or a blind hole ( entrance but no exit )?? You probably have peened over the end of the roll pin by now. May have to drill out the roll pin and replace it. It is a thru hole. I dont want to damage the gas tube by drilling it out. any advise for drilling if I have to? |
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Quoted:
Last time I had a problem getting a gas tube roll pin out, it was because the part I was hammering on was not well supported, and the gas block was taking out some of the impact in flex. Got it down on a cement floor with a brownell's block directly under the roll pin hole, and it hammered out pretty easily. Sorry for the broken drill bits. ETA: You could try hammering from the other side, also, though it should not matter for a gas tube roll-pin. I have it in a vice on a secure table. I am hitting it level from right to left. I have it sitting in oil so I will try again in the morning. |
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Please follow the link that iNeXile556 graciously posted. Use the PROPER tool, and the roll pin WILL be reusable. If not, spend $5 for the $.90 roll pin. If you are going to continue to work on the AR, you will need tools. Sometimes you can get away with shadetree, but the proper tools help a TON! If you flare the end of this roll pin, you are doing more damage than good to the AR also. WIth the proper tool and rifle block, a couple of taps, and this thing is out.
The tube handguard should take the about 5 minutes to undo unless someone used red Loctite or any "permanent" type of thread lock. This requires heat to get off. If they used the lower torque type thread lockers - That bugger will probably be stiff to get off - So to speak. Do they only charge by the hour? You can easily sink $50-70 in trying tools from stores. The traditional slip wrenches should work, but I have read post after post about what wrenches work and one's that don't. Google this with AR15 in the title and there should be a wrench that will work since the search tool is limited for non-members. Most of the slip wrenches from Walmart, NAPA, etc - Don't seem to work well from what I remember reading. I might be wrong, and it won't be the first time. |
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Hello, I decided to update my thread. I did manage to get the roll pin out, and discovered why it was so difficult to remove. After several solid whacks with a 5/64th punch and a hammer, the pin came out. It was bent in the middle on one side. It chipped one side of the aluminum from my old gas block when it broke free. I do not think this damage was due to my removal techniques.
Anyway, I also got the hand guard off, it just took a strap wrench and a little assistance from my buddy. Blue loctite is all over the threads. I was planning to go to the hardware store to look for another roll pin. I assume the pin is a 5/64th. Is this correct? Also, is it ok to cut a roll pin shorter? The pin from the old block is too wide for my low profile gas block and would stick out on either side. |
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