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Posted: 12/25/2007 8:43:21 AM EDT
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I recently rescued an A3 upper receiver from a friend (along with a mucked up, but very serviceable 14.5" fluted Bushmaster barrel-presently at ADCO for TLC). He uses the clamping style receiver blocks and I think he may have actually clamped down too hard. Out of 11 BCGs on hand, none of them will freely move in the upper. You can press the carrier in and they will go all the way but there is resistance, some more some less. I have determined that the resistance or binding is on the carrier key, mid way into the upper. Now the really question........Do I try to grind down the sides of a carrier key or attempt at making wedges (out of hard wood) to open up the channel of the receiver? |
The fix was posted some months back. I did what was posted. Lock the upper in a padded vice.(Just your rail or carrying handle) I used two 100 mile hour taped pry bars (small auto type) to open the receiver up. (The op used something else) Put the bars in the charging handle channel (by the bottom of the receiver) and opened her up. The receiver was likely crushed because the block(inside receiver) was not used with the clam style tool. The receiver will spring back. Or I'll give you $1 for it  Try the search, the OP's post was better then mine. But the next week I had to do what he said. An upper I bought on EE was F'd up. Now it has 3,000+ rounds on it. Good luck. ATB |
No, the problem is definitely with the receiver. The receiver is stripped. No gas tube to bind on and no bolt in the carriers to cause headspace issues. I could buy another receiver for $95, however if a $10 repair will do, why not give it a go. Need to search out that archived thread. |
Clam shell "crushed" the receiver. I would bet without seeing it, the squeeze is in front of the ejection port. You need to spring it back out. Like if you squeeze a 1911 slide to much. Then you spread it. The fix is easy, But I would do much better showing how then writing it. He needs to find the OP. I saw it some time after June 07. Good luck! ATB |
Exactly right where the carrier key begins to bind! Good call. To make the receiver a bit more willing, I figure that I should heat it up first in the oven. Pound the wedge down through the back of the receiver and let it cool with the wedge in place. |
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Exactly right where the carrier key begins to bind! Good call. To make the receiver a bit more willing, I figure that I should heat it up first in the oven. Pound the wedge down through the back of the receiver and let it cool with the wedge in place. Don't heat her up or use a wedge. A wedge would be the last choice as it can open her up to much. IM or e-mail me. Send me the upper and I'll try the fix. Then I'll send her back. ATB |
Binding may not be the best word for it, but I have tried 11 bolt carriers (without the bolt and the upper is stripped) and the resistance all way begins in the same place. Definitely the upper as there is nothing else to cause the resistance on the carriers. For gits and shiggles I removed the carrier key from one of the carrier that was not staked into place and the carrier moved freely. |
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