Removing a rifle receiver extension: it's really stuck

[Amicus]

OK, this is self-inflicted because I installed it, but I can only assume I must have overtorqued it about 7 years ago.

I mounted the lower receiver using a mag well vise block and attempted to remove the receiver extension.

I have managed to destroy/mangle/round off the rifle receiver extension wrench flats using: military wrench extension, Hammerhead (with 18" cheater), RRA receiver tool, and two crappy armorers wrenches. In frustration, I also used a crescent wrench when I had tried everything else.

The receiver extension is a Colt. I installed it by cleaning the threads and using grease; no loctite or other adhesive. I am pretty attentive to torque values and (presumably) torqued it to 37 +/- 2 ft lbs.

At this point I became concerned that the mag well block might cause the lower to bend or break under the force of the torque I was applying.

Finally, out of frustration, I clamped a vise on to what is left of the wrench flats and attempted to turn the lower receiver using the grip. No luck, the vise deformed the flats and the receiver extension slipped from the vise. I tried this three more times, same result.

Now, I am willing to destroy the receiver extension to preserve the lower receiver. Should I crush the tube in a vise and then turn the lower? If so, is it better to crush the receiver extension near the rear or near the front?

Or, anything other ideas?

[CRAMBONE]

You are sure you didn't use loketite? I would say if you do what you are describing the R.E. will probably just shear in half.

[Amicus]

You did remove the buffer retainer pin and spring? You are sure you didn't use loketite? I would say if you do what you are describing the R.E. will probably just shear in half.

The receiver extension currently holds the buffer retainer pin and spring. I can not remove them until I can unscrew the receiver extension (or, cut it away from the pin).

I am sure I did not use loctite. I never have.

[Kain]

OP, what grease did you use? I am spit balling here after a few drinks after a long day, but I am wondering if after 7 years that the grease could have dried out or solidified somehow to create an adhesive type bond. From the sounds of things the RE is probably going to be toast anyway, but I'd would consider heating the RE/lower connection point up with a torch to see if that helps unthread. Would have personally have done that a while back before jacking up the nut and everything, but point remains.

P.S.
When you are saying rifle is this the RE for a A1/A2 rifle stock assembly or a carbine RE with castle nut, ect?

[Clint]

Try cross drilling the extension near the end with the flats.

Drill 1/4" diameter and then insert a 1/4" pin or drill rod to form a T handle.

[MistWolf]

Soak the threads in something like Mouse Milk for a couple of days. Heat the area with a heat gun (Do NOT use an open flame) or heat it in the oven at low temperatures (250°) for no more than 15 minutes (to prevent annealing the aluminum). If you need to sacrifice the RE, a hole can be drilled through the tube near the receiver and a long round rod or a screw driver with a long round shaft put through the holes (drill completely through both sides of the tube) and used to break the RE loose. Of course, you'll need to use a lower receiver block to hold the lower safely in place.

If heating doesn't work, put the lower in the freezer over night. Just don't heat the parts right after pulling them out of the freezer. I don't know that it will hurt anything, but I'm not certain it won't

[Amicus]

OP, what grease did you use? I am spit balling here after a few drinks after a long day, but I am wondering if after 7 years that the grease could have dried out or solidified somehow to create an adhesive type bond. From the sounds of things the RE is probably going to be toast anyway, but I'd would consider heating the RE/lower connection point up with a torch to see if that helps unthread. Would have personally have done that a while back before jacking up the nut and everything, but point remains.

P.S.
When you are saying rifle is this the RE for a A1/A2 rifle stock assembly or a carbine RE with castle nut, ect?

You're right about the torch. I used a heat gun instead, but I wasn't anticipating much trouble because I knew I had not used a known adhesive.

The grease was (probably): Bostik Never-Seez Anti-seize and lubricating compound with molybdenum disulfide.

This is a rifle receiver extension (with a rifle buffer and spring); no castle nuts or end plates involved.

[MistWolf]

No torch! An open flame can cause embrittlement of the aluminum

[Amicus]

Soak the threads in something like Mouse Milk for a couple of days. Heat the area with a heat gun (Do NOT use an open flame) or heat it in the oven at low temperatures (250°) for no more than 15 minutes (to prevent annealing the aluminum). If you need to sacrifice the RE, a hole can be drilled through the tube near the receiver and a long round rod or a screw driver with a long round shaft put through the holes (drill completely through both sides of the tube) and used to break the RE loose. Of course, you'll need to use a lower receiver block to hold the lower safely in place.

If heating doesn't work, put the lower in the freezer over night. Just don't heat the parts right after pulling them out of the freezer. I don't know that it will hurt anything, but I'm not certain it won't

I put Kroil on it this afternoon and put it in the freezer tonight. I am about at the end of my tricks though.

Thanks for the suggestion about the drilling holes all the way through the receiver (i.e., on both sides). I think I have read about that method, but had forgotten it completely. That will be my next option.

[Amicus]

No torch! An open flame can cause embrittlement of the aluminum

Thanks. Didn't know that.