Local gunsmith removed the barrel nut from my Colt, which was under about 80 foot pounds of torque, and this is the result. Will this not throw my FSB off? If so, what’s the fix for a guy who takes an upper to a Gunsmith to remove a barrel but?
AR barrel extension index pin
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GunnyUSMC
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Did he mess up the upper too?
mcb
Member
Tell him to use a reaction rod with a lug for the charging handle slot next time. That would not have happened with the proper support given by that type of reaction rod.
Is the index pin bent or the hole distorted, or both?
Is the index pin bent or the hole distorted, or both?
MachIVshooter
Member
mcb
Member
I got the impression from the OP this was the result of removing the barrel not installing. Either way a lugged reaction rod would have prevented that type of damage going on or off.
Seriously? Thinking about it I did have to adjust a good bit of windage in both the BUIS and the AimPoint. I’ve read about removing the pin with side-cutters. Gave it one try. Failed and quit. I Didn’t want to make things worse. As in more expensive when I find another gunsmith. This guy made a mess of the FSB surrounding the taper pins.
Blue68f100
Member
If you can remove the pin and replace it with a new one (needs to be straight), I've had to drill one out. The pin is normally long enough to get into the threads on barrel. I've removed a couple over the years they can be a pita. The problem you will have is the gas port will be off at an angle. You can always remove 1 thread and get the index to align on the gas port, then recut the chamber. May not be worth the expense of a new barrel.
How bad did he mess the upper up? With a pin tilted it would not fit in the slot, without excessive force.
Normally these barrel extension nuts are torqued to 80-120 ft/lbs. Some use loctite to secure them in place, so heat would be required to make it release. The torquing removes about 0.0015" of head spacing. This is normally allowed for during the machining process.
How bad did he mess the upper up? With a pin tilted it would not fit in the slot, without excessive force.
Normally these barrel extension nuts are torqued to 80-120 ft/lbs. Some use loctite to secure them in place, so heat would be required to make it release. The torquing removes about 0.0015" of head spacing. This is normally allowed for during the machining process.
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rbernie
Contributing Member
Judging by the direction in which the pin was bent, that was my reaction as well.
I tried grabbing the pin with side cutters and levering it out. It's solid and didn't budge. No local gunsmiths in my area but there is an equipment rebuild shop nearby I'm gonna stop and talk to. If not I'll either ship or buy another barrel and have this one as backup after getting it fixed. Sometimes living in the sticks has it's drawbacks.
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GunnyUSMC
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The price of barrel have come down a lot in the last two years. About eight years ago Mossburg was the major manufacture of AR barrels in the US. They made them for just about everyone. Today there are several manufacturers of AR barrels. Thank God for CNC. 
Depending on what type of use you have for the rifle there is a wide price range of barrels on the market and you can often find them on sale.
Of all the ARs I have built I have only gotten one bad barrel. It was a 300 BLK Out barrel that I got in a kit from Delta Team Tactical. No matter what I did, I just couldn't get the gun to run. The Tec support at Delta Team were outstanding. After a few phone calls and trying different things, even drilling the gas port larger, they asked me to send the upper back. About two weeks later I got the upper back with a new barrel, handrail, gas tube and gas block. When I called to thank them they said that the old barrel had a bad chamber and they replaced the handrail because it had gotten scratched when I was working on it..
I did ask how they were able to sell barrels at such great prices, I was told that they buy them by the pallet. I've bought several barrels from them and like the XX-Tream brand barrels they sale.
Depending on what type of use you have for the rifle there is a wide price range of barrels on the market and you can often find them on sale.
Of all the ARs I have built I have only gotten one bad barrel. It was a 300 BLK Out barrel that I got in a kit from Delta Team Tactical. No matter what I did, I just couldn't get the gun to run. The Tec support at Delta Team were outstanding. After a few phone calls and trying different things, even drilling the gas port larger, they asked me to send the upper back. About two weeks later I got the upper back with a new barrel, handrail, gas tube and gas block. When I called to thank them they said that the old barrel had a bad chamber and they replaced the handrail because it had gotten scratched when I was working on it..
I did ask how they were able to sell barrels at such great prices, I was told that they buy them by the pallet. I've bought several barrels from them and like the XX-Tream brand barrels they sale.
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