Barrel mounting issue

[jhyan]

I was mounting a new barrel (.223 wylde 18" melonite 1:7 from PSA) in an Aero Precision Enhanced upper. I dry fit it, and everything lined up fine. I greased the barrel nut threads, but neglected to grease the barrel extension where it mates to the upper receiver.

I torqued the barrel nut to 35 foot pounds and released it twice, then torqued it to 40 foot pounds. I then went to install my gas block and gas tube and realized the barrel was off. It rotated about 5-10 degrees, making the gas port not line up, as well as the feed ramps. I went to pull it apart to see what was wrong, and after taking off the barrel nut, I can't separate the barrel from the receiver.

Anyone have an idea why 1) it twisted in the receiver and 2) why I can't get it to untwist/pull out (guessing it's the lack of lube... it's in the freezer right now to shrink the barrel, then I will heat the receiver with a hair dryer and try to separate).

[ztrack157]

Did the extension pin destroy your upper or stay in place?

[jhyan]

Can't see the pin at this point

[scamp62]

"can't see the pin" ???????.........really !!!!!
very weird !....pic's please !
p.s. did the barrel have a pin ????

[PaperPuncher]

Can you post some pictures of the receiver (inside and out), barrel extension, barrel, and where the barrel mates to the upper?

[ar15barrels]

I was mounting a new barrel (.223 wylde 18" melonite 1:7 from PSA) in an Aero Precision Enhanced upper. I dry fit it, and everything lined up fine. I greased the barrel nut threads, but neglected to grease the barrel extension where it mates to the upper receiver.

I torqued the barrel nut to 35 foot pounds and released it twice, then torqued it to 40 foot pounds. I then went to install my gas block and gas tube and realized the barrel was off. It rotated about 5-10 degrees, making the gas port not line up, as well as the feed ramps. I went to pull it apart to see what was wrong, and after taking off the barrel nut, I can't separate the barrel from the receiver.

Anyone have an idea why 1) it twisted in the receiver and 2) why I can't get it to untwist/pull out (guessing it's the lack of lube... it's in the freezer right now to shrink the barrel, then I will heat the receiver with a hair dryer and try to separate).

What fixture were you using to hold the receiver while you torqued the barrel nut?

[jhyan]

I was using a upper receiver block held in a bench vise. The block is like this one...

http://www.ebay.com/itm/Block-for-308-223-5-56-For-Rifle-Gun-Repair-Smithing-Tool-Upper-Receiver-Vise/381974547550?_trksid=p2045573.c100505.m3226&_trkparms=aid%3D555014%26algo%3DPL.DEFAULT%26ao%3D1%26asc%3D41376%26meid%3Dabbc05ef1c1a4102b5d59f786870aa3c%26pid%3D100505%26rk%3D1%26rkt%3D1%26

[PaperPuncher]

If you have a strap wrench you might want to see if you can spin the barrel back a bit then pull it out. It looks like you spun that barrel pin through the notch in the upper. With that upper, not sure how you are going to see the pin or if there is any irreparable damage. I would imagine the barrel could be salvaged. Also, get a proper barrel vise.

[UclaPeon44]

didn't know one can do that, being that the barrel has a guide pin to seat the barrel on straight. urgh!

[ar15barrels]

Either your barrel index pin was MISSING, your barrel extension was machined wrong or your receiver was machined wrong or you somehow broke the barrel indexing pin.
Those are the only possible ways to get that much misalignment.
Is the gas port properly aligned at 12:00?

[jhyan]

Also, get a proper barrel vise.

Not familiar with that. Point me toward a quality one?

[jhyan]

Either your barrel index pin was MISSING, your barrel extension was machined wrong or your receiver was machined wrong or you somehow broke the barrel indexing pin.
Those are the only possible ways to get that much misalignment.
Is the gas port properly aligned at 12:00?

The gas port is not properly aligned... it is off the same as the feed ramps.

I figure I either seated the pin correctly, and it spun to the side deforming the soft aluminum... or I was a total idiot and didn't have the pin seated correctly and mashed the pin in to the front of the receiver just to the side of the pin slot.

[jhyan]

Just pulled it out of the freezer and heated the receiver, then tried pushing it forward with a wooden dowel. No go, it's really really in there.

[ar15barrels]

Not familiar with that. Point me toward a quality one?

Don't use a barrel vise with your receiver.
You are doing it right by holding the receiver in blocks to tighten the internal barrel nut.

[ar15barrels]

Just pulled it out of the freezer and heated the receiver, then tried pushing it forward with a wooden dowel. No go, it's really really in there.

You need a 1/2" socket extension about 6" long and whatever size deep socket will slip into your receiver's 1" bore.
Rest the face of the receiver on the edge of the workbench and tap on the socket extension to knock the barrel out.
You will want a 3rd hand to hold the barrel or it will get away from you and end up hitting your foot or the floor when it pops free.