Loose barrel extension on melonite treated barrel...

[pathfinderheli]

I have a BCM SS410 18" Rifle Gas that was dimpled and then melonited. I was confirming the torque (20lbs) / rocksetting the brake on it and the barrel rotated. I figure I had sheared the indexing pin or broke the upper receiver but noticed that the extension was not rotating....

Pulled the barrel off the build (not happy as this was a URX 3.1) and noted that in fact the barrel extension has come loose.

Is there a way to fix this i.e. who can I send this to for fixing? I dumped a ton of money in this barrel so if it can be saved that would be awesome....


EDIT:
pic removed as it bears no contribution to the issue.

[Iraqgunz]

You should be contacting BCM as per the site rules.

[Iraqgunz]

Re-opened as I may have misunderstood this. Was this something done aftermarket? If so, you are screwed because you can't simply retorque a barrel extension into place. That's because the gas port is drilled after the barrel extension is torqued to the barrel.

[Koshinn]

It's been cautioned that meloniting a barrel after the extension is installed can loosen it due to the high heat required for meloniting and the different materials...

Can't he get someone like ADCO to weld the port and drill a new one?

[pathfinderheli]

Sorry if I wasn't clear on what the issue was. Dimpling and Meloniting was done aftermarket by two separate companies. As the poster above stated, after some research, it does look like this can be a common problem with Meloniting a barrel.

[Robb Jensen]

I had one come lose after meloniting. I just carefully Rocksett the extension back on being very careful to get it where it was and after that cured (after 24hrs) installed a new index pin. Put the pin in last because I used the mark the original pin left in the threads as a guide. Then when I torqued the barrel nut I DID NOT use a Geissele Reaction Rod I used an upper receiver block and then triple checked headspace with a NOGO, FIELD and Colt FIELD II gauge, it worked out fine.

[constructor]

I have a BCM SS410 18" Rifle Gas that was dimpled and then melonited. I was confirming the torque (20lbs) / rocksetting the brake on it and the barrel rotated. I figure I had sheared the indexing pin or broke the upper receiver but noticed that the extension was not rotating....

Pulled the barrel off the build (not happy as this was a URX 3.1) and noted that in fact the barrel extension has come loose.

Is there a way to fix this i.e. who can I send this to for fixing? I dumped a ton of money in this barrel so if it can be saved that would be awesome....


EDIT:
pic removed as it bears no contribution to the issue.

The only real way to do it right is for someone that has a pile...like 100 barrel extensions. Install them torqued correctly until 1 lines up perfectly or is very close to aligning on the before TDC side. Then turn .001 -.002 off the front of the extension so it will turn a little further to align at the required torque.
I fear all these new companies starting to do Melonite barrels will have these issues unless they torque the extensions after treatment and then drill the gas port and dimple. One company that does Melonite treatment is advising people to drill the alignment pin hole deeper and use a longer pin...That will not work long. The extension is not torqued tight, it will loosen and the barrel will wobble in it. Accuracy will go to crap and all the pin does is hold it loose.

[Toecheese]

This doesn't sound good at all. Not sure about saving it!

[Joe Mamma]

The company that did the meloniting/nitriding should step up and resolve this for you. But I would probably try to fix it myself. Loosening barrel extensions while meloniting is a fairly common problem, although the companies that do it say it rarely or never happens. This is why I only get my melonite barrels from companies that tighten the barrel extension and drill the gas port after meloniting/ntriding.

pathfinderheli, Rocksett might not be the best thing to use. I have limited experience with Rocksett. But what you want is obviously very high strength, very high temperature resistance, and good chemical/solvent compatibility. You may want to use one of the (numerous) Loctite products. The people at Loctite have always been very knowledgeable and helpful about product selection when I called them. Since you say this was an expensive build, I would probably put a lot of time into picking the best thread locking product.

Also, checking the headspace should not be necessary if it was headspaced properly to begin with. But it doesn't hurt to check it after you have it assembled again like Robb Jensen did.

Good luck with it, and keep us updated if it's not too much trouble.

Joe Mamma

[markm]

This doesn't sound good at all. Not sure about saving it!

No doubt. I wouldn't want to run this gun. I certainly wouldn't want to give the fukktards who wrecked it a chance to "fix" it.

This is the risk of these aftermarket RETARDS jumping in with the latest whizbang nonsense without having a full grasp of what the fukk they are doing.

They SHOULD pay for the replacement.