S&j barrel extension came lose
- Thread starter WAREWOLF
- Start date
for accualy having to do it
The actual barrel extension should be 85 ft/lbs. And there should be no way that it 'just came off'. The problem with just tightening it back up is that the gas port may not be line up properly if it was drilled without the extension being tight.
Not to doubt you.......but it was the barrel extension that came loose? Or just that the barrel nut is not tight enough and the the barrel is moving inside the receiver?
If it is in fact loose, you should send it back and request a new barrel.
Not to doubt you.......but it was the barrel extension that came loose? Or just that the barrel nut is not tight enough and the the barrel is moving inside the receiver?
If it is in fact loose, you should send it back and request a new barrel.
it is the extension that came loose
i e-mailed S&J hardware and Simon there is going to take care of it. they are paying my shipping and are going to re-index the and torck the extension or send me a new barrel.
great service from S&J Hardware
- Location
- East ontario
No problem
sorry for the issue, we have a a few items that we have slipped on the QC, it has been a small issue that we have had out of the 1000+ units we have sold .
Again sorry for the issue, will be taken care of asap.
BBB
FWIW, this should not readily happen. The locator pin i nthe extension is supposed to be drileld deep enough that the seated pin prevents unscrewing, but once in a while the pin isn;t deep anough and rides the threadform up enough that it will turn when removing a barrel nut or flash hider.
It's a QA/QC issue that the manufacturer or dealer should deal with/correct/warranty.
You see this more frequently on barrels where there finish is applied AFTER the barrel extension is attached. The highest-end bbl makers apply the finish to both parts separately then mate and pin them, on these bbl's the pin will usually have a different finish (or not finish) than the barre land extension.
It's also common on nitr-carburized barrels if the NC coating is done with the extension installed. Thermal expansion is different betwene the extension and barrel threads owing to differing material spec and geometry, causing the extension to loosen a little and the pin may not be enough to hold the assembly in position.
It's a QA/QC issue that the manufacturer or dealer should deal with/correct/warranty.
You see this more frequently on barrels where there finish is applied AFTER the barrel extension is attached. The highest-end bbl makers apply the finish to both parts separately then mate and pin them, on these bbl's the pin will usually have a different finish (or not finish) than the barre land extension.
It's also common on nitr-carburized barrels if the NC coating is done with the extension installed. Thermal expansion is different betwene the extension and barrel threads owing to differing material spec and geometry, causing the extension to loosen a little and the pin may not be enough to hold the assembly in position.
While some/many manufacturers will/do drill into the threads and then use the pin as a locking device, the original purpose of the pin was/is solely for barrel alignment.
The barrel should be clamped in a barrel vice to attach/remove the flash hider and while the flash hider requires less torque than the barrel extension, the barrel extension/receiver should not be relied upon to resist that torque.
THIS!
This thread is the first I've ever heard that the pin is supposed to lock the extension on. None of my drawings indicate this.
Edit: IIRC, the barrel extension drawing specifically notes that the pin cannot intrude into the threads.
