AR Sponsor
Posted: 12/28/2015 12:43:39 AM EDT
|
I wonder if anyone have experience this before. I looked everywhere on the internet but haven't found anything remotely to what I'm exprencing. Today I was torquing down my flash hider behind a crush washer. I set the torque wrench to 15 ft lbs. I figure it be a quick turn but the flash hider kept rotating and rotating. After about 6-7 rotations, I figure something isn't right. I back out the dpms armor wrench and noted the crush washer was completely deformed. In fact, it's looks to fuse in my flash hider. There is now no way to even budge the muzzle device. I have clamp the entire upper in my magpul bev block and have no success. To remove the muzzle device.
I think what happened was when I clamped the flash hider, the armor wrench made contact with the washer such that both were turning together as I attempted to torque the muzzle device to spec; eventually leading to my current mess of an ar build. Going to the armor tomorrow to hope I didn't just destroy a $350 barrel and a $100 buzzle device. Anyone experience something like that before? |
|
Any chance you can post a pic? Is this a factory build barrel with a permanently attached flash hider? If so, then it might have been pinned & soldered, which means that it would have to be machined off. If it's a threaded barrel where you were installing a flash hider, and now nothing will come off or on no matter how much you spin things, it sounds like it may be time to get it in the hands of a gunsmith in case you have stripped something.
To install a flash hider, comp or muzzle brake using a crush washer, place the crush washer on the barrel, then put the flash hider on the barrel and tighten it down with your fingers only. Once you have the flash hider finger tight, then use a wrench to tighten the flash hider more until you obtain the desired indexing that you wish. When using a crush washer, put the crush washer on the barrel so that convex part (domed narrow end) is facing that back of the barrel, and the concave (cupped wider end) so that it's toward the muzzle. By placing the crush washer this way, you will see that the flash hider is wider in diameter than the barrel, which will allow you to crush (compress) the washer to obtain the desired indexing of the flash hider or muzzle brake. CY6 Greg Sullivan "Sully" SLR15 Rifles TheDefensiveEdge.com (763) 712-0123 |
|
Ditto with sully that the crush washer is used to first tighten the device by hand until it finger tight, them the muzzle device is only spun enough to to index the Device correctly with less than a full rotation of the device (what room the crush washer has before it will be flattened out).
The fact that you spun the Muzzle device 7 to 8 winds more after finger tightened, tells me that either the torque wrench was not calibrated correctly to begin with, or that you did not stop torquing on the wrench once the wrench clicked; ending with the threads on the barrel over torqued to distort them and the last inch of bore, and other stripping the threads of the barre/device. Further more, with a crush washer, a torque wrench is not needed, since again, once you have the muzzle device hand tight against the crush washer, all is needed is a standard wrench since the Muzzle device is spun less than a full turn to just index the muzzle device instead. Bluntly, you can bank that the threaded section of the barrel is cooked, and with luck, this barrel is long enough that the damage threaded section of the barrel can be cut off, with the barrel re-crowned/re-threaded back on still good bore, and depending on the muzzle device, if it was the barrel threads that stripped and not the device threads instead, it might be salvageable with it threads just cleaned up. |
| If it's timed how it is now i think you should just leave it be, doesn't sound like it's going to back out on you. Something else you can do to avoid having ADCO snip the barrel is get the muzzle device pinned/welded as long as its indexed correctly, and count this as a lesson learned. 7-8 turns past hand tight is 6-7 turns too many. |
|
Quoted:
Ditto with sully that the crush washer is used to first tighten the device by hand until it finger tight, them the muzzle device is only spun enough to to index the Device correctly with less than a full rotation of the device (what room the crush washer has before it will be flattened out). The fact that you spun the Muzzle device 7 to 8 winds more after finger tightened, tells me that either the torque wrench was not calibrated correctly to begin with, or that you did not stop torquing on the wrench once the wrench clicked; ending with the threads on the barrel over torqued to distort them and the last inch of bore, and other stripping the threads of the barre/device. Further more, with a crush washer, a torque wrench is not needed, since again, once you have the muzzle device hand tight against the crush washer, all is needed is a standard wrench since the Muzzle device is spun less than a full turn to just index the muzzle device instead. Bluntly, you can bank that the threaded section of the barrel is cooked, and with luck, this barrel is long enough that the damage threaded section of the barrel can be cut off, with the barrel re-crowned/re-threaded back on still good bore, and depending on the muzzle device, if it was the barrel threads that stripped and not the device threads instead, it might be salvageable with it threads just cleaned up. Yep, like you said, local gun smith told me I almost completely ripped out the treads. He did his magic and was able to fix the mess I did. Also told me for future reference, crush washers does not need to be torqued down. Brought my rifle back today with the muzzle pinned. Thanks everyone for the input. |
AR Sponsor
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.