What kind of tool does the flash hider nut take? It is round with two 1/8" holes 180 degrees apart. Looks like it takes a small spanner, or maybe a plier-type tool with a pin in each jaw. Already tried tapping it around with a punch.
I knew it would take a pin spanner (edge, not face) but was just wondering if there was a specific tool that others may have used. Anyway, the thing has a soft steel washer between the jam nut and brake. After indexing, the armorer stakes the washer into at least two of the notches (one on each part) to lock the assembly. I un-staked it but still couldn't break it loose, so now I'm letting it have some Kroil in the interface, thinking maybe there is some corrosion holding it together. I'm determined to get the last part of the grenade launcher off the barrel to reduce front-end weight. This rifle has too much finish wear to be a collector, so I'm pretty much going to do what I want with it. Here's a good picture of the area showing the washer staked in the lower notch. I'm assuming the armorer would use two pin spnners, one on the nut and the other in a vent hole on the brake. You can also see one notch on the lower front - this indexes the bayonet and is not repeated on the upper front so it's of little use. I might be able to snag it with a spanner but it's doubtful because of the rounded front.
These would probably work: BROWNELLS
Thanks - I think you're right.
Got it. I went back and improved the de-staking of the lock washer and let the 'Sili-Kroil' work for a few days. This time it came off easily and I slipped the grenade-locating ring off the barrel and put the flash hider back on. The FH and lock nut have some plier marks (Vise-Grips) but I'll clean those up and refinish today.
BTW, I know many of you use Kano Lab's 'Kroil', but try their 'Sili-Kroil' - it's even better as a penetrant.