So I finally brought my can home. First time getting anything that needs a stamp. I go to set up my gen one BRN-180S. Poor thing hasn't seen any range time, just been so busy and the local range is covid crazy, so it's been waiting.

Had a lot of trouble with it, I got one of the ones where the handguard is crazy tight and I've been polishing the barrel shoulder so I could get the handguard on and off.

I pull off the stock flash hider, slide on the surefire warcomp I've been waiting to install.....

Go to reassemble.....

............And the handguard won't clear the rim of the surefire muzzle device. I check it with the surefire socom open (Same as the war comp without the comp) and it won't clear that either.

So.... um...... uh.....

What do I do? Would sending it back for a gen 2 fix this problem?

Can you put on the muzzle device after the hand guard is installed.

That is what I have to do with my cone flash hider.

I have a Stealth suppressor QD muzzle device and I have to I stall/remove the muzzle device whenever I want to remove the handguard. It's because of the way the handguard interface with the barrel nut.

Yes, it's possible to remove the muzzle device every time I take off the handguard I suppose. It's not an idea that especially appeals to me, but that might have to be the way I go.

Surefire directions for this are to clean the threads with acetone, then put on the muzzle device with a torque wrench after using shims to index it, and once you have the rotation right to glue it on with rockset.

https://www.youtube.com/watch?v=CjA9-VbmrXA

So the idea of being so fast and loose with it as to be resetting it every time I clean the rifle gas system might bug their engineers, but you gents figure I can get away with it because of the counter rotating nut on the BRN-180?

I know Gen 2 was just announced last year but I’m interested to see if they open up their handguard interface to allow for us with mounts to remove the handguard w/o spinning off the muzzle device.  Def was something I needed to think about before tossing my ASR on for painting but ultimately a minor inconvenience.

I dunno. I'm very inexperienced with cans, so I'm feel a little out of my depth here. As I was saying above, the surefire guy in the video seems to take the installation of the muzzle device pretty darn seriously.

If you don't clean the threads before installation, what's the worst about that? Is it really that big a thing? I imagine it might not be, as the main reasons I can see to do that are A, perfect alignment, very minor chance of minor misalignment on a dirty surface... and B. the glue will bond better to a clean surface. Now, on the plus side my model is designed for shorter barrels and as such has a little extra space in the middle, (a 30 cal rod just barely passes through) and so I'm much less likely to have a baffle strike, and I did get the alignment test rod so I'm set there.

I know back pressure is a big thing with cans, and I wonder if the rockset is intended in part to prevent gas leakage through the threads, but maybe I'm overthinking it. (I tend to do that.)

My guess is so the Rocksett will bond. It could make a difference on the torque value but I still bet it's about making the glue work.

If the hand guard itself will fit over the muzzle device then you can take the bolts out and slip the hand guard off the mount. Gen 2 mounts are exactly the same size internally and only differ in their method of retention. A big spring clip for Gen 1 and a set screw for Gen 2.

Actually, I think I'll just keep it unglued, which seems the safe choice. That said, it looks like I could treat the handguard like a captured pin and never totally remove it again.

I found out I can slide it forward to the point the gas block is exposed without removing the muzzle device.

BTW, Rix, this is a little off topic, but I hear you got a Brownell carry handle scope onto a 1913 mount acog type mount for AR-180 use. Would really love to see an article on how you did it on AR-180s.com. Hint hint.

What's the ID of the handguard?

It's the handguard that comes with the BRN-180 upper. If you were looking for something more specific I don't know.
I haven't noticed any markings on it except for an M (which I think is because it's an M lock type.)

Sorry, meant inner diameter.

Ah, Okay. I had to dig out the calipers.

At the muzzle it's 31.03mms across. Or 1.221 inches.

The breach, where it sits on the barrel shoulder, is 24.74mm or 0.974 inches, If I'm measuing correctly. I didn't want to take it past the flash hider just yet, so I was measuring around the barrel, but I think I have that right. Give or take a half millimeter or thereabouts.

Dang, so about .010" too small. Too bad they couldn't have made it a tad larger.

I just ran into this issue on my gen 2 10.5 556. The handguard won't clear my warcomp. It looks like If I unscrew all 6 screws and completely take apart the handguard from the front trunion I might get enough room to service the piston. Should I send mine into you? To me this is a major design flaw in the handguard.

Exactly. Huge technical oversight in my opinion. I hope they can fix this with a gen 2.5. You need to rocksett your muzzle device if you can on using quick detach suppressors. Part of the lure of the brn180 is supressor use.