What is the recommended torque spec for muzzle devices?  I have a story to tell afterward

In

I was always told to put some body weight into it and it'd be fine.

It depends heavily on what kind of ring you use under the muzzle device and what the kind of device it is.  Cut washer and regular A1 birdcage, I usually just get really snug, no forcing it.  The cut in the washer will prevent it from slipping away and there isn't too much to make the birdcage off.  Using the crush washer is for timing the devices, like A2 birdcage with a closed bottom.  You can snug the washer all you want without breaking anything, if you back off and on a few times.  These are meant to wear down with each pressure twist.  

Supressor mounts are a different story.  They don't get any washers, normally, because they bottom out on the thread shoulders.  You have to degrease the threads on the muzzle and the mount itself and use rock-set (it comes with all AAC mounts) so the mount does not come loose during fire.  Rock-set has to cure for 24 hours before use.  Back to your question: just make it nice and snug, don't get it to the point where you have a neck cramp from tightening it.

Don't use lock-tite on anything as it will melt off from any heat.

15-20 ft/lbs for an A2 per TM 05538C-23&P/2

I wrenched on as hard as I could and slathered on the Rocksett.  

What happened today was I went to remove my Gemtech HALO and after decoupling the collar the suppressor came off with the muzzle device inside of it.  I am very thankful I didn't shoot my suppressor or blast it off the gun but am seriously wondering WTF happened.

Did you de grease the threads on the barrel and the mount?

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Roger.

Torque specs for Muzzle Brake are correct - Cans that come with a QD Muzzle Break (like YHM) recommend 30 to 40 lbs of torque (I know WOW). I found that Ruger makes a a very thin spring steel washer (like paper thin) they call a Barrel Cap Spring (part no. A03660) it is between the barrel and the thread protector on the Ruger 22/45. I liked it so much (makes removal of the thread protector for replacement with a can a simple hand twist AND they don't twist off by themselves ) that I ordered a dozen of them and put them on everything I have with a threaded barrel (1/2"x28tpi of course). Give them a call and they will send them off to you USPS - you'll have them in a couple days. The best $20 you'll ever spend. I even used them with my YHM QD because I don't like torqueing stuff down on the front of a barrel and Lock Tight is a NO-NO. The Barrel Cap Springs do the trick still tight enough to use the QD with out disturbing the Muzzle Break - no muss, no fuss, no wrenches

For some reason I got set in just putting a drop of rocksett on the front and rear threads and snugging down my AAC mounts. (the brake had to be timed obviously) and it is a pure bitch to remove. Before I bought a proper barrel vice and wrapped it up in an old leather sling, I thought heating the device up with a MAPP torch did the trick. But apparently just leverage got them off.

In a nutshell, just a drop or two of rocksett should be more than enough to keep a muzzle device on.