[HK SD9 Tactical]

I was hesitant to do it myself as well. I read up a lot on this particular subject and it is much easier that you think. You do not need to remove the barrel to do this. DO NOT use the jam nut when replacing your flash hider/brake. Depending on the Omega, you may either need a Surefire support ring or a BKA support ring, unless one came with the muzzle device. You will also need shims to time the brake properly. Get some RockSet as you will need that as well to ensure that the brake does not come loose. Using RockSet also allows you to not have to torque the muzzle device to the specified amount which IMHO is too much.

I just installed the AAC 51 tooth Muzzle Brake on my SCAR 17 and it worked out just fine. Make sure you do a couple of dry runs on the muzzle device before your final installation. Make sure you get the right amount of shims in place so when you torque it to your preference, it will be timed correctly.

KBA: KBA Custom SCAR 17 Shoulder Ring (Forum Sponsor)

RockSet can be had at Brownells or any number of firearm places. Be prepared to buy the smallest bottle which is 2oz and it is more that you will ever use in a lifetime.

Jeremy at Silencer Shop (Forum Sponsor) is probably the best source of information on the installation of this particular muzzle device onto the SCAR17.

 

[HK SD9 Tactical]

What if you only want to replace it with a standard flash hider & no sound suppressor. Will the jam nut work ok with that setup?

Info that I have seen is NOT to use the jam nut with any type of flash hider or brake. It is to be used with the original FH/B that is on the firearm as shipped. It appears that the jam nut may cause issues if used with anything else.

 

[HK SD9 Tactical]

I installed an ASR brake on my 17 for an Omega also. Removing the old brake was easy with two wrenches and required no vise. Clean threads thoroughly. I used a KBA ring and shims to hand tighten the ASR brake to about 10 o'clock. Put the barrel in a vise, sandwiched between two blocks of wood (with grooves drilled in) and rosin (to keep from slipping). Applied Rockset. Torqued to 20 in-lb and twelve o'clock. Let cure overnight and done.

Think you mean 20 ft/lbs

 

[HK SD9 Tactical]

So if I wanted to mount a flash hider, all I have to do is remove the muzzle brake and locking ring and then HAND TIGHTEN the flash hider down with rocksett? Without torque on the flash hider I can mount a suppressor without fear of my flash hider backing off?

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RockSet is good stuff. I would torque it down somewhat but you do not have to torque it down to 25ft/lbs. I suspect that with RockSet, once cured, it will handle the heat and vibrations. Because you mentioned a suppressor though, I would torque it down a little. maybe 15ft/lbs or so. I have never run a test without torquing it down and just using Rockset. Make sure you have concentricity.

High temperature Rocksett all-purpose ceramic adhesive cement
Features:

• Incredible temperature resistance, -350 degrees F up to 2,015 degrees F
• Intended for use on threads an cylindrical assemblies (flash hiders & muzzle brakes)
• In addition to acting as an adhesive, Rocksett acts vibration dampening material
• Non-toxic, odorless, and non-flammable
• Withstands oils, fuils, acids, and alkalis
• Long shelf life
• No mixing or priming required
• Bonds ceramic, glass, and metals
• Surfaces to be bonded should be dry and grease free
• Ships in a 2oz bottle

Benefits:

• Extremely high temperature range makes Rocksett ideal for attaching muzzle devices
• Several suppressor manufacturers use Rocksett to ensure that muzzle devices to not loosen when used in conjunction with a suppressor

Make your own decision as to how much you want to torque it down.....

 

[HK SD9 Tactical]

Great! For future reference, could you remove the muzzle device that has Rockset or loctite applied without a vice? I assume you would need a torch

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Soak in water for 24 hours before attempted removal. Immersion in water for that amount of time will release the rockset.

As fart as torquing the 25fl/lbs without a vise, I would like to see that. I tried to torque to 25ft/lbs IN a vise with vise barrel blocks and it still turned before I reached the amount quoted.

Use a vise with some type of barrel blocks, either a 2X4 with a hole drilled down the center then cut in half or something similar. Use a smaller diameter drill bit than the barrel. Or use vise barrel blocks made of aluminum (what I have) and I use leather straps on either side of the barrel to lock the barrel in place with no damage or marring to the barrel.

 

[HK SD9 Tactical]

I do it all the time with naught but a set of Craftsman crow's foot wrenches and a HF torque wrench. Water for Rockset and MAP gas for loctite before I start cranking. Besides I'd rather rely 100% on a counter wrench than than applying direct torque to my barrel in a vise any day of the week.

Unfortunately, for the SCAR17, there is no place for the counter wrench for installation otherwise that is the methodology I prefer as well.