Hi all,
I ordered my first BCM upper recently, and it’s coming with their BCM Mod0 Comp already installed. I’d like to try a simple A2 flash hider. What is the proper procedure for changing a flash hider, and what tools will I need for the job? Thanks.
Chris
Try the comp first. I kills flash pretty well.
C4
I definitely will, Grant. Just planning ahead. I normally wouldn’t have gone with a comp at all due to increased blast (just use an A2), but the BCM upper sale had the comp already installed.
By the way… thanks for the fast processing and shipping on my new BCM lower. 
You actually need several tools to do it PROPERLY so I would suggest taking it to a professional armorer.
As the shooter, you won’t notice any increased blast.
C4
I’ll take one for the team and Trade you an A2 for that comp. :sarcastic:
(find someone with a Geissele reaction rod to do the swap)
A sturdy workbench, good vise, aluminum jaw inserts, wrench that fits the comp and a new crush washer. Depending on the hand guard, barrel and gas length you may also need the tools to RR the rail to have enough barrel to grab. You are probably better off doing what Grant said…
If you have the proper tools it is easy peasy.
Key words in red. Be sure to clamp the barrel in a vice. Do not use a receiver block or you take a chance of screwing the barrel out of the extension or shearing the locating pin.
Ive used both, I personally dont notice much of any difference in blast or muzzle flash between the two. And recoil reduction is so subjective from shooter to shooter and gun to gun that I dont know if it can even be used as a “this is better than that” argument.
I personally wouldnt go through any trouble at all to swap from the BCM comp to an A2 at least without shooting them.
Its not like the BCM comp is a muzzle brake.
My first muzzle device install involved a bundle if mousepads, a towel, and careful tightening on a benchvice until it JUST didn’t move around when I wrenched the old A2 off. My accuracy was not affected and I didn’t mar the barrel. I now use a Reaction Rod and suggest that you buy the same or the Brownells tool.
People on this forum have disagreed on this. But I always use a Brownells barrel extension torque tool when installing or removing muzzle devices on an AR style gun.
It’s like a generic Geissele Reaction Rod. The Brownells tool is less than half the price, but is still a very high quality product.
I would suggest not using a upper receiver clamp/block to hold the barrel while you turn the muzzle device.
Joe Mamma
Just shoot it with the BCM Comp installed… you won’t want to go back to an A2.
Go to YouTube and watch half a dozen people swap out muzzle devices and you will see what will work.
If you change M devices with a reaction rod or Brownel’s tool enough times you will remove the barrel extention! Ask me how I know???
How do you know?
In all seriousness, barrel extensions are supposed to be torqued to 150+ ft. lbs. Muzzle devices shouldn’t be tighter than 25-30 ft. lbs.
I would think repeatedly removing muzzle devices that weren’t over-torqued onto the barrel should not cause the barrel extension to unthread unless it wasn’t torqued on properly in the first place. The torque ranges are so far apart that it’s not like you’re slightly loosening the extension each time.
I understand your logic but it happens. Where did you get the 150FP number?
Taking into consideration both parts heat and cool hundreds of times and all the cleaning solvents and oil that stays inside the barrel extension soaking into the threads? Some extensions will never come off, some come off easy. If you take a chance and it spins, it’s a quick trip to a smith to re-torque and hope it lines up.
Barrel extensions are torqued at whatever that manufacturer does it at. They are at least 125 ft./lbs from what I have seen on various prints and speaking with other people. I have been using the Reaction Rod almost since it’s intro and use it all the time during installation and removal.
Never had a barrel extension come loose.
Before I got all the proper tools, I installed a SF brake by holding the rifle between my legs (sitting down with buttstock between feet, muzzle facing up) and using a crescent wrench to remove the A2 and installing the brake. Having the proper tools though makes it so much easier.