Hey guys,

Can someone talk me thru removing the A2 birdcage on my AR M&P Sport? I've had it for about a year and want to switch the standard A2 to something nicer.

Thanks in advance.

its not pinned or locked tight. just use a wrench & turn. just pay attention on how the crush washer is positioned. also the tread i believe is 1/2"x28

You're going to need a couple of vise blocks to hold the barrel. A couple of stout wooden blocks with a V cut in the middle with plenty of rosin should work. Brownells sells aluminum V blocks for ~$20. DO NOT put a bar through the front sight base.

IIRC, the torque value is less than 15 ft/lbs so massive holding power shouldn't be necessary. I would avoid Crescent wrenches or the like. Try to find an open end wrench that fits snugly.

If you don't care about the finish, a pipe vise will make sure the barrel doesn't turn

WR is correct, make sure the barrel is secured and consequently other damage will not occur. There is a lot of aluminum in an AR that will not take unusual stress.

Check out this thread, there are some good pictures and suggestions on how to secure your gun/parts of your gun for changing out muzzle devices.

Need to install barrel and flash suppressor. What vice block is everyone using? - AR15.Com Archive

I'm in the same boat as you in looking to change my muzzle device, and plan on using the wood block as a barrel clamp in the vise when I get to it. I plan on just putting the whole upper in there, with the wood barrel clamp as close to the muzzle as will still allow me the work space needed to complete the job.

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686/M&P9 Pro/M&P15X/M&P15-22

Thanks for the advice everybody. I've seen two different ways to do this, one with a upper receiver vise block and another with a barrel vise method. I think the barrel vise method would be more secure and it doesn't put stress on the upper. Is my logic correct?

You got it correct, pad and clamp hard as sometimes the little buggers can be troublesome. Never reuse a crush washer and index carefully (if needed) when installing.