Remove one AR flash suppressor and install another? (A2 to 3-prong)

[MatthewVanitas]

Tried running searches under "flash suppressor" and "remove", "change", etc., but no dice thus far.

I have my A1-sights, M4-profile Dissipator upper. Just waiting, impatiently, for my Stag lower to come in. I had thought of doing this project as a "retro" build, so had ordered it threaded w/o FS and order a 3-prong from DPMS, but Bushmaster tossed an A2 onto it anyway. Not sure if they confused my order, or just have a policy against mailing unprotected threads.

So, I want to remove the A2 and install a 3-prong. I have a crush washer and a peel washer on standby.

Do I just pad my vice-grips with some masking tape and twist off the old FS? Do I need to put it in a workbench vice (which I don't have), or can I just get a good grip on the barrel while twisting the FS?

To install the 3-prong, I understand that I just put on the washer and screw it down. If I use a crush, I just use brute force until it's timed right, if I use a peel washer, I peel off another layer if it's not timed where I want it?

Which washer should I use, and which should I give to a buddy to install my old A2 FS on his SU-16C?

Really dumb question: I put one prong of the 3-prong at the 6-o'clock position, in order to minimize kicking up dust, right? So prongs at 2-6-10-o'clock?

Thanks for any info, though I'm pretty sure someone will punch in some blindingly obvious keywords into search, drag up an old thread covering exactly this, and I will be fully pwn3d.

Thanks for any advice,

-MV

 

[444]

I would remove the flash suppressor with a cresent wrench. Make damn sure you don't twist hard enough to bend anything. I have a vise block made for this specific purpose. Without one, be careful.
I have removed a flash suppressor by keeping the whole rifle assembled with a magazine seated in the mag well. The rifle is lying with the muzzle to my right, magazine pointing toward me, barrel hanging off the end of the table. I then wrenched it off: no vise needed.
I have never used a three prong flash suppressor. I have put on the standard GI flash suppressors as well as the ones used for an AAC sound suppressor. I didn't time anything: I just screwed them on tight with blue loctite.

 

[swingset]

Get a barrel vice, or make one with a good piece of hardwood drilled out to the barrel diameter.

Do NOT try to take it off without it, you'll flex the receiver, the sight tower, etc. Chances are good it's really on there, you'll want to vice it up.

Once it's off, you will want a 3-prong wrench because it's round on the end, and does not have flat engagement surfaces for a wrench like an A2 has. You can make a wrench easy enough, but they also sell them cheaply enough.

You're right about the indexing of the 3-prong, but it's not necessary, just the way most people do it (closed off at 6oclock).

 

[MatthewVanitas]

Hmmm... I tried it very, very carefully with a money-wrench, and no give. Emailed Bushmaster, and they verified that it isn't on there permanently.

Some folks on AR-15 say that they've held the rifle still with a barrel wrench and then gotten it off, so I might bring my upper to the next SAXET gunshow and see if one of the builders there can spare a minute for a six-pack.

I tried ordering it w/o FS, but must have been a minor mixup.

Thanks for the tips thus far. Whatever I do, I'll be very, very careful.

-MV

 

[BIGPHIL]

If it came from Bushmaster with the FS on there, it will be tight. You will probably have to use a barrel vise or an action block. I prefer the action block myself. It's an excellent $40-50 investment. You will use it along with a vise to change your upper receiver config many times over (barrels, handguards, floattubes, FS, etc).

 

[Cavalryvet]

I got the suppressor off of my Armalite m15a4c SPR no prob but there wasnt a washer just grease?
how hard do I torque the YHM Phantom Flash Hider 5C2 in it's replacement also my m15a4 didnt have a washer should that be a concern? I did buy it used thanx for your help on my first post!

-jW