Removing A2 flashhider and installing a FSC556....HOW?

[30in1]

I have a Daniel Defense M4 that I am removing a factory A2 birdcage and replacing with FSC556.

I called around to get it installed, but the shortest is a week turn-around time. This is my duty patrol rifle and I need it for work. Suggestion?

I do not have any specialized tools. I was told that all I need is a crescent wrench. Is that right? Should I worry about twisting the barrel, receiver, FSB, or rail without a receiver vise-block?

Also, the FSC556 has shims to make sure the ports line up right.

Thnx

[Singlestack Wonder]

The proper way to to this would be to have a receiver block (DPMS makes a good one). For as little as they cost, why take a chance and ruin the rifle? The FSC probably came with a crush washer which allows the proper timing of the compensator. You can do a search on how to install a muzzle device using a crush washer.

http://www.brownells.com/.aspx/sid=41189/pid=17094/sku/AR_15_Upper_Receiver_Block

[Belmont31R]

I use a 3/4" open ended wrench. Fits the flats just fine.


With the spacers you need to "time" the device to your barrel. You have to try different combo's of them until you get it lined up.


Looking down the barrel from front to back you want to be able to get the device to about the 1 or 2 o'clock position before tightening with the wrench. Much more than that and its going to require too much torque to time properly.


You don't need a vice block or anything to do it. Ive done plenty just holding the gun between my legs. Its not a barrel nut or anything.

[Buck]

WECSOG

Off with the old....

http://www.motorera.com/dictionary/pics/h/hacksaw.jpg


And on with the new...

http://www.tbi-industries.com/english/Produkte/MIG_Handschweissbrenner.jpg

;)

B

[Robb Jensen]

Proper way equals a vise , barrel blocks and a wrench.

[Mate]

This might get me flamed, but I just used a screwdriver.

[Robb Jensen]

This might get me flamed, but I just used a screwdriver.

I've seen some people do that but many times it results in damaged flash hiders and or damaged or broken screwdrivers. YMMV.

[kwrangln]

I guess the biggest question is what length is your barrel?

If you have a 14.5" barrel then your current FH is pinned in place and is going to take some work to remove and replace. Think grinder, drillpress, welder or torch.

If you have a 16" barrel then just unscrew and install the new brake as has been covered already.

[Mate]

Since he said DD M4, I'm gunna guess 16".

[Peanut]

This may be out of my lane, if so, sorry.

Doesn't the flash hider (A2) need to be torqued, then turned clockwise for TDC alignment.

Does the FSC556 need to be torqued?

[mpom]

Do it right yourself, as gotm4 suggested, or have someone else do it. Messing up a perfectly good rifle is an expensive lesson.
My flash hider was on supertight and I needed to add a soft plastic "liner" to the cheap barrel block I got from Brownell's, but nothing was bent or scratched.

[mark5pt56]

check zero after, mine was 4" off after putting one on.

[chadbag]

You can make an inexpensive barrel vise blocks out of wood -- 2x4. Cut a channel (can be a half-diamond channel) in the wood on both sides and use it to hold the barrel in the vise.

The FSC556 comes with a peel washer (or newer versions come with the peel washer already delaminated). If you will never use this with a Gemtech HALO (2008 or less) then you can just use a crush washer. Otherwise you use various pieces of the delaminated peel washer until you get it close to right and then torque it to right.

[Quib]

For FH/barrel work, I’ve used a thick section of rubber automotive hose, split lengthwise down one side. Place this over the barrel for protection, then place the barrel with rubber hose, into the pipe jaws of a standard bench vice.

[justpete]

FWIW, I've installed five FSC556s using peel washers. One was installed on a KG Koted SS barrel, two were installed with very little parked barrel available to clamp to, and two more were installed on easily clamped parked and SS barrels. Used a USGI wrench extension (cheap) on a 1/2" breaker bar (already had it) for removal and installation.

I've used leather pads (had 'em), magnetic vise caps with elastomer faces (had 'em), both at the same time, and all in a cheap 'gunsmith' vise from Midway (now bent and happily trashed) to install A2s, Phantom 5C2s, AAC Blackouts, etc. and basically it sucked. Serious pita having to set some in the vise vertically, some at an angle, a few across, and all twisted, none were rock solid which made it really difficult to time accurately with crush washers.

Changed to the Wilton vise recommended here (may be discontinued at Lowes by now) and used an aluminum barrel vise (a steal at twice the price) with and without rosin (made a huge difference and a lifetime supply from Brownells doesn't cost diddley - not to mention it makes a jim dandy flux for melting lead alloys) where there was enough barrel length and no marks were left on any of the barrels that couldn't be removed with some Hoppes. The rosin eliminated any marks at all since the barrels never slipped.

Hacked some heavy aluminum angle to form a couple of short pieces that together with the pipe jaws in the vise worked for the ones with DD M4A1 RIS II FSP fore ends. In all cases a Starrett machinist's level (already had it) was placed on the receiver rail and the barrel clamped down so it was level. Then placed the base of a small machinist's square (cheap from Enco) on the FSC556 flat as it approached TDC so the machinist's level could be placed on it to get it to TDC.

With peel washers a set of angle gages (again, cheap from Enco) were used to estimate the number of layers to incrementally remove. The level was left on the receiver as the muzzle device was slowly tweaked to make sure the barrel didn't slip. Worked very well but took a long time. OTOH, all of them are dead on within the error stackup and none are damaged in any way, neither are the barrels.

So, uh, what's all that mean? A good vise, well anchored (as in _really_ well anchored), an aluminum barrel vise or cut up pieces of heavy aluminum angle, some rosin, a USGI wrench extension, a 1/2" breaker bar, and either a good eye or a decent machinist's level or even a line level and a small machinist's square will get you there assuming you're not trying to drive yourself completely farkin' nutz with peel washers. If so, buy a bunch of 'em, trust me.

Or you could wait until someone's available to do it right for you. If you plan on working on it some more nothing's a better investment than tools, metrology, and gages. No sense dropping that kind of coin on a rifle and not spending a very small amount extra, comparatively. The FSC556 is a hundred bucks so investing an equal amount or so in tooling to properly install it seems reasonable at least to me. YMMV.

[kwrangln]

FWIW, I've installed five FSC556s using peel washers. One was installed on a KG Koted SS barrel, two were installed with very little parked barrel available to clamp to, and two more were installed on easily clamped parked and SS barrels. Used a USGI wrench extension (cheap) on a 1/2" breaker bar (already had it) for removal and installation.

I've used leather pads (had 'em), magnetic vise caps with elastomer faces (had 'em), both at the same time, and all in a cheap 'gunsmith' vise from Midway (now bent and happily trashed) to install A2s, Phantom 5C2s, AAC Blackouts, etc. and basically it sucked. Serious pita having to set some in the vise vertically, some at an angle, a few across, and all twisted, none were rock solid which made it really difficult to time accurately with crush washers.

Changed to the Wilton vise recommended here (may be discontinued at Lowes by now) and used an aluminum barrel vise (a steal at twice the price) with and without rosin (made a huge difference and a lifetime supply from Brownells doesn't cost diddley - not to mention it makes a jim dandy flux for melting lead alloys) where there was enough barrel length and no marks were left on any of the barrels that couldn't be removed with some Hoppes. The rosin eliminated any marks at all since the barrels never slipped.

Hacked some heavy aluminum angle to form a couple of short pieces that together with the pipe jaws in the vise worked for the ones with DD M4A1 RIS II FSP fore ends. In all cases a Starrett machinist's level (already had it) was placed on the receiver rail and the barrel clamped down so it was level. Then placed the base of a small machinist's square (cheap from Enco) on the FSC556 flat as it approached TDC so the machinist's level could be placed on it to get it to TDC.

With peel washers a set of angle gages (again, cheap from Enco) were used to estimate the number of layers to incrementally remove. The level was left on the receiver as the muzzle device was slowly tweaked to make sure the barrel didn't slip. Worked very well but took a long time. OTOH, all of them are dead on within the error stackup and none are damaged in any way, neither are the barrels.

So, uh, what's all that mean? A good vise, well anchored (as in _really_ well anchored), an aluminum barrel vise or cut up pieces of heavy aluminum angle, some rosin, a USGI wrench extension, a 1/2" breaker bar, and either a good eye or a decent machinist's level or even a line level and a small machinist's square will get you there assuming you're not trying to drive yourself completely farkin' nutz with peel washers. If so, buy a bunch of 'em, trust me.

Or you could wait until someone's available to do it right for you. If you plan on working on it some more nothing's a better investment than tools, metrology, and gages. No sense dropping that kind of coin on a rifle and not spending a very small amount extra, comparatively. The FSC556 is a hundred bucks so investing an equal amount or so in tooling to properly install it seems reasonable at least to me. YMMV.

Pete, I'm right there with ya on the OCD when it comes to putting something together. When installing a brake/compensator though, it really isn't necessary, and some benefit can come from having them slightly off. Since each shooter is different, some may find that even though the brake is taking care of muzzle rise, it still tends to move slightly to one side upon recoil (to the right in my case). Turning the brake a degree or two in this direction can help counter this and really keep the muzzle still. I believe it's Benny Hill (someone correct me if I am thinking of the wrong name) that says his comps are a starting point, and encourages users to tune them to their personal preference. While most are unwilling to take a file/drill/dremmel to their brake, just a bit of turning can sometimes make a difference in their performance.

Just a thought.

[Nam62]

I changed the flash suppressor on a Ruger SR-556 and did not use vice. First I found a piece of steel to fit in the end of the flash suppressor on the Ruger SR-556 then with rifle magazine facing me I applied pressure with a crescent wrench (do not use excessive force Just steady Pressure) It will snap free.

Turn rifle over so magazine is facing other direction.

To install the FSC556 just make sure it will hand tighten to 20 to 30 degrees (use shims to get the correct spacing) before it's tight. Than tighten till the trade mark is level with the top of the receiver.
No torque wrench is required.

The PWS web site has the instructions there for installation.

PDF. instructions link: http://primaryweapons.com/store/pc/documents/FSC556.pdf

Primary Weapon Systems web site.

http://primaryweapons.com/store/pc/home.asp

[justpete]

Pete, I'm right there with ya on the OCD when it comes to putting something together. When installing a brake/compensator though, it really isn't necessary, and some benefit can come from having them slightly off. Since each shooter is different, some may find that even though the brake is taking care of muzzle rise, it still tends to move slightly to one side upon recoil (to the right in my case). Turning the brake a degree or two in this direction can help counter this and really keep the muzzle still. I believe it's Benny Hill (someone correct me if I am thinking of the wrong name) that says his comps are a starting point, and encourages users to tune them to their personal preference. While most are unwilling to take a file/drill/dremmel to their brake, just a bit of turning can sometimes make a difference in their performance.

Just a thought.

Good idea too! I hadn't considered it as my shooting isn't nearly consistent enough for a tweak like that to matter, yet. Will keep it in mind though, thanks for the tip.