is it just a special version to build 14.5+1.5in non taxable barrels? How long is the version for NFA and millitary weapons if it is different?
And btw, how long is a A2 birdcage in comparison?

IIRC the A2 is about 1.25" and the others are more than 2".

The Phantom adds 1.6" to the overall length of the barrel and the Vortex adds at least 1.6".

What the heck are you guys using to measure the Phantom and Vortex?  It sure ain't a US inch  measurement tool!  [;)]

The Vortex is 2.22" long, call it 2-1/4" long.  The M16 compensator is a nominal 1.8" long, call it 1-3/4".

If you screw a 1.5" muzzle device onto a 14.5" barrel the overall length will be roughly 15.5" depending on the [b]overlap[/b] of the threaded area.....

-- Chuck

Chuck, you are correct.  My bad!  I was tired and my post was edited to what I really meant to say.

Oh, I see, so the threaded area on a GI/pre-ban AR barrel is about 3/4" and the Vortex and Phantom project about 1.5 inches beyond the muzzle and the birdcage projects about 1" past the muzzle.

Am I correct?

And there is only one version each of the Vortex and Phantom. Not a special long version for civilians and a shorter version for GI use, correct?

[b]"And there is only one version each of the Vortex and Phantom. Not a special long version for civilians and a shorter version for GI use, correct?
"[/b]

I have heard that some Delta Force and Israeli Defense Force operators along with the DEA use Vortex Flash hiders.

With the development of the KAC QD suppressor I would think that this must be on the decline. As sound suppressors offer a 100% reduction in flash after the first round.

The phantom, however, I have never heard of being used by any military or agency.

One of the problems with the aftermarket flash-hiders is that sometimes they will not accept a blank-firing adaptor and these are important for training which these guys do A LOT OF.

If you need 1/10 of an inch why not just get a 1/10 of an inch piece of metal with a hole in it (made to the same diameter as the barrel) and put this over the threads and tighten down the Vortex and weld this together?

Walla 1/10 of an inch longer (a machinist could make you one of these for less than $20.00

To my knowledge the Vortex was designed to be as short as possible and maintain near 100% flash elimination; but without any thought of bringing 14.5" M4 bbls out to NFA required 16".  The later Phantom and "tactical" Vortex post date the popularity of the M4 barrel and probably maintain their lengths for this purpose as well as flash supression.

The USGI M16A1 compensator (full birdcage) on one of my rifles projects 1.157" from the front of the barrel.  Since it's threaded it could easily be mounted 1.2 or even 1.3" and then welded in place using washers to fill the interim distance or Greeno's idea of the washer under the device -- between the muzzle and the device.

I'm not sure how well a 1-3/4" device would fit on the barrel with less than 1/4" thread overlap when it's designed for at least twice that thread.

The M16A2 compensator is a couple hundreths longer than the M16A1, the XM16 3-prong is in between.  At least on the three samples I have, I've no idea of the length tolerance.

-- Chuck

Can anyone with an A2 and a Vortex handy measue the distance on both between the base and the rear edge of the slots?  I think the Vorex has a greater distance before the slots open, and would be what I am looking for to mount on a pre-ban mid length barrel, as the lug is just a little far foreward on these, and some extra non-ported length on the FS would really help.  
Thnx

OK, here are my measurements from aft end to where the slot meets the bore.

These distances will vary depending on how tight you screw the device on the muzzle.  The M16A2 compensator only indexes on a full thread, all the others are non-indexable and can be set deeper or shallower.  I recall the thread pitch is 1/24 inch (but someone will know for sure!).

XM16E1 (3 prong):  1.0"
M16A1 (birdcage):  .81"
M16A2 (no bottom slot): .75"
Vortex:  .82"
Phantom:  .78"

Note the slots on the Vortex and Phantom are straight cut from outside to the bore, the USGI slots are tapered so the outside of the slot is longer than the inside.  Measurements were made to the edge of the [i]inside[/i] of the slot.

-- Chuck

Just checked my notes:  Thread is 28 NEF (1/28 inch), so a full turn would be .0357".

-- Chuck

THANKS!
rather than totally hijacking this thread:
[url]http://www.jobrelatedstuff.com/forums/topic.html?b=3&f=12&t=146508[/url]