I am thinking that if I upgrade my Postban M4 to a No Ban, I may as well do a perm attached A2 flash hider so a Std. Bayonet will work. I would think that many would do this if legal , but I have never read anything about doing this.  

Any thoughts?

TIA,
Echap

Standard bayonets will work with 14.5" barrels with A2 hiders, so therefore, it would not be legal, since the A2 doesn't take your barrel length out to 16".

If you want to make a 14.5 barrel legal and still accept a bayonet, the Gemtech Bi-Lock works great.  Gemtech will laser weld it on for 30 bucks, I believe.

a phantom or vortex will do good to get you to the legal length also

Quoted: a phantom or vortex will do good to get you to the legal length also

Will the Phantom thread on?  

Quoted: Quoted: a phantom or vortex will do good to get you to the legal length also Will the Phantom thread on?

Either of those are thread on, but they won't mount a bayonet.

Phantom is not narrow enough to fit the bayonet?

My Vortex allows the bayo to mount.

Bob

I just permanently affixed my Vortex to my 14.5" bbl tonight after work.  

My plan was to drill a 3/16" hole through the f/s into the bbl a bit.  Then my clever ass was going to find a drill bit 1/64" smaller in dia, slip it in there, slap a small tack weld over it, and no one would be the wiser.  Even planned on doing this on the bottom of the bbl so it would be even harder to notice.

It did'nt happen that way...

The punch that I was using was not leaving a punch mark in the f/s to get the drill bit started.  So I hit it REAL hard....  You all remember some of those bunk Vortexes that were running around out there?  The tines were blooming (opening up)?  I guess something went wrong with the heat treatment in those.  Well, I think I got one of the good ones!  Cause the tip of the punch broke off and went pretty deep into the palm of my hand.  

Needless to say, my Vortex did not become blind pinned.

What's that you say?  Why you're right.  At the beginning of this post I DID mention that I perm affixed my Vortex.  Via my trusty mig welder.  Yup.  Three tacks: 3, 6, and 12 o'clock.  Not to bad.  Don't think it will be falling off any time soon.  Does'nt look as gaudy as some make it out to be.  Wait a minute...Yes it does.  But my AR is not a safe queen so this helps give it that "custom" look.

"Flintstones...Meet the Flintstones..."

The Phantom is not narrow enough to mount the bayo.

Just double check, the Phantom is not narrow enough for bayo, but Vortex is?  This is if they are on mounted on 14.5" to make it 16" legal.  I want one like that, but still able to mount bayo.

The Phantom does accept the Bayonet.
Both versions, the M7 and the M9 fit just fine.