So I currently have my ar set up with a 16" daniel defense s2w barrel. It's accurate and shoots like a dream. The only problem is the barrel's weight. I was thinking of going with a 14.5 dd government profile barrel and was wondering if anyone knew if there would be enough of the muzzle device sticking out. I have the slr rifle works solo 15" (measures at 14.87") and a pws triad (measures 2.2")

A 14.5" barrel should have about .625" of thread, so if your muzzle device is 2.2" long then the whole assembly from after the extension to the tip of the muzzle device should be about just over 16" long. Since your rail will cover 14.87" of that 16", you will have 1.2" of muzzle device sticking out. You do not want any of the prongs on the muzzle device to be under the rail causing gases to be shot directly at the rail, which could cause your rail to blow apart (as recently seen in another thread here). So, Pending the space from the rear of the muzzle device to the rear of the prongs is over 1" you should be fine. Using a crush washer will give you a little more clearance.

I recently built one with identical specs.  I am going to pull the 15" rail off.  It covers too much of the flash hider.  I do not approve of the flash vents under the rail.  Some may be ok with it.  Also, my barrel is a 14.7 PSA barrel.  I do not think this works out with an A2 type flashider.  Might work out with a linear comp.  



I would not, and will change mine, build at 14.5/15" with anything resembling and A2 or phantom type flashider.  



 


Your Triad may yield different results.  Use this photo to gauge. That is a 15" Midwest Keymod.





 

Use a KAK slim comp 25 plus shipping to your door.  I just mounted a 14.5 barrel with a 15" handguard as well.  You need to make sure your rail will slide over everything once the comp is pinned to the barrel.  I cheated and drilled a hole in my comp then a small amount into the barrel with the comp in place backed it out used a tap set for 8/32 screws tapped the comp made a point that fit into the end of the barrel threads and then put the comp back on aligned it and put the screw in with a screw driver.  verified I couldn't budge the comp with a wrench then I just simply nipped the rest of the screw with a dremel cut off wheel and slowly ground it down.  then just covered it with BBQ black its under my rail so you really can't see it.  But it cost me a whopping 4.55 to pin my compensator to make it legal...

I appreciate the feedback. I think I will just end up sticking with a 16" barrel just to be safe. The triad works in theory, but best not to tempt fate.

15 inch rail on a 16 inch barrel is good choice.

I would not go longer than a 13 inch rail on a 14 inch barrel

PIC: 15 inch rail on 16 inch barrel with A2 style flash hidder