Does this AR exist (or can it be built?)

[JHE1956]

I'm considering what I would like in an AR, and have started shopping around either for something off the shelf or for the parts to build it. But I'm pretty new to the AR-15 world and may be looking for the unobtainable.

Here are my specs:

16 inch HB (gotta keep in Maryland legal)
Fixed rifle length stock (I like the Magpul MOE, or something similar)
Flat top receiver
folding iron sights
Rifle length front handguard (I like the style of the Magpul handguards but suppose I would need a rail for the front sight) and sight radius (this is what seems to make it difficult)

What I'm thinking about is something like the Vietnam era CAR-15 carbine (Colt model 605A, the one where the barrel was shortened to just in front of the front sight) but up to date with a heavy barrel.

http://m.gandermountain.com/modperl...rnment-Carbine-Centerfire-Rifle&i=UF103763470

I'm hoping this can be done reasonably with standard components, but will not be surprised if my eclectic tastes cross over in the area of "not available."

 

[BUFF7MM]

There's so much stuff out there you can probably find just about anything/anyway you want to build an AR, it's just how much time and money you're willing to spend to get what you want.

 

[jimbobborg]

You want a 16" Dissipator upper, something like this http://palmettostatearmory.com/psa-16-mid-length-dissipator-without-bcg-or-charging-handle.html with a heavy barrel to remain Maryland compliant?

 

[fred333]

Someone may be making exactly what you're looking for, but I don't know who? Still, your best bet is to assemble it yourself. That way, you get what you want and can decide whether (and where) to spend extra for additional quality/features...or not.

Also, if you're aiming at a 16" HBAR solely to sooth our nanny state overlords, have you considered an SBR (i.e., build a short-barreled pistol and submit a Form 1 to ATF so you can attach a stock)?

 

[tkd4life]

I think one of the toughest things you will run into with that build is having a 16" barrel with a rifle length gas system. I've heard that can cause reliability issues as the bullet dwell time in front of the gas system till leaving the barrel is too short for an AR. You don't get enough gas into the system for it to function properly. That is why the midlength gas system was created. But they are out there if you really want it. You definitely can build what you are looking for. Will it work right... well why not give it a try?

 

[mopar92]

PSA sells dissipator uppers with HBARs and just get a stripped lower and add whatever stock you wish. I'd recommend the Cavalry Arms A1 length stock.

 

[clandestine]

I think delton sells 16" HBAR dissipator barrels with rifle gas.

If you cant find one buy a 20" HBAR and have it cut and threaded to 16". Have the gas port opened to .110 and it will run.

 

[BUFF7MM]

Barrel:
http://www.del-ton.com/Del_Ton_Barrels_p/bl1017.htm
Upper assembly:
http://www.del-ton.com/AR_15_Barrel_Assembly_p/dt1026.htm

 

[JHE1956]

I think one of the toughest things you will run into with that build is having a 16" barrel with a rifle length gas system. I've heard that can cause reliability issues as the bullet dwell time in front of the gas system till leaving the barrel is too short for an AR. You don't get enough gas into the system for it to function properly. That is why the midlength gas system was created. But they are out there if you really want it. You definitely can build what you are looking for. Will it work right... well why not give it a try?

I get what you are saying about the gas system. The important thing for me is the sight radius, so if the gas block is hidden under the handguard and the front sight is rail mounted near the muzzle, that is fine with me. Olympic makes a rifle like that, (adjustable stock but I can change that) but not in a heavy barrel.

( Although it is interesting that the Garand works OK with its gas port right at the muzzle)

 

[clandestine]

I get what you are saying about the gas system. The important thing for me is the sight radius, so if the gas block is hidden under the handguard and the front sight is rail mounted near the muzzle, that is fine with me. Olympic makes a rifle like that, (adjustable stock but I can change that) but not in a heavy barrel.

( Although it is interesting that the Garand works OK with its gas port right at the muzzle)

The gas system works fine with rifle gas and a 16" barrel. The reason the abandoned that setup for a military application was poor cold temp and high altitude performance (cold temps=lower pressure and sluggish moving parts).

They run just fine with rifle gas and a 16" barrel. I build countless units that never saw problems.

 

[NateIU10]

Folding front sight or fixed? We can build whatever configuration but have some dissys floating around w/ middy gas/Fixed rifle length FSB, and have a rifle length gas 16" barrel floating around also.

 

[tkd4life]

I get what you are saying about the gas system. The important thing for me is the sight radius, so if the gas block is hidden under the handguard and the front sight is rail mounted near the muzzle, that is fine with me. Olympic makes a rifle like that, (adjustable stock but I can change that) but not in a heavy barrel.

( Although it is interesting that the Garand works OK with its gas port right at the muzzle)

The garand doesn't use a direct impingement gas system. The piston located on the garand is only a couple of inches from the gas port. The same is true for the M1 carbine, the M14, and most piston driven AR's. All of the above have rods that transfer energy to the bolt to cycle the action. But it sounds like you are looking to stay with direct impingement. Gas pistons and direct impingement are totally different animals. The gas tube of an AR has volume and you have to fill that volume of air with high pressure gas to activate the gas system. The longer the tube, the higher the volume, the more mass of air needed to achieve the same pressures. If you dump pressure at the end of the barrel (bullet leaves muzzle) and there isn't enough gas to flow through the gas system, into the action to cycle the bolt, you have issues. That is why the military dumped the idea. The reliability just wasn't there.

But Cladestine is right, you can bore open the gas port to a bigger diameter, letting more gas into the gas system and it can fix the problem with cycling, but it also leads to other issues like gas port erosion and throwing more dirty gas into the receiver. It is all about the trade offs.

 

[DaemonAssassin]

Folding front sight or fixed? We can build whatever configuration but have some dissys floating around w/ middy gas/Fixed rifle length FSB, and have a rifle length gas 16" barrel floating around also.

OP, talk to the boys at Engage. They have my business and they have always treated me right. Watch out for the calf cleanings, by Brutus.

 

[JHE1956]

Folding front sight or fixed? We can build whatever configuration but have some dissys floating around w/ middy gas/Fixed rifle length FSB, and have a rifle length gas 16" barrel floating around also.

Was thinking folding.

 

[JHE1956]

The garand doesn't use a direct impingement gas system. The piston located on the garand is only a couple of inches from the gas port.

Good point -- if I had thought about it more I would have realized that.

 

[SigMatt]

I'm considering what I would like in an AR, and have started shopping around either for something off the shelf or for the parts to build it. But I'm pretty new to the AR-15 world and may be looking for the unobtainable.

Here are my specs:

16 inch HB (gotta keep in Maryland legal)
Fixed rifle length stock (I like the Magpul MOE, or something similar)
Flat top receiver
folding iron sights
Rifle length front handguard (I like the style of the Magpul handguards but suppose I would need a rail for the front sight) and sight radius (this is what seems to make it difficult)

What I'm thinking about is something like the Vietnam era CAR-15 carbine (Colt model 605A, the one where the barrel was shortened to just in front of the front sight) but up to date with a heavy barrel.

http://m.gandermountain.com/modperl...rnment-Carbine-Centerfire-Rifle&i=UF103763470

I'm hoping this can be done reasonably with standard components, but will not be surprised if my eclectic tastes cross over in the area of "not available."

I have that exact configuration in my safe with the exception of the flip front sight. A 16" Dissipator, rifle length handguard (I took off the rail but it had one), fixed A2 stock, A4 flattop, flip rear sight, red dot cowitnessed to the front fixed sight.

I have a 20" A4 in the configuration you describe exactly. Rifle length rail, flip front/rear, EOTech holosight cowitnessed to front sight, fixed Magpul MOE stock.

Not really a hard configuration to build.

Matt

 

[dreadpirate]

Windham Weaponry has an HBAR Dissy but with a carbine gas system. [EDIT - might want to give Engage a try first since they are local]

 

[Magnumite]

Very basic rifle, nothing to write home about, but it is similar to the one you're working toward. The barrel is a cut down Colt 20" HBAR. I have since put MBUS front and rear sights on it. This one has a scope on it.

http://www.mdshooters.com/showthread.php?t=191315

 

[Hog Sniper]

Dread beat me to it. The Windham Dissy is a nice choice...

 

[MKR03]

So you don't have a preference on gas system length, you just want a rifle length handguard to give you a longer sight radius for you iron rights? If this is correct, your options are endless. Find a 16" heavy barrel, low profile gas block (doesn't matter what gas length you go with) and a long handguard that will cover the gas block (I actually like the look of s 15" rail over a 16" barrel).