Latest issue of Spec Weapons for Mil & Police has a piece on a Arms Tech offering which features some interesting innovations.  Just wondering if this thing is the real deal or is it hype.

Gas Trap System -- Reduces port pressure.  Eases extraction. Reduces cyclic rate when in FA.  Also provides some degree of self cleaning so you end up with reduced amount of crud being blown back through the tube into the acton.

New Barrel Alloy -- Claims significantly longer service life than standard M4 barrel.  Many thousand rounds more, maintains accuracy much longer accross its life.

Gain twist, polygonal rifling -- Claims increased velocity.  Their chrono test showed their 10.5" barrel was slightly quicker than a new 14.5" M4 barrel w/SS109.

They also make a can, but that wasn't evaluated.

Any thoughts?

bump

I know they wont sell their parts to civilians. Thats what they told me when I asked to buy some COMPAK-16 parts.

Quoted: They also make a can, but that wasn't evaluated.

In an earlier issue of Special Weapons For Military & Police, Al Paulson rated their QD-223 suppressor tied for first place in a three-way tie. The others were the SRT Hurricane and the Advanced Armament M4-2000.

Quoted: I know they wont sell their parts to civilians. Thats what they told me when I asked to buy some COMPAK-16 parts.

You can buy a complete COMPAK-16 upper- The cost is ~$900- Look at the subguns.com NFA parts for sale  board- An ad complete with pictures was there a couple months ago. I posted the link a few months ago on ar15.com but I don't remember it right now..HTH

Yes, the AT LTD weapon is quite real and so is it's slightly larger brother, the 14.0" bbl Recon Rifle (R2).  The company does in fact make the upper receiver available to civilians -- if they currently have a Title II M-16 lower.  Understand, the company is not oriented at all on the civilian market, with the sole excpetion of it's TTR-700 tactical takedown rifle and the even newer TTR-50.  
The principal client list of Arms Tech LTD is the USG and foreign SOF.  I have used a COMPAK-16 for several years in both the progressive gain twist polygonal barrel version and in the earlier cut rifling variants.  The reliability is all that the referenced article claims and more.  Yes, the combination of the gas trap and the special alloy PGTP barrel makes it all happen.  In a recent USG/FMS test in the VA Tidewater area, the weapon went over 24,000 rounds withourt failure and still shot a tad over 1 MOA.  XM-8?  No thanks.
What I really like, in addition to the reliability and accuracy of this weapon is the retained MV of 2,705 fps with M193.  We all know what that translates into.  Have yet to find another short-barreled 5.56mm CQB-oreiented weapon that delivers this MV and the attendant fragmentation of the projectile.  If there is, let me know; I'd sure love to try it.
I haven't had a chance to live fire the QD-223 suppressor, but it's obvviously quite robust Paulson's article certainly stands on it's own merit.  After getting back off of AD in a few weeks I'll be able to play with the suppressor and perhaps post some pics and results.  Might need a little help in posting them here.      

Quoted: Yes, the AT LTD weapon is quite real and so is it's slightly larger brother, the 14.0" bbl Recon Rifle (R2).  The company does in fact make the upper receiver available to civilians -- if they currently have a Title II M-16 lower.  Understand, the company is not oriented at all on the civilian market, with the sole excpetion of it's TTR-700 tactical takedown rifle and the even newer TTR-50.   The principal client list of Arms Tech LTD is the USG and foreign SOF.  I have used a COMPAK-16 for several years in both the progressive gain twist polygonal barrel version and in the earlier cut rifling variants.  The reliability is all that the referenced article claims and more.  Yes, the combination of the gas trap and the special alloy PGTP barrel makes it all happen.  In a recent USG/FMS test in the VA Tidewater area, the weapon went over 24,000 rounds withourt failure and still shot a tad over 1 MOA.  XM-8?  No thanks. What I really like, in addition to the reliability and accuracy of this weapon is the retained MV of 2,705 fps with M193.  We all know what that translates into.  Have yet to find another short-barreled 5.56mm CQB-oreiented weapon that delivers this MV and the attendant fragmentation of the projectile.  If there is, let me know; I'd sure love to try it. I haven't had a chance to live fire the QD-223 suppressor, but it's obvviously quite robust Paulson's article certainly stands on it's own merit.  After getting back off of AD in a few weeks I'll be able to play with the suppressor and perhaps post some pics and results.  Might need a little help in posting them here.

Thanks for the report.  It's nice to hear from someone other than the gun rag author.  

Too bad this isn't being offered OTC to we civie schmucks but maybe some other MFG will adopt some of these features.  What really intrigued me was the claim on their barrel accuracy and service life.  Neither gain twist nor poly rifling are new so I doubt it would be patent protected.  Gas trap innovation sounds cool too, but I wonder if there are simpler solutions which would offer similar functioning.

JMART, actually the gas trap system is a very simple system -- with no moving parts.  Think of it as a big expansion chamber that scavenges excess, unwarranted gas from dumping into the action -- thus lowering pressures and keeping the system very clean and therefore the reliable system that it is.   the scavenging system solves the early timing problem which has plagued virtually all short-barreled direct gas impingement AR/M16-type weapons since day one.  Thus, no need to redesign the bolt, as well.  Nice touch, there.  BTW, civies take heart -- spoke with factory folks the other day and it appears a civilian legal length version may be in the offing in 2005.

Quoted: JMART, actually the gas trap system is a very simple system -- with no moving parts.  Think of it as a big expansion chamber that scavenges excess, unwarranted gas from dumping into the action -- thus lowering pressures and keeping the system very clean and therefore the reliable system that it is.   the scavenging system solves the early timing problem which has plagued virtually all short-barreled direct gas impingement AR/M16-type weapons since day one.  Thus, no need to redesign the bolt, as well.  Nice touch, there.  BTW, civies take heart -- spoke with factory folks the other day and it appears a civilian legal length version may be in the offing in 2005.

That's exactly how the article decsribed it.  It almost sounds too good to be true.  I'm surprised nobody else thought of this before, or maybe someone already did but the concept never really took off.  This system sounds like the cat's meow for M4's and SBR's.  Also, good news that some of this tech may soon come on the market.

One question I have about gain twist rifling -- is it equal in accuracy to conventional rifling?  Conceptually, it seems to me that as the twist rate increases down the bore, the cutting/gripping action on the bullet would result in a skid, or greater jacket deformation than conventional rifling.  I would think that accuracy might degrade with this setup, but maybe it's such a small degradation so as to be essentially meaningless.

Also, do yopu have any knowledge of the special barrel alloy they are using?  I'm assuming it's not 416 SS, but something else, or at least 416 that's treated in some fashion too improve life.  I recall reading years ago in an issue of Precision Shooter about some barrel treatment that when applied to overbore magnums, really improved barrel life quite a bit.  Can't remember the name of the treatment, J-Tex maybe or something like that.  Anyway, that's the only reference I ever saw to such a treatment.  The idea of getting 25K rounds through a barrel and still be sub-2 MOA is incredible.

Frankly, I can't tell you if accuracy from a progressive gain twist polygonal bore is superior to that of cut or Ballard-type rifling.  All I know is that the COMPAK-16's accuracy with the PGT rifling is absolutely nuts...especially after all that GI fodder through it.  I think the real advantages to this materiel are (1) how accuracy is retained after extended use, (2) how MV is retained and (3) how barrel life is enhanced -- at least in the AT LTD weapon.  
BTW, no premature bullet deformation or disruption of the jacket was noticed in the aforementioned USG/FMS testing. The alloy is a special stainless alloy and a highly proprietary one designed specifically for automatic weapons.  No, the barrel has no special treatment such as that you described. For these reasons, I'd sure like to have these guys do up a nice bolt gun with this barrel technology.  A must do when I finally get back home.