With all due respect to those who posted in the MA-TEN thead, the barrel discusson has been lost in the mix, so I figured I'd ask questions in a thread specific to the barrrel.

I just plced an oder for a Kaiser 16" barrel from Rainier.  I like that the Kaser barrel is a mid-length gas barrel, as oppose to the DPMS A4 barrel which is a carbine gas barrel.  The two are approxmately the same price, but I wanted to try te Kaiser.  I intend to use a DPMS BCG, so I'd want Rainier to install a DPMS extension on the barrel.  The DPMS barrel appears to be a good barrel from the AP4 owner feedback I'e found on the internet, but I haven't been able to find any feedback on the Kaiser barrels.

How well did the DMPS extension and barrel work out in a MA-TEN?  

Any range reports with the Kaiser barrel (16" or 18")?

I wanted to know about Kaiser barrels when I built my ma/ten never heard any feedback so I bought the RA 16" Ultramatch I'm very happy with it. Please post info when you shoot the Kaiser barrel.

Anyone?  No one has shot their Kaiser barreled rifle yet?

I've got one in the mail to me. Should have it tested by the end of the week. What information are you guys looking for?

Just would like to know the barrel performed, e.g. what kind of precision at the range.  Did you get an 18" or 16" Kaiser barrel?

I expect the accuracy to be similar from both the 18" and 16" barrels up to a limited range.  So gettings some samples of both would be nice.  I don't need 500+ yards performance from this build but I sure would like to know if I need to hit a dinner plate 300 yards out with a 16", it's going to do it.

I placed an order with the guys at Rainer, and I have to send my BCG to them so they can headspace the extension to the BCG. Would have just bought the DPMS BCG from Rainer, but they are out, so I'm going to send the one I bought more locally.  Rainer has had good feed back from customers, but I don't have specifics.

Fitmet tot he MA-TEN doesn't appear to be an issue, not that Ive found a couple of threads in which guys use the Kaiser barrel.

I have heard people using the DPMS BCG with the Kaiser barrels.  When I called Kaiser directly, they said they recommend using Armalite as the AR dimensions are more conducive to their barrel extension specs.  Why are folks using DPMS?  I am still leaning toward a Kaiser barrel but have held off due to a lack of information.  The only other ferritic nitrocarburized barrel for .308 AR's out there is made by LWRC, but they don't sell them separately.

I'm using the DPMS BCG because I hear the Armalite extension is a little too tight in the MA-TEN. There were a few guys in the MA-TEN thread that posted about this which required them to heat/cool the parts and then need some force to make the extension fully seat in the receiver.  I also went DPMS because I feel this is the more popular system...and ultimately more available parts (availability and $) for later replacement, etc.  I could be wrong, but unless there is something truely technically wrong with a DPMS extension on a Kaiser barrel, I see no drawback.  

Tight is not a bad thing. Especially on a heavier 308 setup.
Wish my 556 guns were as tight as my MATEN/Noveske setup.

I would agree that better tolerances is a good thing; however, what has been reported of the Armalite extensions is what I'd call out of spec...in those cases.  Additionally, no one has reported a DPMS extension being loose. The barrel nut should tighten up the extension against the receiver once the extension is seated and the barrel nut properly torqued. So I'm not sure you are gaining anything with an overly large (or tight) extension.

There seems to be some conflicting information on the Kaiser barrel over the length of the the gas system.  Do the Kaiser 16" and 18" have the Armalite "carbine" gas system (=slightly longer than the AR15 mid-length) or do they have the standard AR15 mid-length gas system?  

Anyone have a Kaiser barrel on hand to measure the distance to the gas port or know for certain that they ordered a particular gas tube (AR15 mid-length or Armalite carbine) and it worked?

Thanks John. UPS should deliver my order today. Can't wait to get the rifle together! You guys were great to work with.

That doesn't make sense.  The Kaiser barrels do not come with a barrel extension option; they are Kaiser extensions.  The MA-TEN is designed to work with either a DPMS or Armalite bolt.  The question with the Kaiser barrel is which one should be used.  I have heard either will work as long as it headspaces properly, but when I called Kaiser directly, they recommended the Armalite bolt because dimensionally it is stronger and fits better with their barrel extension.

My original question is why are people going with DPMS bolts with the Kaiser barrel.  I assumed they knew something I didn't.  Again, since the Kaiser barrel uses neither a DPMS or Armalite barrel extension, the fact that DPMS extensions fit tight is irrelevant.

Not sure why it doesn't make sense. Unless the Kaiser barrel has unique threading, either a DMPS or Armalite barrel extension should thread onto it.  As you said either extension can be used as requested and headspaced (and pinned).  I assume this is what Rainier is doing based on the order placed by their customers.   Perhaps John can shed some light on the subject.

The issues folks have encountered is the Armalite extension OD being slightly larger than the DMPS extension OD. With the coating on the MA-TEN, the Armalite extension is a very tight fit.  No one has claimed the DPMS being loose in the receiver.

With either extension, the flange of the extension rests on the receiver and the barrel nut tightens up the extension onto the receiver. So it's not like the DPMS extension on the Kaiser barrel results in the barrel flopping around on the reciever.  

So the remaining issue is the gas port location and gas tube length, which Kaiser drills for an Armalite "carbine" length gastube, which is actually slightly longer than a standard AR15 mid-length. So the only real difference is the location of the gas port. So how can Kaiser state that the barrel works better with an Armalite extension?

As for why folks are going with a DPMS bolt..in my case, I assumed the DPMS bolt is the more popular bolt, thus there will be more available parts (replacement availability and cost advantage).


To clarify, my prior post. the Armalite bolt and DPMS bolt faces are different, so I assumed Rainier buys barrels from Kaiser without an extension. Then when an order is placed, Rainier installs either a DPMS or Armalite extension per customer request.

gixxerman has posted a range report here: (looks good)


gixxerman's thread

So you order barrels with DPMS extensions and barrels with Armalite extensions for inventory. I was wondering how the extension and gas port clocking would work out if Kaiser didn't install the extensions prior to drilling the gas port.

As I tried to explain in my post, Kaiser uses their own proprietary extension.  The question is whether to use a DPMS bolt or Armalite bolt.  I have heard from Kaiser that the Armalite bolt works best, and have heard from others here to use DPMS.  My question to those using DPMS bolts was why?  You said because Armalite extensions fit tight.  Again, Kaiser does not use an Armalite extension, and since my question was which bolt works best with their proprietary extension, your answer makes no sense.  Based on your assumption above, I can see why you thought it did make sense.  Given that the reality of the situation is that the Kaiser barrels are sold with their own extensions, and Rainier obviously has no plans to fit them with Armalite or DPMS extensions, we are back to my original question.  Why the DPMS bolt?  Basing a reply on Rainier hypothetically changing the extensions doesn't work, because we are dealing with what is actually out there, not supposition.

I am confused even more now. How come your website lists both Kaiser barrels as Mid length? Also, here is a quote from an email from Rainier: "The KMT use a DPMS pattern for the gas systems. The DPMS pattern is basedoff of the standard AR15 gas system."