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I think I'm building another one...


98Z5V

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"OAL on the brake is 3.438", and max internal threaded depth is 0.850". Even if the 13.5" barrel has a threaded end that's 0.850" long, the brake will still add 2.588" to the barrel length, when permanently attached.  That's a 16.088" overall length.  :thumbup:

That's only a RCH over 16......ATF only uses wooden yardsticks for measuring...sooooo       

   

 

Edited by washguy
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The re-release of the original Primary Arms red dot - it's a direct clone of the Aimpoint Comp M2.  They just updated it and released it again.

http://www.primaryarms.com/pa30mmrd-ad

It's in an Aimpoint QRP mount, but I'll end up mounting it in the Aero Precision 30mm red dot mount.

AP210300_00.jpg

Edited by 98Z5V
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1 hour ago, Robocop1051 said:

I have a CompM2 that just refuses to die. I've had it about 10 years. It got close to dying, sent back to AimPoint and they returned it completely refurbished and looking brand new.... free!

I had my choice in the .mil world - Aimpoint or EOTech.  I always went with the Aimpoint, which was the Comp M2 at the time.  Mounted it as far forward as I could, and ran a PVS-14 behind it as soon as the sun went down. 

Weird how things work, I prefer the EOTech these days.  If Aimpoint would release the 2MOA Comp M2 again, I'd buy one in a heartbeat, though. 

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The only problem with EoTech is the hologram fades in bright sunlight too much.  Even at the highest setting it fades to where it's not functional.  We had them on our M4(s) for the longest but about 6 months before I retired we finally went to the Aimpoints.

I've got the Aimpoint PRO on mine and I have no complaints whatsoever.  Even in the brightest sun you can still se the dot.  If these go on sale again I'll buy another for the AR10.

Edited by GRA
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Try out the PA red dot, man - you can't go wrong at $129 MSRP, and if you don't like it, I will buy it from you at your cost.  No loss on your side, whatsoever.  :thumbup:

I can't tell you if - or not - it will stand up to the long term punishment that my issued Comp M2 would, but I can tell you that PA products really take some punishment. I know my issued Comp M2 lived through many, many aircraft jumps, with shiity landings like a sack of potatoes, and still kept working - worked in Alaska during a Jan-Mar cold weather rotation, and it swam really well.  Lived though an Afghani-Land rotation in some COLD weather at altitudes up to 10,000 feet in the mountains.  Same Aimpoint the whole time.  I can't say if the PA would live through that, or not, and I'm not doing that shiit again just to test one.  :laffs:

However, my only real testament to their quality is this - their mini red dot is tough, as are all their products.  I've been running that mini red dot (Aimpoint T1 clone, in it's original model), on alot of different rifles for alot of years.  Not one has failed.  Not one.  The real deal is the one I specifically bought to see how long it would take to kill it - on the 45-70 gun.  I no kidding only bought that thing to see how long it would last, and document the round count it took to make it's death.  I quit counting the rounds. It's been on there as long as I've had the 45-70, and it just won't die. I think that thing has lived for 3 or 4 years now, under heavy recoil... 

Edited by 98Z5V
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Thank you for the recommendation and information.  For $129.00 I think it's more than worth a try. :thumbup:

I've got a 45-70 also and yes I do believe if it can handle that recoil it can definitely handle the .308 for sure.

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Interesting shiit going on with this barrel. In the Armalite page on this, they say it's 1:8" twist, midlength gas.  Weird twist for a .308 Win barrel, and weird gas tube length for an Armalite AR-10 barrel - why not advertise it as an AR-10 Carbine gas barrel?

Well, you blow up the pics of the barrel in the Armalite page on it, and you can clearly see the barrel markings, and it's 1:10" twist marked right in the barrel material, with the whole marking reads "7.62 AM SS 1:10," which is the 7.62 Armalite Match chamber (not a .308 Win or 7.62 NATO chamber), and stainless steel material, with twist rate.  So, the ad is wrong - typo in the description of the barrel particulars.  It's definitely not 1:8" twist, as the ad says.  Armalite needs to fix that, but, whatever.  If you look closely at the pics, you'll know you're getting 1:10" twist.

Now, that "midlength gas" thing... Second time I've seen this recently.  I saw this on my Wilson Combat .338 Fed barrel, and cautioned a new member about his WC .308 barrel - hope to get pics of that guy's barrel, when the time comes.  Now, I've seen it on this one.

Nathan @ Faxon mentioned this - hybrid kind of gas port location.  Not DPMS-based, not Armalite AR-10-based, but in between.  Either gas tube works, be it Armalite AR-10 Carbine gas tube or AR15 Midlength gas tube. 

I'm not a fan of this.  As we discussed the differences between the two types of BCGs and bolts, it's the proper amount of gas over the proper amount of time, prior to the bolt unlocking and trying to extract the fired casing from the chamber.  We're talking milliseconds here, but hot brass is gonna stick in a tight chamber, until it cools and can be extracted.  Short gas impulse is gonna lead to weak extraction.  Tolerance stacking between manufacturers is gonna screw people over, as we build these things with different parts from different places...

My WC .338 Fed barrel worked fine with the AR15 midlength gas tube. It functioned.  But I didn't like how short it was, and at that point, I'd only fired factory Federal ammo, the 200gr Fed Fusion soft points.  How would it work with other ammo? Don't know, cause the damn .338 Fed loaded ammo is hard to find.  How will it work with my handloads? Don't know yet, because I'm not loading it yet.  So, I switched out the gas tube with an Armalite AR-10 Carbine gas tube, which went about 2/3rds of the way back the cam pin cut out in the upper...  Zero interference with the gas key on the carrier, it's not bottoming out...  Longer gas impulse over a longer time will be a more reliable gas operating system.

So, in a nutshell, Armalite has done it now.  This 13.5" 3-Gun barrel isn't AR-15 midlength, or the gas tube would be dead-smack in the middle of the cam pin cut out.  It's about 1/3rd of the way back the cam pin cut out - same as my WC .338 Fed barrel was.  I'm going to run it with this AR15 Midlength gas tube, and see how it does, but I'm ordering another Armalite AR-10 Carbine gas tube, which IS going to put the end of the gas tube about 2/3rds of the way back in the cam pin cut out.

This weird barrel gas port poop is aggravating - but it's becoming more prevalent.  Wilson Combat is doing it, at least on the .338 Fed barrels, Faxon is doing it on their .308 Win barrels, and now even Armalite is doing it on some of their barrels...

Something to watch for, and something else to look at, when we get weird "weapons operations problems" asked...

Here's the AR15 midlength tube in the upper, on this 13.5" Armalite barrel...

 

 

P1050684.JPG

Edited by 98Z5V
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27 minutes ago, 98Z5V said:

Here's the AR15 midlength tube in the upper, on this 13.5" Armalite barrel...

P1050684.JPG

OK so if I follow you right, the Armalite "carbine" gas tube should extend further in to the gas key than this gas tube in the photo, correct?

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AR15 Midlength gas tubes are 11 3/4" long.  AR-10 Carbine length gas tube is 12 1/16" long.

Armalite AR-10 rifle gas tubes are equally as much longer than AR15 rifle gas tubes. 

The AR-10 uses a longer gas system, with only two gas tube lengths - "Carbine" is 12 1/16" gas tube, and "RIfle" is 15 1/2" gas tube.  Those numbers don't match any AR15-lengthed gas tubes.

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34 minutes ago, GRA said:

OK so if I follow you right, the Armalite "carbine" gas tube should extend further in to the gas key than this gas tube in the photo, correct?

Yes, it will. 

Here's what my Wilson Combat .338 Fed barrel looked like - it's midlength gas, according to Wilson Combat, but in reality, it's not. It's in between AR15 Midlength and AR-10 Carbine length.  First pic is AR15 midlength tube, second pic is the AR-10 Carbine gas tube.

WC 338 Barrel, AR15 midlength gastube.jpg

WC 338 Barrel, Armalite AR-10 Carbine gastube.jpg

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35 minutes ago, 98Z5V said:

Yes, it will. 

Here's what my Wilson Combat .338 Fed barrel looked like - it's midlength gas, according to Wilson Combat, but in reality, it's not. It's in between AR15 Midlength and AR-10 Carbine length.  First pic is AR15 midlength tube, second pic is the AR-10 Carbine gas tube.

WC 338 Barrel, AR15 midlength gastube.jpg

WC 338 Barrel, Armalite AR-10 Carbine gastube.jpg

Yes, thank you this is what I was asking about.  The difference is more than clear.

Seems like the loner tube would give you a better gas seal and would be 100% functional as such as long as it didn't get bashed by the gas key / bottom-out.

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26 minutes ago, GRA said:

Yes, thank you this is what I was asking about.  The difference is more than clear.

Seems like the loner tube would give you a better gas seal and would be 100% functional as such as long as it didn't get bashed by the gas key / bottom-out.

On a DPMS-based rifle, as my .338 is, that longer gas tube doesn't bottom out on the DWilson BCG's gas key - it's fine.  I think the differences we noted on the AR-10 vs. DPMS-based BCGs shows that the AR-10 gas key sits further away from the front of the BCG body, so the AR-10 gas key sits back more than a DPMS gas key does.  I think the AR-10 BCG will be just fine with the longer gas tube.  I don't think the AR-10 BCG will have enough overlap (gas key covering gas tube) on the shorter AR15 midlength gas tube.  Short-Stroke City, is what I think.  I'll shoot it like this and find out.

I won't know for sure until I get my AR-10 BCG...

Shiit like this is the very reason that I hate everyone calling a .308AR a damn "AR-10." There ARE differences.  Those differences screw us all up here, trying to find solutions for problems that shouldn't exist, if the nomenclature was correct...  I literally see posts now, and just turn away - click on something else.  Drives me nuts...

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7 minutes ago, 98Z5V said:

Shiit like this is the very reason that I hate everyone calling a .308AR a damn "AR-10." There ARE differences.  Those differences screw us all up here, trying to find solutions for problems that shouldn't exist, if the nomenclature was correct...  I literally see posts now, and just turn away - click on something else.  Drives me nuts...

Yes I do agree with you that this has been problematic and frustrating.  Especially with a newcomer like me to the AR-10 / LR-308 scene.

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  The 1-8 twist description was taken about in a thread quite a while ago & we all said is wasn't right & the poster called Armalite & they said it was misprint , that they were all 1-10 twist .

   Its seems the nomenclature is being made worse by manufacturers ( Barrels ) changing the normal designation or the actual Gas Port location on Barrels , remember Futon Armory changed their Barrels Gas port to Armalite spec's & say to use an Armalite length Gas Tube now a days . I have two Kreiger Criterion Barrels from them & the Gas tube locations are AR 15 Rile length , so its just not saying what it is now , they are changing DPMS  to AR 10 , so the designation is correct , its just not being used on an AR 10 , but a DPMS .  Confusing this situation even more , you don't know what component is required till you start to build .

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3 minutes ago, survivalshop said:

  The 1-8 twist description was taken about in a thread quite a while ago & we all said is wasn't right & the poster called Armalite & they said it was misprint , that they were all 1-10 twist .

Can't believe they haven't fixed that yet, it was the end of February when they told me it was a typo and they would get it fixed right away..........

feel like ordering one then raising hell about not getting what they described.

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4 minutes ago, survivalshop said:

  The 1-8 twist description was taken about in a thread quite a while ago & we all said is wasn't right & the poster called Armalite & they said it was misprint , that they were all 1-10 twist .

You'd think they'd change the product description, by now.  I almost didn't order the barrel, based on the 1:8" twist description.  Hell do I need a 13.5" barrel in 1:8 twist for?  Only shoot 220gr projos from it?...  Once I blew the pics up, and saw 1:10, I bought it. 

Shiit, I almost committed to it, before I blew the pics up. Said, "Self... you're gonna have to load only 220s for this thing..." 

"Self" is what I call myself...  :laffs:

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This is what they look like when the gas tube is too short - this is the result of ONE combination - this is an Armalite (longer) gas port position in the barrel, combined with a DPMS-based gas tube (standard AR15 gas tube).  The end of the gas tube barely even reaches the opening of the cam pin cut out.

IMG_0343.JPG

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