Warning

 

Close
Confirm Action

Are you sure you wish to do this?

Cancel Confirm
AR15.COM
6/12/2017 7:50:32 PM EDT
Hi Nathan,

My 14-1/2" Gunner Barrel with the pinned and welded Flash Hider arrived today from AIM Surplus.  As an added bonus it came with a Gas Block already drilled for a pin.  It is already attached to the barrel with two set screws.  I asked the folks at AIM how accurate was the gas block alligned before the drilled the hole for the pin.  Their reply, was it was drilled by Faxon, not them.  I inquired I didn't see any drilled gas blocks on the Faxon website, and their answer was they get some special things from Faxon not on the website, since they are just down the road from you.

My question is, do I need to be concerned in any way about the alignment of the gas block on my barrel?  Do I need to measure and check things out when I remove the gas block to install my barrel nut?  Or is everything good to go?

I now have a new Faxon gas block I ordered from you that I don't need.

Thanks,  

Rick
6/12/2017 8:01:23 PM EDT
[#1]
Nathan, the reason I am asking this question is the gas block is canted to the left (looking toward the muzzle) about  3 degrees from vertical.  Is the hole in the block large enough to allow for this much misalignment?

Sorryu I forgot to add this tidbit in my original post.

Rick
6/12/2017 9:30:49 PM EDT
[#2]
Not answering for Nathan. Most (all I've seen) gas blocks (or A2 FSB) ports are larger than the barrel gas port to allow for inconsistencies. I wouldn't be too concerned unless you're having malfunctions.

As for the pinned and set screws: Faxon does this special for AIM. Personally I prefer this and thank Faxon and AIM for doing that.
6/12/2017 11:43:06 PM EDT
[#3]
Op

I just bought the exact same barrel. I aligned it and tightened down the screws and Put the pin in.  I got the pin in most of the way but it should've been easier in my opinion. It seems that it was drilled a little crooked to me as well. Doing this, I had it aligned properly and not with a cant.

When I tried to use the pin without tightening the set screws first, the block was crooked. Looking at the drill Mark with the gas block removed, it sure looked like it wasn't straight across the bottom. I was going to call aim but pulled it back apart this evening and did what I said above. With the set screws tight and the pin most of the way in, I'm sure it'll operate just fine.
6/13/2017 7:55:09 AM EDT
[#4]
Quote History
Quoted:
Nathan, the reason I am asking this question is the gas block is canted to the left (looking toward the muzzle) about  3 degrees from vertical.  Is the hole in the block large enough to allow for this much misalignment?

Sorryu I forgot to add this tidbit in my original post.

Rick
View Quote
The physical machining operation is aligned off of the extension which is what sets the gas port, etc. We then use a roll pin specifically to allow for minor variance and for crushing to get perfect alignment, if needed.

On the gas block, the hole is .125". It is specifically designed to be able to handle any minor cant if present.
6/13/2017 3:56:39 PM EDT
[#5]
I believe at this time, there is no cause for alarm.  I think the gas block was put on the barrel and the set screws were just to hold it sort of in place.  I took a bunch of drill rods and started with one that would go thru the slot in the barrel with the gas block in the location it was in when i received it.  Then I loosened the set screws and progressively inserted larger and larger drill rods until the fit in the slot was fairly tight.  The gas block was considerably straighter than when I started.  It appears there was no attempt to align the gas block perfectly with just the set screws.  

I think when I get the barrel installed and the gas block properly pinned and tightened it will be OK.  Thanks you all for your help.  If I notice any problems at that time I will further address the issue.

I have one more question, there were no instructions with the barrel as to assembly.  There are many you tube videos so I am not too worried, but what is the recommended torgue from Faxon for the barrel nut?

Thank you
6/13/2017 3:59:36 PM EDT
[#6]
Quote History
Quoted:
I believe at this time, there is no cause for alarm.  I think the gas block was put on the barrel and the set screws were just to hold it sort of in place.  I took a bunch of drill rods and started with one that would go thru the slot in the barrel with the gas block in the location it was in when i received it.  Then I loosened the set screws and progressively inserted larger and larger drill rods until the fit in the slot was fairly tight.  The gas block was considerably straighter than when I started.  It appears there was no attempt to align the gas block perfectly with just the set screws.  

I think when I get the barrel installed and the gas block properly pinned and tightened it will be OK.  Thanks you all for your help.  If I notice any problems at that time I will further address the issue.

I have one more question, there were no instructions with the barrel as to assembly.  There are many you tube videos so I am not too worried, but what is the recommended torgue from Faxon for the barrel nut?

Thank you
View Quote
35-40 Ft/lbs
6/14/2017 2:45:58 PM EDT
[#7]
Quote History
Quoted:
Op

I just bought the exact same barrel. I aligned it and tightened down the screws and Put the pin in.  I got the pin in most of the way but it should've been easier in my opinion. It seems that it was drilled a little crooked to me as well. Doing this, I had it aligned properly and not with a cant.

When I tried to use the pin without tightening the set screws first, the block was crooked. Looking at the drill Mark with the gas block removed, it sure looked like it wasn't straight across the bottom. I was going to call aim but pulled it back apart this evening and did what I said above. With the set screws tight and the pin most of the way in, I'm sure it'll operate just fine.
View Quote
Well I installed the gas block and experienced the exact same issue.  I could not get the pin completely in the slot under any circumstances.  I was able to get the pin in partially, then tightened the set screws.  Hopefully it will work, but it is at a slight cant, maybe 1-1/2 to 2 degrees.  I did notice the hole in the gas block is quite a bit larger than the hole in the barrel, so hopefully it will work.  It will be a couple of weeks until I get my lower completed, but when I shoot the gun, if I have any problems with cycling, the upper will go to Faxon.  I kinda farkled up the barrel nut, so the complete upper will need to be sent back if necessary.  I'm not a gunsmith, primarily a shooter.
6/14/2017 4:43:14 PM EDT
[#8]
Quote History
Quoted:



Well I installed the gas block and experienced the exact same issue.  I could not get the pin completely in the slot under any circumstances.  I was able to get the pin in partially, then tightened the set screws.  Hopefully it will work, but it is at a slight cant, maybe 1-1/2 to 2 degrees.  I did notice the hole in the gas block is quite a bit larger than the hole in the barrel, so hopefully it will work.  It will be a couple of weeks until I get my lower completed, but when I shoot the gun, if I have any problems with cycling, the upper will go to Faxon.  I kinda farkled up the barrel nut, so the complete upper will need to be sent back if necessary.  I'm not a gunsmith, primarily a shooter.
View Quote
I actually locked down the set screws first the put the pin in the best I could.  It's pretty much straight.  I'll try to get a couple pics later.
6/19/2017 11:10:01 AM EDT
[#9]
The gas blocks on both of my Faxon barrels are slightly canted to the right but both guns function 100%. The pin on the 16" barrel was a bear to get driven in all the way but I was able to get it done. I don't remember having any trouble with the 20" barrel from a couple months ago. I left the set screws loose until the pin was in since the pin is the main source of locking down then I tightened the set screws.

The roll pins are slightly oversized and are designed to compress so they hold tight and since they are not tapered you are fighting resistance the entire way.
6/19/2017 4:23:49 PM EDT
[#10]
I'm encouraged to hear your results were positive.  I absolutely could not get the pin all the way in.  It is just too big for the hole.  But I did get in partially and tightened the set screws.  I am encouraged to hear you had 100% function with yours, so I am hoping for the same, even though the gas block is slightly tilted.  With it being under the rail, I could care less as long as it works.


Thanks,

Rick
6/19/2017 11:51:38 PM EDT
[#11]
Quote History
Quoted:



Well I installed the gas block and experienced the exact same issue.  I could not get the pin completely in the slot under any circumstances.  I was able to get the pin in partially, then tightened the set screws.  Hopefully it will work, but it is at a slight cant, maybe 1-1/2 to 2 degrees.  I did notice the hole in the gas block is quite a bit larger than the hole in the barrel, so hopefully it will work.  It will be a couple of weeks until I get my lower completed, but when I shoot the gun, if I have any problems with cycling, the upper will go to Faxon.  I kinda farkled up the barrel nut, so the complete upper will need to be sent back if necessary.  I'm not a gunsmith, primarily a shooter.
View Quote
Same as with removing/re installing any other pinned gas block. You slide the block in place, line up the "pin" holes, then drop a drill bit (usually 1/8") in there to hold it as you tighten the set screws up. Always line the hole up first (drill bit trick) BEFORE tightening the set screws. You pin it in place, then loosen and retighten the set screws to make sure nothing is "fighting" itself with alignment.
7/3/2017 7:08:13 PM EDT
[#12]
Hello Nathan,

First range trip with new AR with your barrel 14-1/2 pinned. Even tho the gas block is canted it seemed to work well. Every time last round fired the bolt held open like it should.  I am using a Damage Industries Chrome Slicone recoil spring, which it turns out is about 1/2"to 3/4" shorter than the standard carbine mil-spec spring I had. I fired Pmags USGI and Lancer mags, all no problem.  The shell casings were ejecting at about 2:30 and about 3 to 4 feet.  I changed the buffer from standard to H and the casings moved back to 3:00, only they weren't ejecting with the same force, more like 2-1/2 feet.

The last mag I fired I rapid fired and the last round jammed with the bolt pinning the side of the shell.  I'm thinking I should go back to the standard carbine buffer.   What do you think? Do you think the gas block being canted is the problem?  Am I overthinking this and maybe the barrel and the rifle (all new) isn't broken in yet?  I put about 100 rounds thru it today.

Hopefully I won't need to send the barrel back to you guys, that is a real hassle.  Let me know your thoughts.

Thank you,

Rick
7/4/2017 11:15:57 PM EDT
[#13]
Quote History
Quoted:
Hello Nathan,

First range trip with new AR with your barrel 14-1/2 pinned. Even tho the gas block is canted it seemed to work well. Every time last round fired the bolt held open like it should.  I am using a Damage Industries Chrome Slicone recoil spring, which it turns out is about 1/2"to 3/4" shorter than the standard carbine mil-spec spring I had. I fired Pmags USGI and Lancer mags, all no problem.  The shell casings were ejecting at about 2:30 and about 3 to 4 feet.  I changed the buffer from standard to H and the casings moved back to 3:00, only they weren't ejecting with the same force, more like 2-1/2 feet.

The last mag I fired I rapid fired and the last round jammed with the bolt pinning the side of the shell.  I'm thinking I should go back to the standard carbine buffer.   What do you think? Do you think the gas block being canted is the problem?  Am I overthinking this and maybe the barrel and the rifle (all new) isn't broken in yet?  I put about 100 rounds thru it today.

Hopefully I won't need to send the barrel back to you guys, that is a real hassle.  Let me know your thoughts.

Thank you,

Rick
View Quote
If that 14.5" is a middy, I'd stay with a carbine (2.8-3oz) buffer. H usually works great for 16" middy's, but not 14.5.
7/5/2017 6:50:21 PM EDT
[#14]
It is a middy.  I haven't tried rapid fire with the carbine buffer, just slow fire and had the above results.  It'll be a couple of weeks until I can try it again.  I'm still very interested in Nathan's opinions.

Should I look at one of the Vltor super light buffers?  I think they require special springs tho.

Rick
7/6/2017 7:59:53 AM EDT
[#15]
Quote History
Quoted:
Hello Nathan,

First range trip with new AR with your barrel 14-1/2 pinned. Even tho the gas block is canted it seemed to work well. Every time last round fired the bolt held open like it should.  I am using a Damage Industries Chrome Slicone recoil spring, which it turns out is about 1/2"to 3/4" shorter than the standard carbine mil-spec spring I had. I fired Pmags USGI and Lancer mags, all no problem.  The shell casings were ejecting at about 2:30 and about 3 to 4 feet.  I changed the buffer from standard to H and the casings moved back to 3:00, only they weren't ejecting with the same force, more like 2-1/2 feet.

The last mag I fired I rapid fired and the last round jammed with the bolt pinning the side of the shell.  I'm thinking I should go back to the standard carbine buffer.   What do you think? Do you think the gas block being canted is the problem?  Am I overthinking this and maybe the barrel and the rifle (all new) isn't broken in yet?  I put about 100 rounds thru it today.

Hopefully I won't need to send the barrel back to you guys, that is a real hassle.  Let me know your thoughts.

Thank you,

Rick
View Quote
The distance of ejection is due to the ejector spring. 2-3 feet is NOT normal for an AR-15 and that should be replaced.

Yes, drop back to normal carbine, shoot, and enjoy!