Modernizing the A2 style AR15

DMK · November 1, 2017, 08:59 AM

My only 20" AR15s I currently have are an A1 type and an A2 type, both with fixed carry handles. I was thinking a while back that it would be nice to mount a light and RDS to one of these for HD use taking advantage of the added velocity of the longer barrel. The 1/7 twist A2 makes the most sense since it will handle mk262 77gr OTM vs the 1/12 twist on the lighter A1.

Nothing wrong with irons and I still have them available, but I wanted the advantages of a red dot too. So here's what I did:

Gooseneck Aimpoint Mount. I got this really cheap on Ebay. You can also find them on the AR15.com EE or gun shows.

Handguard mounted light rail. The only permanent modification since you have to drill holes in the handguard, but I have a spare handguard so not that permanent.

LED light mounted about 2:00

Primary Arms Micro on an American Defense QD mount. Absolute cowitness with irons if the dot dies. Quickly removable if the glass shatters. Added capability with no real downside.

smee78 · November 1, 2017, 01:24 PM

Interesting, I havent seen an optic mount like that before.

DMK · November 1, 2017, 02:01 PM

It's an inexpensive Aimpoint Gooseneck

There are a bunch on Ebay, plus various other sources
https://www.ebay.com/sch/i.html?_fro...seneck&_sop=15

Sharkbite · November 1, 2017, 02:32 PM

I put a Trijicon Reflex on an AR back in the day with that same set up. Works ok. The newer flat top uppers make for a nicer set up, but that will work!!

turtlehead · November 1, 2017, 09:15 PM

That sure is better than mounting something on top of the handle. Very cool. How is the field of view?

DMK · November 2, 2017, 06:38 AM

Quote:

That sure is better than mounting something on top of the handle. Very cool. How is the field of view?

It's much better than top mounting it. With the gooseneck, the ergonomics are the same as using the iron sights. It's absolute cowitness.

FOV isn't optimal looking through the sights and RDS, but with both eyes open and focusing on the target (like you should be doing with a red dot), I can see everything I need to see. It is very usable and effective.

USMCGrunt · November 2, 2017, 09:14 AM

I never cared for the goose neck mounts. I have one that came with my old Aimpoint M68 (or whatever the civilian designation for that sight is) and tried it one time. The slightest pressure on that mount will deflect the point of impact way off.

DMK · November 2, 2017, 11:05 AM

Quote:

The slightest pressure on that mount will deflect the point of impact way off.

That makes sense with the optic being out on the end of a longish lever.

I'll keep this limitation in mind.

MagnumWill · November 19, 2017, 10:05 AM

Grrr! Every time I try to talk myself out of an A2 Build, something like this happens

That’s a great setup. That was my biggest concern with an a2 upper is I could never stomach how high the optic is off of the bore. The gooseneck is an elegant solution. I understand you could get the lever arm effect to a certain degree but I don’t think it would be easy to inadvertently put pressure on it while shooting.

DMK · November 20, 2017, 07:28 AM

Quote:

Originally Posted by MagnumWill

Grrr! Every time I try to talk myself out of an A2 Build, something like this happens

I know. This is how we end up with a dozen AR15s of various configurations in the gun safe. They are fun to build though.

Quote:

Originally Posted by MagnumWill

That’s a great setup. That was my biggest concern with an a2 upper is I could never stomach how high the optic is off of the bore. The gooseneck is an elegant solution. I understand you could get the lever arm effect to a certain degree but I don’t think it would be easy to inadvertently put pressure on it while shooting.

I agree. This mount puts the optic at the same height as it would be with a flat top receiver. When I saw these relatively cheap on Ebay, I had to try one.

You may also note that Aimpoint includes a clamp that attaches to the front of the carry handle to minimize deflection. (Perhaps this was was not included in the earlier versions of this mount.)

November 1, 2017, 08:59 AM	#1
DMK Senior Member Join Date: November 18, 2001 Location: Over the hills and far, far away Posts: 3,206	Modernizing the A2 style AR15 My only 20" AR15s I currently have are an A1 type and an A2 type, both with fixed carry handles. I was thinking a while back that it would be nice to mount a light and RDS to one of these for HD use taking advantage of the added velocity of the longer barrel. The 1/7 twist A2 makes the most sense since it will handle mk262 77gr OTM vs the 1/12 twist on the lighter A1. Nothing wrong with irons and I still have them available, but I wanted the advantages of a red dot too. So here's what I did: Gooseneck Aimpoint Mount. I got this really cheap on Ebay. You can also find them on the AR15.com EE or gun shows. Handguard mounted light rail. The only permanent modification since you have to drill holes in the handguard, but I have a spare handguard so not that permanent. LED light mounted about 2:00 Primary Arms Micro on an American Defense QD mount. Absolute cowitness with irons if the dot dies. Quickly removable if the glass shatters. Added capability with no real downside. __________________ - Homeland Security begins at home: Support your Second Amendment - www.gunowners.org - www.saf.org - act.nraila.org - www.grnc.org Last edited by DMK; November 1, 2017 at 09:05 AM.

November 1, 2017, 01:24 PM	#2
smee78 Senior Member Join Date: July 14, 2008 Location: South Carolina Posts: 2,918	Interesting, I havent seen an optic mount like that before. __________________ We know exactly where one cow with Mad-cow-disease is located, among the millions and millions of cows in America, but we haven't got a clue where thousands of illegal immigrants and terrorists are

November 1, 2017, 02:01 PM	#3
DMK Senior Member Join Date: November 18, 2001 Location: Over the hills and far, far away Posts: 3,206	It's an inexpensive Aimpoint Gooseneck There are a bunch on Ebay, plus various other sources https://www.ebay.com/sch/i.html?_fro...seneck&_sop=15 __________________ - Homeland Security begins at home: Support your Second Amendment - www.gunowners.org - www.saf.org - act.nraila.org - www.grnc.org

November 19, 2017, 10:05 AM	#9
MagnumWill Senior Member Join Date: March 18, 2009 Location: Central Colorado Posts: 1,001	Grrr! Every time I try to talk myself out of an A2 Build, something like this happens That’s a great setup. That was my biggest concern with an a2 upper is I could never stomach how high the optic is off of the bore. The gooseneck is an elegant solution. I understand you could get the lever arm effect to a certain degree but I don’t think it would be easy to inadvertently put pressure on it while shooting. __________________ Those who hammer their swords into plow shares will plow for those who didn't...

November 1, 2017, 02:32 PM	#4
Sharkbite Senior Member Join Date: November 4, 2013 Location: Western slope of Colorado Posts: 3,679	I put a Trijicon Reflex on an AR back in the day with that same set up. Works ok. The newer flat top uppers make for a nicer set up, but that will work!!

November 1, 2017, 09:15 PM	#5
turtlehead Senior Member Join Date: October 20, 2015 Location: Phoenix, AZ Posts: 1,203	That sure is better than mounting something on top of the handle. Very cool. How is the field of view?

November 2, 2017, 09:14 AM	#7
USMCGrunt Senior Member Join Date: February 27, 2000 Location: Somewhere in 14T NT Posts: 730	I never cared for the goose neck mounts. I have one that came with my old Aimpoint M68 (or whatever the civilian designation for that sight is) and tried it one time. The slightest pressure on that mount will deflect the point of impact way off.