Results 1 to 9 of 9

Thread: 20-inch overhaul

  1. #1
    Join Date
    Oct 2008
    Location
    Maine
    Posts
    2,113
    Feedback Score
    3 (100%)

    20-inch overhaul

    I posted pics of this elsewhere on the forum but since I’m at work with not much to do I figured I’d finally do a write up on it.

    So firstly, this is less of a “build” and more of a “renovation” of an existing gun.
    For a while now I had been interested in the concept of pairing a 20” barreled upper with an adjustable stock lower in the vein of the Canadian C7A2 and the “M16A5” concept.
    I like 20” ARs a lot but my current 20”s all have fixed stocks and I wanted to at least give an adjustable-stock 20” a try.
    Finally I decided to go ahead and convert one of my other guns (A 16” midlength with fixed stock actually) to this configuration. So I procured a BCM 20” upper and made the changes I wanted to make to the lower. Here is the result:







    Lower receiver is just a regular Aero, FCG is an ALG ACT. Safety selector is the Seekins 60/90 ambi model. I just have it setup for the standard 90degree throw. I like ambi safeties but I don’t think I’m going to buy any more Seekins ones as the right side lever jabs the shit out of my firing hand unless I file it down slightly, which you might be able to discern in the pics. This is something I eventually resorted to on the ones I already had but don’t intend to get more now knowing I’ll have to do this.

    The Vltor A5 system which was designed for the aforementioned “M16A5” concept would have been a good option but I ended up going with something more akin to what the Canadians do with their C7A2s. I used a standard BCM carbine RE, a Sprinco “White” spring and an H3 weight buffer (the Canadians use an H2 equivalent called an “HH”) mostly because I already had the stuff on hand.
    I used an LWRC compact stock. It is of similar dimensions to the CAR style stock that the Canadians use, with some improvements in terms of cheekweld. I have multiple LWRCs and actual CAR stocks, so I guess I like a lower profile stock in most cases. In fact the LWRC in the pics is actually one I pulled off one of my SBRs while I was waiting for another one to be delivered.
    I’ve taken a liking to the Griffin Armament A3 pistol grips of late and also use them on a few other guns. Similar dimensions to an A1/A2 grip but with a reduced angle.

    Upper is a BCM 20” rifle upper. The charging handle, Mbus Pro rear sight and BCM bolt carrier were all transferred over from the previous upper, although the bolt *itself* is a new SOLGW.

    Handguard is a Midwest Industries drop in rifle-length Mlok rail, with a couple of Israeli handguard bands over about two-thirds of it because I really only use the attachment points at the very front. It feels a little dumb to buy a $100 handguard just to cover most of it up but I’m not crazy about how “chunky” Magpul MOEs are. So the Midwest was the only other option I knew of for a *drop in* Rifle-length Mlok setup, however although they are sufficiently slim, they have a rather uncomfortable angular shape when left bare, so I simply covered up the area I was unlikely to attach anything to.
    I added a Magpul mounting point on the left side although this is probably not a gun that is going to habitually wear a light. However having the ability to slap one on if needed is nice.

    The optic is a Trijicon TA-110 LED 3.5x ACOG with the crosshair reticle.







    At first my plan was that I was going to just put my Primary Arms 3X prism on it but the reason why I didn’t is kind of a long story, suffice to say I opted to get something else. Originally that was going to be a Steiner T332 3X prism, which I actually did order. However not long after I ended up just saying “F*** it, I’m buying an ACOG” and cancelled my order for the Steiner.

    I went with the 3.5x TA-11 with dual illumination and a green chevron reticle. I had never tried a green reticle in anything before but it was on sale at Midway. When I received the optic however I found that I kind of hated the green, plus the dual illumination did not play well with my eyes. I perceived the chevron as blurry. Even covering up the tube to dim the illumination didn’t seem to make much difference with regard to the crispness of the reticle. Plus, and most glaringly, there was a factory defect on the ocular lens so it immediately went back to Midway for a refund.
    In the meantime, I again ordered a Steiner T332….and again a short time later I again cancelled the order when I found out that the battery powered LED ACOGs existed.
    The idea of being able to turn the illumination off completely for better precision when zeroing or whatever appealed to me. So that’s how I ended up with the TA-110. This time I opted for the the crosshair reticle, with red illumination, which as it turns out I quite like. The manual brightness control is much more to my preference as well.
    In using it at close range (like 20yards and in) the ACOG is definitely slower and clumsier than an Aimpoint but it is still acceptably usable (and will probably become more so with further practice) but I may still stick an RMR on it at some point. Like the guns I’ve used the PA prisms on in the past, this gun is intended as an “outdoor” rifle in my suburban/rural “field and forest” habitat vs something I’d use in the house, although some close range practice with it is still wise.

    So far I’ve got about 200 rounds through the gun. No function issues yet and it’s a pleasant shooter. I don’t believe it’s really any more accurate than my shorter guns (since barrel length doesn’t really enhance *accuracy* per se)
    but like my other 20” ARs, it definitely *feels* easier to get good hits with both the ACOG and the Mbus Pro rear sight, presumably due to the long sight radius and lesser recoil impulse.

    Last edited by Circle_10; 10-30-21 at 12:25.

  2. #2
    Join Date
    Jun 2015
    Location
    Indiana
    Posts
    279
    Feedback Score
    0
    WOW! If there was a "like" button I could find, I would most certainly hit it here. I'm drooling over the optic, as much as your rifle. Great looking rig, all the way around!
    Good night Chesty...wherever you are.

  3. #3
    Join Date
    Oct 2008
    Location
    Maine
    Posts
    2,113
    Feedback Score
    3 (100%)
    Thanks! I know in this era of LPVOs some would argue that ACOGs, and other fixed power prisms in general, are obsolescent but personally, having experience with both, I still like them better than an LPVO when it comes to stuff like running around in the woods and getting in and out of vehicles. Perhaps in time I will change my opinion though.

  4. #4
    Join Date
    Mar 2011
    Location
    Mid-West, USA
    Posts
    2,540
    Feedback Score
    60 (100%)
    I like it! I've been thinking about this type of build for a while.

  5. #5
    Join Date
    Aug 2006
    Location
    South Carolina
    Posts
    553
    Feedback Score
    11 (100%)
    I like this. I wish I had just said F'it go with the ACOG but I l am a steiner nerd so I went with the T332 because of price (I was able to get it for under $460 with all the deals I got on it) It works. I also have a S332 I am trying to figure out what to do with it.

    I thought about about a 18inch FSP pencil barrel for awhile but could not find one.

    I have two ACOGs. A TA02 in my 14.5 DD M4 clone that is like my issued rifle minus the the Centurion FSP handguards and my SHTF rifle (I know why). It is my go to and a TA01NSN on a FN just like my M4A1 upper.

  6. #6
    Join Date
    Oct 2008
    Location
    Maine
    Posts
    2,113
    Feedback Score
    3 (100%)
    Quote Originally Posted by ffhounddog View Post
    I like this. I wish I had just said F'it go with the ACOG but I l am a steiner nerd so I went with the T332 because of price (I was able to get it for under $460 with all the deals I got on it) It works. I also have a S332 I am trying to figure out what to do with it.
    How do you like the T332 overall? Given my fondness for prisms, I might still try one out on a different gun in the future.

  7. #7
    Join Date
    Nov 2012
    Posts
    1,143
    Feedback Score
    36 (100%)
    Awesome build, I love 20 guns!

  8. #8
    Join Date
    Aug 2006
    Location
    South Carolina
    Posts
    553
    Feedback Score
    11 (100%)
    Quote Originally Posted by Circle_10 View Post
    How do you like the T332 overall? Given my fondness for prisms, I might still try one out on a different gun in the future.
    My better half loves it. She likes that the whole reticle is bright. She took my unused LWRCi Ic-A2 to the range and was using that compared to her much loved AR-15A2 (actually my first AR) but other than some bump in the night stuff (pregnant) she has only put 150ish rounds in my AR and she likes it and she is a Marine that always said Irons or die. She likes the diopter on the scope too too but she wears contacts. The eye relief is up there with the TA-33.

    I wish i had Bought another S332 when Steiner was blowing them out they are a great option for a prism but acog pricing. I got for just $100 more on a close out and a TA-02 led to try out when I get back from deployment.

  9. #9
    Join Date
    Feb 2010
    Location
    VA
    Posts
    1,845
    Feedback Score
    0
    Great project! I have a very similar build that is one of my favorites to shoot. Almost everything about it is the same, right down to the TA110 LED ACOG. I use the UBR 2.0 at the rear to help counterbalance the 20" a bit.

    "Man is still the first weapon of war" - Field Marshal Montgomery

    The Everyday Marksman

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •