Lightweight AR-15 Carbine

[MarkCO]

Thought you might like to see a picture of my most recent addition. Weighing in at 5.6 pounds complete, the lightweight carbine is based on the Cavalry Arms Polymer lower. Alan Samuel put the lower together along with a slight trigger job. The upper is an A3 with a slightly modified 16" A1 barrel sporting a chrome 5.56 chamber and target crown. It has a sight base gas block and a free float hand guard. The sight is an OKO reflex with integral back-up fixed sights. I plan on a little more maching on the handguard and the gas block to get it down to 5 pounds even (I hope). As you can imagine, a few 30 round magazines through this at a high rate of fire gets the barrel pretty hot. However, POI did not drift noticeably. Recoil and accuracy were actually better than I expected. I'll probably add a light and an off axis fiber optic for close-in, odd angles. After losing 1/2 pound more, that should put me back to about 5.3 pounds.

[vote Republican]

Is that a one piece lower? I'd think on a gun that light, you would go for a collapsible stock.

Humping your rifle up & down some mountains? ;e

[DAIadvisor]

Looks nice. All you need now is a flash hider and a front tac grip . I got a Carbon 15 M4, which I love - 6 pounds compared to my 26 pound full-size A3 HBAR. How is the reliability on the lower? Any problems? Just curious.

[striderglock]

Why the obsession with light-weight on a target rifle?

By the way, sweet looking rifle. Where'd you get the lower and how much?

[MarkCO]

The lower is a one piece A1 length Cavalry Arms Polymer lower (MkII), retail is $260, but they go for as low as $200 depending on source. Collapsible stock would have added about 1 pound minimum. No problems on the lower, and they are lifetime warrantied. No need for a front grip, just wasted weight. I have not ruled out a detachable flash-hider, but right now, not sure I need one for what I want to do. Shooting prone, low cover in the dirt with a flash hider is not fun, not sure I want to sacrifce that. But I left a slightly larger diamter muzzle so I can thread the end of the barrel for a flash hider later if I want. I'm going to a low-light rnage next week to check it out.

I don't consider this a target rifle at all. It is a defense/tactical/urban (whatever word you want) carbine. I'll use it in Tactical class in action competition and for HD. Lightweight (and short) equates to more speed and more manuverability. My 60 degree angled 50 yard target splits dropped by about 40% on this carbine compared to a 7.5 pound carbine. Knowledgeable hi-speed, low-drag operators are always looking for ways to lighten the weight. One reason M4s are popular. Just no one makes a "catalogged" carbine this light except the Carbon 15s, and they have some reliability issues. Very few people do much except plink with their AR-15s, or they hang so much crap off of them that they look like a tactical gear display. When you have run through several tactical competitions, CQB shoot houses in courses and held cover on a position for hours on end with the gun up, you'll start to appreciate lightweight. I have an acquaintance who is on a SWAT team and they are building up 4 rifles just like this except they are going with 14" barrels and surefire light/laser combos, they should come in right at 5 pounds.

[striderglock]

Originally posted by MarkCO
Shooting prone, low cover in the dirt with a flash hider is not fun, not sure I want to sacrifce that. A2 flash hiders are 3-port with closed off bottom so shooting prone isn't a problem. Phantom has a close bottom hider out as well. Aside from not kicking up dirt they compensate some too. For your purposes I would defenitely get one.

Very few people do much except plink with their AR-15s, or they hang so much crap off of them that they look like a tactical gear display. When you have run through several tactical competitions, CQB shoot houses in courses and held cover on a position for hours on end with the gun up, you'll start to appreciate lightweight. ^6

[MarkCO]

Originally posted by striderglock
A2 flash hiders are 3-port with closed off bottom so shooting prone isn't a problem. Phantom has a close bottom hider out as well. Aside from not kicking up dirt they compensate some too. For your purposes I would defenitely get one.

Yes, I understand that, but when I shoot prone under low cover (like les than 6 inches), and it happens in matches as well, I lay the rifle over on the side, and the A2s kick up a LOT of dirt. The old A1 bell type is about the only one that does not let any gas go to the sides, it cuts down on noise to the shooter and hides flash acceptably. If I get one, that will be what I get.

[striderglock]

Originally posted by MarkCO
Yes, I understand that, but when I shoot prone under low cover (like les than 6 inches), and it happens in matches as well, I lay the rifle over on the side, and the A2s kick up a LOT of dirt. The old A1 bell type is about the only one that does not let any gas go to the sides, it cuts down on noise to the shooter and hides flash acceptably. If I get one, that will be what I get. Ah, gotcha.

How do you like your red dot? Most go with an Eotech or Aimpoint. I just got my Eotech today. Why did you choose that one? What did it set you back? What powers it?

[MarkCO]

Originally posted by striderglock
How do you like your red dot? Most go with an Eotech or Aimpoint. I just got my Eotech today. Why did you choose that one? What did it set you back? What powers it?

My reasons were:

1. Recomended by the dealer who put my lower together. He is a small dealer who specializes in ARs and full auto weapons. He said they were rugged and reliable. He puts them on a lot of his auto rentals, that get beat, and they stand up well.

2. They have integral back up fixed sights.

3. VERY lightweight.

4. Built in mount.

5. Long battery life.

6. It uses the large 3v flat disk watch batteries.

Cost was a bit over $150. I've seen them priced from $150 to $230. I like it a lot. I got to compare it to several other dots and sights. The Trijicon Reflex and ACOG are of course better, but forless than 1/2the Reflex and less than 1/4 of the ACOG, I am pretty darn happy with it.

http://www.okousa.com/products.html

[striderglock]

Mark, I missed that one when I was shopping. Wound up with an eotech. I really don't need an Eotech, but I'm glad I got it. The protective hood is rugged and replacable if you bang it up. Awesome sight.

[MarkCO]

Link error fixed, thanks niner

[Grog]

For anyone else thinking about a cav arms lower, you can get the stripped lowers for about $100. I'm getting ready to order two (one stripped, one built) and got with a J&T LW 16" upper.

I'm already building a DPMS lower, but that'll be finished soon.

Cav Arms is ;j

P.S. The magwell is also wide enough to take .45 greasegun mags ;f