Rock River Lightweight Mountain Rifle

[btmj]

I have two questions, and I welcome all comments…

1) Does anyone have experience with the Rock River Lightweight Mountain Rifle? I have a 2011-vintage Rock River M4-copy with an HBAR 16” barrel, a meaty solid aluminum free float hand guard, and scope. I am happy with the accuracy, but It is a heavy beast at 9.75 lb. I would like to buy a new upper with the intent of getting a much lighter firearm. RRA lists the Lightweight Mountain Rifle at 6.2 lb, so I am guessing that putting “Lightweight Mountain Rifle Upper” on my receiver would result in something similar. I will use a red-dot sight (probably EOTECH) and flip-up irons.

2) Although I am very happy with RRA, I am not committed to this roll-mark… any other suggestions for a light-weight accurate upper with 16” barrel? The RRA upper is $700, so I am looking for suggestions in that general range.

Thanks.....

 

[COSteve]

RRA's 16" lightweight 'Mountain Rifle' AR at 6.2lbs sounds great until you notice that it doesn't have any sights or a sling so it's incomplete as sold. Further, it's got a rail which just begs one to add more 'stuff' to weigh it down.

I started with a RRA Elite CAR A4 mid-length gas, HBAR carbine I bought 14 years ago and after loading it up with junk for the first year, I realized that I wanted light weight. 12 years ago, RRA didn't offer a lightweight barrel option like they do now so, I sent the upper to Steve at ADCO to have the barrel re-profiled as a lightweight and shortened to 14.7" with a silver soldered A2 FH. That took off almost a full 1½ lbs of weight alone.

Even though it's shorter, it's now more accurate as Steve gave it a great crown on the muzzle. It's a great bowling pin shooter at 200 yds even with iron sights so it's plenty accurate with the included 2 stage NM trigger and my 55 and 62grn Hornady fmj handloads.

I completed the lightweight makeover by adding a CTR buttstock, Enidine buffer, MOE mid length handguard, a Troy BUIS rear sight, a customized pistol grip to fit my hand much better, a mountain trigger guard, and a simple cotton sling.

Simple, lightweight, accurate, and reliable. As it sits as a complete usable carbine, empty it weighs 5lbs 15oz and loaded with a full 30rd mag, it weighs 7lbs 0oz. Now that's a real 'Lightweight Mountain Rifle'. The proof of the end product is that I've had it this way for 12 years and have no desire to mod anything on it.

 

[COSteve]

BTW, for a bit longer range shooting in a rock stable AR (how about shooting medium size apples at 400yds) I took my RRA A4, added a real walnut stock set, a custom walnut target pistol grip, a decent compact 12x scope, and simple sling. Not a lightweight by any means at 10lb 11oz empty and 11lbs 12oz with a full 30rd mag, but solid and accurate as heck. It makes vaporizing those pesky apples a pleasure.

Together, they make quite a pair of ARs.