Discussion in 'Rifle Country' started by Justin, Mar 4, 2016.
for instance will a lightweight barrel save me more weight than a skeletonized float tube?
Go with polymer back up sights.
Colt bolt carrier that has been milled all the way out on the bottom.
Polymer frame and polymer buffer tube for weight savings.
No frills (ambidextrous safety, ambidextrous magazine release, ambidextrous bolt stop release, ambidextrous charging handle, no flash suppressor, no stabby thing mount on the front sight base).
Single point sling mount.
And yes, the polymer handguards are lighter than metal...both on the gun and on the pricetag.
Put on a low profile gas block and smooth aluminum free float tube (no rails) and flip up sights. I got a tube from Midwest Industries that weighs about nine ounces.
Single point sling, as mentioned by Gary.
Personally, I'd stick with aluminum for the buffer tube and lower. Saving weight forward of the receiver makes a much bigger difference in handling than weight at or behind the receiver. Same with bolt carriers. Lighten things up too much and you might (not will, might) have issues with overgassing due to not enough weight in the carrier.
However, if this is strictly about a number on a scale, ignore my previous paragraph.
There are sources for titanium parts and folks have built AR's well under 4 pounds.
The majority of the weight savings is to delete the FSB and relieve barrel weight to the minimum. After that the bolt carrier, then skeletonized the lower and upper.
The MFT Minimalist is one of the lightest stocks under 6 oz.
It's a fun hobby but under the 5 pound mark costs start going up geometrically. I have a 10.5" AR pistol at 5.5 pounds, the 6.8 16" deer rifle is 6.5 pounds with a recon weight barrel. Nothing at all to brag about - but back in the day of heavily tricked out quad rail M4geries weighing 8-10 pounds they are light. After a full day's still hunting thru dense brush you notice an extra pound easily.
It's the same game mountain rifle builder's get into, how much weight can be lost affordably and still carry enough gun?
Pretty easy to build a ~5 lb carbine today with the right barrel, handguard and stock. A Faxon 14.5" pencil barrel with permanent Ti muzzle device, a 10" BCM KMR handguard and one of the lighter carbine stocks like the MFT Minimalist will get you there using standard upper & lower receivers.
Once you factor in the barrel nut/delta ring assembly, end cap and FSB, a lot of aluminum FF handguards with low profile gas blocks are lighter than stock plastic furniture.
-Tiny, vestigial sights instead of a rail (think WWII pistols)
-SBR, preferably <3" with an approximately 1" gas system (it's been done successfully)
-Polymer upper/lower receiver
-Ultra-short buffer tube (I've seen ~5" models out there)
-Tennis ball in lieu of a real stock
-No front handguard, just use the magwell or mittens
-Pistol grip cut down to two-finger derringer specs
-Titanium trigger guard
Lots of upper assemblies to choose from. Most of them had aluminum handguards. Probably free floated with interesting designs cut in them to reduce weigh but I suppose mainly for looks.
The only M-4 type upper I saw was in 300 Blackout. By the way .300 uppers were common.
Everything comes at a cost.
The less weight you have forward of the handgrip ( including closer to the hand grip ) the more nimble it will feel.
So the barrel and FF tube , as well as the gas block can dramatically alter a AR's "feel".
You don't need exotic parts just lighter than normal.
My 14.5 BCM ELW Fluted is VERY nimble.
Love it! A derigibAR, the HindenburgAR (trademark of LaRue Tactical...probably)
guess it's been 2 years since my last build... http://www.thehighroad.org/showthread.php?t=761427 that one is 5 lb 6 oz and didn't break the bank. i have some of the weight savings for magnesium aluminum components in the OP
The two weight savers that stood out for my build was the aluminum bolt carrier and the monolithic cav15 poly lower.
These save right at a lb by themselves not because of the lower so much as the stock, buffer tube, and castle nut all being poly and integral
For the lower, I used a factory ATI Omni gen I complete lower. It weighs in just a hair under 6 pounds unloaded. I could possibly shave off a few ounces by going with a slick side upper, milled out BCG and half a dozen other things people do to shave weight. But I like the current weight and balance of the rifle, and with a 20 round aluminum GI mag, it's still under 6.5#. Nice little light weight rig.
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