Project Überlight: sub 4lb SBR; sub 5lb suppressed.





Following on the heels of my successful project Noveske Ultralight I was bitten by the lightweight bug. Link deleted by moderator.

That sub 6lb ultralight home defense rifle was built balancing parameters favoring reliability and key features of a HD rifle as is documented in the thread. It also took awhile as it was on the front end of the ultralight craze (and in fact it continues to be updated), but already by its finish, I had in mind what it would take to make a radically lightweight rifle by prioritizing lightweight above all else. Certainly the idea was obsessive and possibly insane but it would be enjoyable. The goal for Project Überlightlight was to build the lightest rifle possible using the strategy of compounding weight savings through combined ultralight parts selection. Sub 4lbs/64oz was the ultimate target weight even though I knew it was a long shot.





Build parameters had to be set out of the gate for parts selection.


1) I wasn't going to use custom, one-off or non-commercially available parts. Largely V7 Weapon Systems, 2A Armament, and BCM made this possible.


2) The priority of lightweight meant the rifle would be relegated to the realm of a range toy, which allowed for experimenting with ultralight parts to that end (ultralightweight carrier, buffer, etc.).


3) No cheating! When weighed, the rifle had to have at least one sight system and include the attachments with which it would be used (QD sockets, etc.).





Even with these parameters set, the build floundered. I had been working on it for over a year and have at times waited for months on parts to be released only to change direction. The problem I ran into was the thing is a huge money pit and it actually needed more direction than simply the lightest range toy possible. Originally Überlight was going to be a 14.5" Mid BCM ELW-F 556 barrel with pinned V7WS extended A2 v-grooved flash hider, 10" KMR rail, and slick side upper--but that was too close to what I already did with Noveske Ultralight and not enough lighter to be worth it. At that point, going short barreled rifle was the clear path to take; an 11.5" BCM ELW-F barrel was the plan. Shorter, lighter, and different. Yet still, SBR wasn't enough. If I was going to dump money into a range toy the rifle needed to be an exceptional range toy, not just an insanely lightweight rifle that still went bang. I wanted Überlight to wow it was so light and also be fun to shoot, otherwise it was not worth it. That is when .300blk emerged as the clear choice.





300blk is designed for complete powder burn down to 8" of barrel length allowing for further weight savings using sub 10" barrels without creating an abomination. Also, for a given barrel profile, a 30cal barrel is actually lighter than a 556 barrel due to less wall thickness. The problem is most short barrels have heavy profiles and end up only being a little lighter than longer, lightweight profile barrels. This did not fit the strategy of compounding weight savings and would simply not do. That's when V7WS released their 8.25" .300blk barrel with a modest profile and a fluting option: 15.15oz stripped. Perfect! But what 7" rail to use? BCM's magnesium alloy KMR is the defacto go-to ultralight rail system especially when combined with V7WS titanium KMR barrel nut and hardware. Thankfully I didn't have to wait long as BCM made a surprise announcement that the 7" KMR was available around the same time I purchased the barrel. Überlight finally came together with a clear direction and, surprisingly, right at the sub-4lb target weight.






































Parts List, Phase 1: 63.5oz





Upper:


-2A Armament Balios-lite 7075 billet slick side upper receiver


-V7WS 8.25" .300blk stainless steel barrel


-V7WS .750" titanium set-screw gas-block


-Spike's Tactical Melonite pistol gas-tube


-V7WS titanium 762 Furion Muzzle Brake


-BCM KMR magnesium alloy 7" rail


-V7WS titanium KMR barrel-nut (soon to add titanium KMR clamp blocks)


-V7WS lightened mil-spec charging handle


-V7WS aluminum ultralight port-door


-V7WS aluminum port-door rod


-V7WS headspace matched melonite 9310 bolt


-Boomfab Titane titanium bolt carrier


-RCA melonite gas-adjustable carrier key


-RCA melonite firing-pin


-V7WS 4340 melonite cam-pin





Lower:


-2A Armament Balios-lite 7075 billet lower receiver


-V7WS first run 7075 carbine receiver extension


-Battle Arms Development BAD-LBS-MIL 7075 billet butt-stock


-V7WS aluminum end-plate


-V7WS aluminum alloy castle nut


-Taccom ultra-lightweight deralin AR15 carbine buffer


-SpringCo white carbine spring


-V7WS titanium buffer retainer


-V7WS aluminum alloy pin set


-V7WS S7 lightened bolt catch


-V7WS aluminum alloy mag catch


-V7WS aluminum mag release button


-V7WS titanium core, aluminum lever rightside 57* safety selector


-Magpul original K grip


-V7WS titanium grip screw


-Geissele SD3G trigger


-V7WS titanium Geissele trigger pins





Attachments:


-Trijicon RMR RM06 adjustable 3.25moa dot RDS sight


-LaRure Tactical LT827 RMR lower 1/3rd QD mount


-Spikes Tactical aluminum Billet Micro Folding Sights w/ titanium bolts


-V7WS aluminum BCM keymod QD socket


-Noveske NSR single keymod handstop (adds .2oz, not pictured)





The rifle shoots great! This configuration is amazingly handy and surprisingly balanced in it's shortness. The V7WS Furion brake is quite effective at mitigating recoil and helps with some of the snap of the superlight reciprocating assembly. Adjustable gas was a necessity with this set-up as the total weight of the Boomfab Titane carrier and Taccom ultralight carbine buffer is only about 5.1oz. FTF malfunctions due to excessive BCG speed is a concern as well as increased gas blowback from high chamber pressures with quick bolt unlock. In order to save weight using the V7WS titanium gas-block the RCA adjustable gas-key was the best solution. The key is the same weight as a mil-spec gas-key and fit on the ultralight Boomfab Titane carrier, 4.4oz w/ key. After messing with the adjustable gas-key I had subs reloading without locking back on empty and supers shooting with full function. The subs with the brake and gas adjustment were ridiculously soft shooting, but who builds a .300blk SBR range toy without provision for suppressed subsonic loads? Enter Phase 2.



































Parts List, Phase 2: 76.9oz


-SilencerCo Omega 762 direct thread silencer


-DSArms CAR type Fiberite stock (Colt CAR N1 clone)





The SilencerCo Omega is an excellent match for his build. SiCo struck a great balance between durability with the stellite blast baffle and lightweight with the titanium tube and stainless steel baffles, resulting in a full-auto rated can weighing only 13.35oz mounted*. Testing with 100 rounds of Remington UMC 220gr .300blk through the can was 100% without changing the gas settings on the key mentioned above. Due to the faster carrier speed of the lightweight set up and faster unlock time, I was getting quite a bit of gas in my face suppressed, especially shooting supers (Fiocchi 150gr .300blk). I think for the next outing I will adjust the gas-key to shoot supers unsuppressed with full function but to not cycle with subs unsuppressed (who shoots subs without a can anyway?). This should give me the best gas mitigation I can get with the set up. Though I am not sure if regulation at the carrier key will cut down on blowback much anyway. I imagine more gas escapes from the upper receiver than would if regulation at the gas-block kept gas from entering the gas-tube in the first place, since the gas is already in the gas-tube pressurized when the gas-key uncovers the gas-tube as the carrier moves rearward. Many companies are working on products that regulate at the gas-key (SunDevil Mfg, RCA, 2A Armament, Gemtech), I am curious what their testing has shown.
-Omega stripped w/o mount or end-cap insert: 9.75oz


-Omega/Harvester Big Bore 5/8X24 direct thread mount: 2.2oz


-Omega/Harvester Big Bore ASR mount (adds .825" OAL over direct thread mount): 3.45oz


-ASR Muzzle Brake 5/8x24 762mm: 3.65oz


-ASR Muzzle Brake 1/2x28 5.56mm: 4.0oz


-Omega 762mm flat end-cap (ferrous): 1.4oz


-Omega Anchor Brake end-cap (nonferrous, adds .9" OAL over flat end-cap): 1.5oz


Totals:


-Omega with ASR mount and Anchor Brake end-cap: 14.7oz & about 8 inches OAL ( minus .1oz and .9 inches for flat end-cap)


-Omega with 5/8x24 direct thread mount and 762 flat end-cap: 13.35oz & about 6.25 inches OAL ( add .1oz & .9 inches for Anchor Brake end-cap)*





[suppressed subs video] coming soon





Parts comments:





-BAD-LBS-MIL w/ V7WS parts (7.2oz) vs. ACE AR-UL-E (9.15/6.55oz)


The 3.2oz BAD-LBS-MIL is not necessarily revolutionary but it does offer some advantages over the similar ACE AR-UL-E set-up. First, the BAD-LBS-Mil has the integral QD socket. Second, despite the AR-UL-E being lighter when minimally configured (6.55oz) the BAD-LBS-MIL attaches to a standard buffer tube, which allows for swapping out an adjustable stock with just a simple bolt. Because lets be frank, the LOP sucks with just a carbine buffer tube and there are times you want the adjustment of a real stock. With the V7WS .4oz end-plate/castle nut combo, and 3.6 oz carbine buffer tube, the total weight is still only 7.2oz with the BAD-LBS-MIL 3.2oz stock. The flexibility of swapping an adjustable stock is also the main reason I did not consider the 6.9oz (spec) Sabertube, QD end-plate, BAD-LBS combo, despite it having a longer fixed LOP http://www.battlearmsdevelopment.com/sabertube-tm-qd-end-plate-bad-lbs-lightweight-stock-combo





--AR-UL-E fixed carbine stock assembly: 9.15oz, *6.55oz minimally configured


 receiver extension tube: 2.65oz*


 foam pad: .55oz


 gusset/clamp w/ screw: 1oz*


 sling mount (w/o additional plug screw): .35oz


 clamp-on butt w/ screw: 2.9oz*


 rubber butt pad w/ screws: 1.7oz
--RCA adjustable gas-key vs. SunDevil MFG adjustable gas key (same weight)


One complaint about the RCA gas-key is there is not enough threads in the key for the lock screw to solidly engage if the adjustment screw is backed off most of the way, i.e. little regulation means the lock screw only has about 1 twist into the key before bottoming out on the adjustment screw, which is not enough to tighten it well and not enough for loctite or rockset. Though it is not an issue if the adjustment screw is threaded in for more regulation as there is more room for the lock screw to thread in behind it. Originally I thought the RCA lock screw design was a big improvement over the SunDevil Mfg key with only one screw and a nylon friction detent since the one screw can not be adjusted as desired, then removed, loctited and reinserted to the exact same position (I think SunDevil intends the nylon friction detent to be sufficient securement), but depending on how much regulation you want, the RCA key may not work for you. Believe me, you do not want that lock screw to come loose in the upper! I got lucky that it only wedged underneath the trigger and put me out of service for 15min while I frantically figured out why the trigger in my SBR lower went dead!





Link deleted by moderator.




--Boomfab Titane titanium bolt carrier (4.4oz w/ key) vs. JP LMOS aluminum bolt carrier (3.76oz w/ key)


So the JP LMOS aluminum bolt carrier is lighter than the Boomfab Titane titanium carrier. Call me crazy to spend that much on a bolt carrier but come and lock me up if I spend the same on a carrier said to be a consumable wear item as particulate and hot gasses blast the aluminum while steel gas-rings grind on it. JP specifies the aluminum LMOS is intended for games guns with mid-length to rifle gas-systems http://jprifles.com/buy.php?item=JPBC-1 .300blk with pistol gas was too much of a gamble with the money, though I would happily test one out if JP wanted to sponsor it! ;)





--Trijicon RMR RM06 primary RDS vs. Aimpoint Micro primary RDS





Previously I compared these two lightweight RDS solutions with regard to a defensive rifle. The clear winner for that use is the 3.05oz Aimpoint Micro mounted on a 1.3oz ScalarWorks LDM QD micro mount (or a fixed 1.3oz Fortis F1 mount before the LDM). The older 3.65oz RM34 and 3.5oz ADM RMR QD mounts were so heavy that the Aimpoint Micro mounted was actually lighter than the 1.25oz RMR mounted, making the choice even more obvious. But the new Larue Tactical LT827 QD RMR mount has changed that as it weighs only 2.35oz. Mounted, the 1.25oz RMR on a 2.35oz LT827 is lighter at 3.6oz than a 3.05oz Aimpoint T1 mounted on a 1.3oz ScalarWorks LDM for 4.35oz total. While the Larue mount is exceptional in quality and is unique with a lower 1/3rd co-witness that opens up the view of the tiny RMR window, there are still too many feature draw backs with the RMR to consider it over an Aimpoint Micro for defensive use, IMO. The optical distortion, among other features, of the RMR is poor in comparison to the Micro. Project Uberlight, however, does not have the same defense requirements, so since the RMR mount on a LT827 is lighter, it went on the gun. However, looking at the 1.3oz weight and the quality of the ScalarWorks LDM QD and Fortis F1 fixed Micro mounts, there is no reason a RMR mount couldn't be made weighing 1oz or less with the same quality. I am still waiting on this to happen and will switch when it does. The RMR is still a good sporting primary RDS or secondary defense RDS especially among other open micro reflex sights.












2A Armament Balios-lite billet lightweight receivers vs Battle Arms Development billet lightweight receivers





2A Armament takes the cake for lightweight receivers. Their machining is perfection and the lightweight cuts do not look overly busy aesthetically. BAD also makes a lightweight receiver set but it is not quite as light as the 2A Armament set and does not look as nice, IMO. BAD also has a version of their receivers available only on the special edition OIP rifle but that set is not available for purchase and weighs the same as the 2A Armament Balios-lite set (with the tension screw removed), yet it does not have a full top rail and has lightning cuts that I personally find visually displeasing and unnecessary in comparison.





What about Mag Tactical's cast magnesium receivers? I value my eyesight too much to risk using a cast magnesium upper and there is no way I would SBR one of their lowers. Tennessee Arms Co makes a nylon lower receiver with brass reinforcements that is exceptionally light but at this time I am still evaluating if their lowers are something I would consider SBRing. Even so, I probably wouldn't replace the Balios-lite lower on this project as it is excellent and matches the upper.





Spike's Tactical Micro Sight Set (1.9oz) vs Bobro lowrider sight set (1.7oz)





Spike's Micro sights thread:


Link deleted by moderator.

I was not very impressed with the Spike's sights in comparison to others but for a ultralight .300blk build they are great and the somewhat goofed adjustable elevation is still nice given the low velocity of the round. For comparison the Bobro lowrider sights each weigh .85oz for a total of 1.7oz, but I already had the Spike's sights laying around, so they went on the build. I may take the sights off the gun and just run the RMR but weight was made with the sights so there is not much of a reason to remove them.
----





Big thanks to V7 Weapon Systems, Bravo Company USA, Boomfab and 2A Armament, among others listed above for their innovative parts making this build possible. I would like to point out nothing about this build was sponsored. I am not affiliated with any of the companies from which I sourced parts. My opinions are my own. Thanks for viewing!
 

For anyone interested in weight savings on future builds.


Parts weights for reference (measured [+ or - .025oz], if not weighed source link is shown)





[SIZE=3]Lower Half[/SIZE]





Lower Receivers:


-Standard Noveske N4 lower: 8.85oz stripped (MOE trigger guard assembly: .22oz


together = 9.07oz )


-Gen 2 Noveske stripped lower w/ integral trigger guard and flared mag well: 9.75oz stripped


-Rainier Arms RM15 lower and A-DAC forged lower (w/ .05oz tension screw; made by MEGA): 8oz stripped (not sure why it is .85oz lighter than the Noveske?)


-Aero Precision stripped forged lower: 8.35oz


-2A Armament BALIOS-lite stripped lower w/ integral trigger guard: 6.55 oz stripped


-Battle  Arms Development BAD556-LW Lightweight 7075-T6 bilet lower: 6.8oz


http://www.battlearmsdevelopment.com/bad556-lw-lightweight-7075-t6-billet-lower-receiver


-Mag Tactical Systems magnesium lower w/ integral trigger guard: 5.875oz stripped


http://www.magtacticalsystems.com/index.php/2013-07-29-03-32-34/2013-08-01-17-32-25/product/10-black-lower#specs





Lower Parts





Trigger guards:


-KAC trigger guard (new version): .4oz


-MOE trigger guard assembly: .22oz





Triggers:


-ALG QMS mil-spec trigger: 2.55oz


-LMT 2-stage trigger: 2.25oz


-Geissele SSA, SD-C and SSA-E, SD-E: 2.25oz


-Geissele SD3G: 2.25oz (w/4.5# spring 2.3oz)


-CMC flat trigger 3.5# w/ stock pins: 2.75oz


-V7WS Titanium Geissele trigger pins:  .083oz (3 sets weighed .25oz) and the stock steel Geissele pins weigh close .14oz (3 sets weighed in at .40/.45oz). The V7 -TI trigger pins were exactly the same diameter as all of the stock G pins (.1545" with my calipers) and were consistently .003" longer than the stock pins.





Safety Selectors:


-Noveske STS ambi safety selector: .55oz


-DD mil-spec safety selector: .6oz


-BAD CASS SA/ST (long & short) safety selector: .85oz


-V7WS right hand 57* selector: .3oz


-V7WS ambi (long,short) 57* selector: .35oz





Bolt Catchs:


-Colt bolt catch: .4oz


-V7WS S7&8620 Bolt catch: .3oz


-Seekings enhanced bolt catch: .55oz





Takedown/pivot pins:


-Noveske nitrocarburized pin set: .5oz


-DD mil-spec pin set: .5oz


-BAD Enhanced Pin Set: .5oz


-BAD Titanium EPS Ionbond black: .3oz


-V7WS Titanium pin set: .3oz


-V7WS aluminum-alloy pin set: .17oz





End plates & castle nuts:


-V7WS alum. QD endplate: .18oz (3 weighed and divided)


-IWC steel QD endplate: .65oz


-Noveske QD steel endplate: .5oz


-Vltor steel endplate: .5oz


-DD alum. QD endplate: .225oz


-V7WS alloy castle nut: .225oz (3 weighed and divided)


-Vltor steel castle nut: .65oz


-DD steel castle nut: .6oz





Mag catch assembly:


-V7WS alum. alloy mag catch and alum. mag button: .17oz (2 weighed and divided)


-Colt mag catch and mag button: .35oz





Pistol Grips & Grip bolt:


-Original MOE-K grip: 2oz (current version is thicker 2.2oz)


-UCWRG Grip 23: 2.35oz (no grip plug by design)


-MOE grip: 2.55oz (w/ .2oz grip plug)


-MOE-K2 grip: 2.65oz (w/ .2oz grip plug)


-A2 grip: 2.8oz


-MOE Plus grip: 3.25oz (w/ .2oz grip plug)


-Magpul steel grip bolt: .25oz


-V7WS titanium grip bolt: .1oz





Reciever Extentsions, Springs, and Buffers:


-Vltor A5SR 6 pos. RE: 4.05oz


-Vltor A5 7 pos. RE: 4.25oz


-DD 7075 carbine length RE: 3.8oz


-V7WS 7075 carbine RE (original first run): 3.6oz


-V7WS 7075 carbine RE (later run but before reliefs between notches): 3.7oz


-V7WS 7075 carbine RE (current w/ reliefs between notches): 3.8oz


-Phase 5 tactical pistol RE: 5.2oz (w/ foam pad), 4.8oz (w/o foam)


-Vltor rifle spring: 2.2oz


-Springco green spring: 2oz


-DD carbine spring: 1.85oz


-Springco blue CS spring: 1.6oz


-Springco white CS spring: 1.5oz


-Primary Weapon systems H4 carbine buffer: 6.95oz





Stocks:


-Battle Arms Development, BAD-LBS-MIL stock : 3.2oz (w/ .2oz steel bolt)


-AR-UL-E fixed carbine stock assembly: 9.15oz, *6.55oz minimally configured


 receiver extension tube: 2.65oz*


 foam pad: .55oz


 gusset/clamp w/ screw: 1oz*


 sling mount (w/o additional plug screw): .35oz


 clamp-on butt w/ screw: 2.9oz*


 rubber butt pad w/ screws: 1.7oz


-Colt N1 CAR stock: 4.4oz


-DSArms fiberite CAR type stock: 4.6oz


-Colt/Rogers Super-Stoc: 6.56oz


-MOE stock: 8.55oz


-MOE-SL stock: 9.7oz


-LMT SOPMOD w/ storage plugs: 11.55oz


-Magpul SRT stock (w/ stock 1.5oz buttpad and screws): 13.05oz


-LMT DMR308/762: 22.6oz





[SIZE=3]Upper Half[/SIZE]





Upper Receivers:


-Standard mil-spec forged upper: 8.6oz with .7oz mil-spec port door assembly &     .75oz forward assist assembly, 7.15oz stripped


-Vltor MUR 1s minus forward assist : 8.4oz w/ mil-spec port door assembly, 7.65oz stripped http://www.m4carbine.net/showthread.php?87685-Weight-amp-advertising-Vltor-MUR-1s


-Rainier Arm's mil-spec profile forged upper minus f/a: 7.3oz w/ mil-spec port door assembly, 6.6oz stripped


-2A Armament BALIOS-lite upper minus forward assist: 5.75 oz stripped


- Battle Arms Development BAD556-LW Lightweight 7075-T6 Billet upper: 6.31oz


http://www.battlearmsdevelopment.com/bad556-lw-lightweight-7075-t6-billet-upper-receiver


-V7WS forged M4 upper: 6.9oz stripped http://www.v7weaponsystems.com/collections/frontpage/products/v7-m4-stripped-upper


-V7WS basic mil-spec forged profile upper minus f/a & minus port door mounts: 6.4oz stripped http://www.v7weaponsystems.com/colle...upper-receiver


-Vltor MUR 1a (Noveske/old style): 9.6oz w/ mil-spec port door & f/a, 8.15oz stripped http://www.militarymorons.com/weapons/ar.uppers.html


-Mag Tactical Systems magnesium upper: 4.8oz stripped http://www.magtacticalsystems.com/index.php/uppers/assembled-uppers/product/219-assembled-upper#specs





Upper Reciever Parts:


-mil-spec steel port door: .525oz


-V7WS AR15 alum. port door: .26oz


-V7WS AR10/SR25 alum. port door: .3oz


-mil-spec steel port door rod: .2oz


-V7WS AR15 alum. port door rod: .07oz


-V7WS alum./steel forward assist (w/o spring): .32oz


-steel mil-Spec forward assist (w/o spring): .72oz


-Boomfab Titane titanium bolt carrier w/ gas-key: 4.4oz


-JP LMOS QPQ steel carrier w/ gas-key: 6.7oz


-JP LMOS Aluminum carrier w/ gas-key: 3.76oz http://jprifles.com/buy.php?item=JPBC-1





Charging Handles:


-BCM Gunfighter CH Mod 4 (med latch): 1.25oz


-BCM Gunfighter CH Mod 5 (small latch): 1.15oz


-AXTS Raptor: 1.4oz


-Mil-spec charging handle: 1.15oz


-V7WS lightened mil-spec charging handle: 1oz





Muzzle Devices:


-V7WS titanium A2 spec flash hider: 1.05oz


-V7WS titanium v-grooved extended A2 flash hider: 1.25oz


-2A Armament Titanium T3 Comp 556: 1.5oz


-BCE 2.0 ( w/o shims): 1.8oz


-V7WS Titanium 762 Furion Brake: 1.5oz (w/  .5oz crush washer)


-V7WS Titanium 556 Furion Brake: 1.85oz (w/ .1oz crush washer)


-Adams Arms/Voodoo Innovations Manimal Low Profile <.750” Extended A2 Flash Hider: 1.5oz


-BCE 1.5 (w/ .1oz crush washer): 2.1oz


-PWS FSC556 (w/o shims): 2.45oz


-BCM Mod 1 gunfighter comp: 2.8oz


-KAC MAMS 556 1/2x28 (with shims): 2.45oz


-Surefire SFMB556 1/2x28 (w/ shims): 3.95oz


-SilencerCo Trifecta Brake 1/2x28 556 (w/o shims): 3.95oz


-SiCo ASR Muzzle Brake 5/8x24 762 (w/o shims): 3.65oz


-SiCo ASR Muzzle Brake 1/2x28 5.56 (w/o shims): 4oz





Gas Blocks:


-Syrac .625 adj. gas block (w/ 2 set screws): 1.4oz


-V7WS .625 titanium gas block (w/ 2 set screws): .75oz


-V7WS .750 titanium gas block (w/ 2 set screws): .8oz





Barrels:


-8.25” V7WS .300blk fluted stainless barrel: 15.15oz stripped


-11.5" carbine BCM ELW-F enhanced lightweight fluted weigh: 16.85/16.95oz (two measured stripped)


-14.5” Mid Faxon Firearms 556 Pencil 4150 QPQ barrel: 17.44oz stripped http://www.faxonfirearms.com/p/113/145-556-ar-15-4150-black-qpq-pencil-mid-gas


-14.5" Mid Noveske Skinny barrel: 20.85oz stripped


-14.5" Mid BCM Standard ELW-F: 20.55oz stripped


-BCM ELW/F Barrels courtesy of MilitaryMorons:


14.5” ELW 1.324 lbs = 21.184oz


14.5” ELW-F 1.292 lbs = 20.672oz ---.512oz difference


16” ELW 1.421 lbs. = 22.736oz


16” ELW-F 1.388 lbs. = 22.208oz ---.528oz difference


-16” Mid Faxon Firearms 556 Pencil 4150 QPQ barrel: 19.05oz stripped http://www.faxonfirearms.com/p/81/16-556-ar-15-4150-black-qpq-pencil-mid-gas





Rails Systems:


-BCM KMR 7" rail only: 3.05oz


-BCM KMR 10" rail only: 4.3oz


-BCM KMR steel barrel nut: 1.6oz


-BCM KMR mounting hardware: .70oz


-V7WS Titanium BCM KMR barrel nut: .9oz





RDS, RDS mounts, and RDS accessories:


-Aimpoint Micro T1 w/o mount: 3.05oz


-Aimpoint Micro bikini lens cover: .3oz


-Tangodown IO Cover: .55oz


-KAC Micro battery cap: .225oz


-Stock Aimpoint Micro battery cover: .2oz


-CR2032 battery: .1oz


-ScalarWorks LDM (quick detach, 1/3rd co-witness): 1.3oz, 4.35oz w/ micro T1 (weighed together)


-Fortis F1 (fixed, 1/3rd co-witness): 1.3oz, 4.35oz w/ Micro (weighed together)


-Larue Tactical LT751 (QD, absolute co-witness): 2.45oz , 5.55oz w/ Micro (weighed together)


-DD Micro mount (fixed, 1/3rd co-witness): 1.7oz


-Trijicon RMR-06 (w/ 2 mounting screws and .1oz battery): 1.25oz


-LaRue Tactical LT-827 RMR mount w/ QD lever (lower 1/3rd co-witness): 2.35oz, 3.6oz w RM-06 mounted (weighed together)


-Trijicon RM34 mount (QD, absolute co-witness): 3.65oz , 4.9oz w/ RM-06 mounted (weighed together)


-ADM RMR Mount co-witness: 3.5oz





Back-up sights:


-Bobro lowrider sights (aluminum) = 1.7oz


  .85oz rear


  .85oz front


-Spikes Tactical micro sights (aluminum) = 1.9oz


  1oz rear w/ adjustable elevation


  .9oz front


-Magpul MBUS G2 (polymer) = 2.5oz


  1.16oz Front


  1.3oz Rear


-MBUS PRO (steel) = 3.3oz


  1.52 oz front


  1.79 oz rear


-DD fixed sights (aluminum) = 2.8oz


  1.1oz front


  1.7oz Rear


-KAC Micro (steel) = 2.85/3.15oz


  1.35oz front


  1.5oz rear 300m


  1.8oz rear 200-600m


-Troy = 3.3oz


  1.56oz front


  1.76oz rear


-RoschWorks SL-1 fixed front sight with integrated 1x CR123a light: 3.3oz


-TangoDown Front Sight Flashlight Adapter FFA-01: 2oz, w/ 3oz Inforce WML = 5oz





Lights, light mounts, and accessories:


-RoschWorks SL-1 fixed front sight with integrated 1x CR123a light: 3.3oz


-Inforce APL: 2.83oz  


-Inforce WML (w1x CR123a): 3oz


-Noveske keymod 1" flashlight ring mount: 1oz


-IWC/HSP 45* offset keymod light mount base w/.5oz 1" ring w/ bolts: 1.4oz


-Surefire G2X tactical (w/ 2 cr123a): 4.85oz


-Surefire scout tape switch: .75oz


-Surefire sr07 tape switch: 1.1oz





Rail and handguard attachments:


-Magpul MOE RVG: 3.3oz


-DD vertical grip: 2.7oz


-Magpul rail ladder: .375oz


-Noveske 4 slot aluminum keymod rail section: .65oz


-BCM 3" nylon keymod rail section: .45oz


-BCM 4" nylon keymod rail section: .6oz


-KAC thumb stop: .3oz


-KAC URX 4 keymod handstop: .32oz


-IWC keymod hand stop: .55oz


-BCM keymod QD vert grip: 2.8oz


-MOE 5 slot rail section: .75oz


-Noveske NSR keymod rail panel pack: 1.4oz


 7 section: .55oz


 single section: .07oz


 single section stop: .2oz


 two section stop: .25oz





-V7WS/BCM aluminum keymod QD socket: .2oz


-BCM steel keymod QD socket: .3oz


-Noveske steel keymod QD socket: .3oz


-IWC steel keymod QD socket: .3oz


-Odinworks K-pod, keymod Harris bipod mount: .8oz





Accessories:


-Harris bipod BRM: 13oz


-BFG VCAS acetal padded: 5.8oz


-IWC 2 to 1 11/4" adapter: .4oz


-IWC QD swivel: .9oz


-MI HD flush QD swivel: 1oz


-Noveske flush mount QD socket: .3oz


-IWC micro mount QD socket: .23oz





-G2 PMAG 20 (w/o .35oz dustcovers): 3.55oz


-G3 PMAG 20: 4.25oz


-G2 PMAG 30: 5oz


-G3 PMAG 30: 5.1oz


-E-MAG: 4.65oz


-PMAG 40: 6.2oz


-D&H 30 Teflon w/ Magpul follower: 4oz





Some links with part weights:





https://spreadsheets.google.com/spreadsheet/lv?key=0Ajl2UPK0UHPsdHNVX2tBak9OS29HR2ZrRFBhUVpYMVE&hl=en





http://blogs.militarytimes.com/gearscout/2012/02/01/buttstock-bashfest-gearscout-finds-out-just-how-far-tough-talk-goes/





Link deleted by moderator.




Link deleted by moderator.




Link deleted by moderator.




http://www.ar15.com/forums/t_3_118/638524_Lightweight_Parts_List_with_WEIGHTS__AR_15_.html&page=1





http://test.ak47.net/mobile/topic.html?b=3&f=118&t=625051&page=1
 

That's crazy man. I'm used to carrying around an 11 lb rifle, under 4 is nuts.

awesome. my .44 magnum unloaded was heavier than that.

Well, I'm impressed.  How does it run?  Sorry if you mentioned that already, I got lost in all those specs and skipped to the bottom

It runs great! I shot 200rds at first testing, 100 Remington UMC 220gr subs and 100 Fioochie 150gr supers. A few FTE malfunctions at first as I started with the gas choked way down in the key but once it was dialed in (unsuppressed) to cycle subs without locking back on the last round and to cycle supers with full function, it ran 100%. The recoil is snappy with the reciprocating assembly being so light, but the brake is quite effective. With the silencer on I was getting a lot of gas in the face, especially with supers, likely due to excessive BCG speed unlocking earlier while chamber pressures are still high. I plan to further restrict gas so that subs will only cycle suppressed with supers still cycling unsuppressed. That may help cut down on gas blowback but I am not sure if gas-key regulation can do much to cut down on gas blowback since the gas-tube is fully pressurized. Still that setting should be the optimal for recoil and delaying unlock. I'll also look into the RTV mod for the charging handle. This whole set up is fairly experimental: gas-key regulation, ultralight reciprocating assembly on a suppressed .300blk.

Ok.

Those curious of the reference info found in the edited links should be able to find them by googling the thread name and finding its duplicate.

Missed a pic, internals:

A lot of money into this build! Very nice!

Fantastic build!

I had a similar idea of using the same buffer bolt system you used. Figured it wouldn't run, but great job getting that thing to run! This is one of the better threads on ar15.com for me personally. What was the price after everything was done? 4K for the suppressed set up? 3K for the sbr?





EDIT you might want to look into MircoMOA. They have a lopro gas block you can drill to the size you want (or have them do it). It might help with blowback by reducing (as you pointed out) the gas tube pressure.


http://micromoa.com/baby-govnah/



 

Awesome build!!!!  I plan on building a 16" version in 5.56.

Cheers
Shannon

Sweet build!  Gave me inspiration to make the SBR I'm building as light as possible.



All that data should get added to this thread: http://www.ar15.com/forums/t_3_118/638524_Lightweight_Parts_List_with_WEIGHTS__AR_15_.html