User Panel
Quoted:
Started building a lightweight AR and finding specs isn't always easy plus are they true or not?? So I wanted to jot down my findings for others. Plus I'm a weight nut, comes from bikes and cars. This build is just what I can afford and what I want. I know I can do lighter. Lower.... Anderson lower, typical, nothing fancy- 8.68oz CMMG lower parts- 2.00oz PSA mil spec trigger and pins- 2.53oz ATI buffer tube- 3.47oz ATI castle nut- 0.52oz ATI end plate- 0.49oz ATI buffer- 2.95oz ATI spring- 1.85oz MFT stock- 6.02oz, 5.8oz advertised MFT trigger guard with roll pin and front allen screw- 0.20oz MFT EPG16 gutted grip- 2.24oz, 2.4oz advertised with insert, roll pin and trap door Magpul 1/4-28, 1" grip bolt- 0.23oz Total- 31.18oz Actual weight on my scale- 31.24oz probably from oiling? http://i1064.photobucket.com/albums/u362/scott_thomas7/IMG_3373_zpsj4unnhbk.jpg Some upper parts on the way, will weigh later Upper.... Faxon 14.5" pencil barrel- 18.4oz advertised, 17.5oz online source Faxon QPQ LWT BCG- 8.5oz advertised 2A Armament BALIOS lite upper- 5.85oz advertised 2A Armament 10" keymod rail with "upgraded" aluminium barrel nut- 6.35oz advertised V Seven titanium 0.625" gas block- 0.68oz advertised Strike poly dust cover- 0.3oz advertised Charging handle- 1.07-1.12oz from other guns at home Mid length gas tube- 0.64oz online source Gas tube roll pin- ??? Precision Armament M4-74 silver comp- 2.67oz Crush washer- ??? Magpul flipup sights- 2.47oz Total- 46.03oz View Quote We think you are doing nicely. ;) |
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syno: You are doing great on the upper half, but the lower assy is way too heavy IMO. It needs to be closer to 20 oz. Check out the combination receiver extension/fixed buttstocks from Smoke Composites. You give up the length adjustment, but my carbine sized model weighs only 4 oz. Add to that a 1 oz buffer and reduced strength spring from Taccom. Also, with the reduced mass in the carrier and buffer, you need adjustable gas to keep the bolt speed down. I like the adj. gas blocks from SLR and the adjustable gas keys from Rubber City, take your pick. The keys are cheaper but the gas blocks are easier to tinker with. good luck - CW
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Everything is bought at this point so I'm going to have to play it by ear and see what happens. Again I just wanted a rifle under 5lbs and what I could afford buying here and there so that's where some of these parts came from. Barrel shows tomorrow so we'll see what my weight is!
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Well you're under 5lbs w/o sights or mag.
You can always add lighter parts down the road and of course the removed parts will be the start of another build! That's the rules. |
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Quoted:
Updated the list with the first batch of parts that arrived. Pretty happy with some like Faxon that came under what's advertised but the others were over. The Faxon stuff is awesome! The BCG is crazy light! Should still be a sub 5lbs rifle though. Also the total length looks safe at 16.75" with the comp I chose. Faxon 14.5" barrel- 18.24oz, 18.4oz advertised Faxon BCG- 8.48oz, 8.5oz advertised Vseven Ti gas block- 0.68oz, with 3 set screws 0.71oz, 0.68oz advertised Gas tube with roll pin- 0.76oz Strike poly dust cover- 0.40oz, 0.30oz advertised YHM crush washer 0.11oz http://i1064.photobucket.com/albums/u362/scott_thomas7/image_zpsj70cu5gx.jpeg http://i1064.photobucket.com/albums/u362/scott_thomas7/image_zps24hgtvbs.jpeg http://i1064.photobucket.com/albums/u362/scott_thomas7/image_zpsrhbsfxfc.jpeg View Quote |
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Quoted:
Thanks. How confident are you your barrel and BCG don't need headspaced checked? View Quote However, we will ALWAYS recommend someone check unless it was checked by us and laser serialized. Its a 60,000 PSI explosion next to your face and its not worth any chances at all. |
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OP: That's a nice setup so far. Here is my lightweight (not ultra LW) range build so far at 4 lbs. with MBUS, but without mag, but I'll be making changes this weekend:
Faxon 4150 QPQ 16" mid pencil w/ thread protector AIM Surplus low mass BCG (8.9 oz w bolt) Superlative arms .675 adj. gas block Aero Precision standard (not M4E1) upper w/ FA and door (blem) Aero Precision 9" MLOK guards with their barrel nut (blem) Magpul MBUS v2 sights NFA poly lower with NFA steel/poly LPK pre-installed Carbine buffer tube with standard spring, castle nut, end plate MFT minimalist stock 1 oz empty buffer with single alum. weight Last weekend, I put 200 rounds through it, with 5 different types of ammo (55gr and 62gr), including Tul and Cabelas "Hipshot" and tuned the gas block to cycle all. Works great, no FTEs or short stroking. Changes coming up: I have a lighter DSA lightweight upper coming, that should be 5.8oz. I'll have to go back to my notes, but that AP upper was not very light, over 8 oz I believe. I'll also be replacing the AP 9" guards which don't cover the gas block with 12" guntec handguards with alum barrel nut that weigh about the same as the AP 9" I'll be replacing the lower NFA lower with a Mag tactical lower with either CMMG or Anderson LPK to start with. This might add some oz, but I might be OK, even if the weight goes up. I have a < 2 oz muzzle brake, but the lwbcg, low weight buffer, and adj. gas, I have it tuned to feel like a 10/22. I'm concerned the muzzle brake would add blowback to my fellow range folks. Probably have about $700 into the way it is now, have avoided any exotic pricey V7 parts so far, but might look into their end plate or parts that give the most reduced weight value. |
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Ok everything this here, let's finish this!!
2A Armament 10" key rail with titanium nut/ rail- 5.28oz, nut 1.80oz, total- 7.08oz, advertised- 7.00oz 2A Armament aluminium barrel nut- 1.13oz, adertised 1.10oz 2A Armament lite BALIOS upper- 5.79oz, advertised 5.85oz LBE charging handle- 1.12oz Pics to follow!!!! |
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Looks good.
Thanks for the list. Even though my parts will be completely different, it's always helpful to see what parts were used. I'm building a lightweight for my wife but I don't have the income to match my desire to build these rifles, so mine won't be anything exotic - just "lighter than average". The barrel weight is a huge factor and I'll also be using a Faxon pencil barrel - I'm still undecided on the length. 16"? 14.5" with my own muzzle device pinned? One of the Faxon 14.5 with slim, pinned muzzle device? I'd love to try the new Faxon pinned comp barrel, but I don't know how effective it is. Since I'm building it for my wife, the effectiveness of a comp/brake is more important than if I were building it for myself. Anyway, other than the barrel, my only other "light" part will be the one piece lower/stock in the form of a GWACS CAV-15 "polymer" lower. They say that once the LPK, buffer and spring are installed, it's a full pound lighter than a "standard" complete lower with stock. I have an Anderson Sport upper with no FA or dust cover. I have the LPK and buffer/spring to finish the lower. All I really need now is the barrel, purple ALG Defense hand guard, and a BCG (considering the AIM lightweight BCG) Shouldn't be too long now... |
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Update
Decided once again I do not like the Magpul MBUS flip ups. Went with the Vortex Venom red dot instead which comes in at 1.61oz with mount which saves 0.86oz over the flip ups. Total upper now weighs 46.34oz which means the steel pin and weld added 0.04oz. The AR now weighs 77.58oz or 4.85lbs. |
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Quoted:
Very. By our tolerance allowances, I know that you will be in the "Go" range. However, we will ALWAYS recommend someone check unless it was checked by us and laser serialized. Its a 60,000 PSI explosion next to your face and its not worth any chances at all. View Quote |
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Nice pair of builds. 1 rifle, 1 carbine. That's how I jumped in, I bought a pair myself.
Not bad shooting at all, first time out. Good results with no major problems to report that's excellent. -CB |
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Quoted:
Nice pair of builds. 1 rifle, 1 carbine. That's how I jumped in, I bought a pair myself. Not bad shooting at all, first time out. Good results with no major problems to report that's excellent. -CB View Quote |
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synolimit,
Your hammer spring is installed backwards. Yes, a carbine is usually a shorter barreled version of an existing rifle. Not always. For Ar-15's the collapsible or fixed stock is a quick indicator. The gas system length, carbine midlength or rifle isn't usually a factor -CB You made the right move using midlength gas system with a lightweight build. Midlength gas is a little easier on the gun/parts. A carbine gas system may have over-gassed it. ETA: Take a look at your trigger spring too. One leg of the trigger spring (on the same side as the magazine release button) looks bent as if it's going upwards. Both trigger spring legs should be under slight spring pressure pushing down on the fire control pocket floor. -CB |
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Quoted:
synolimit, Your hammer spring is installed backwards. Yes, a carbine is usually a shorter barreled version of an existing rifle. Not always. For Ar-15's the collapsible or fixed stock is a quick indicator. The gas system length, carbine midlength or rifle isn't usually a factor -CB You made the right move using midlength gas system with a lightweight build. Midlength gas is a little easier on the gun/parts. A carbine gas system may have over-gassed it. View Quote |
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Okay. The hammer spring looks good to you. Unfortunately, it is installed backwards. Might I also kindly suggest you promptly pay a visit to your optometrist? As stated in my post above, the trigger spring looks suspect as well. And I also think it's possible your Magpul MBUS sights are counterfeit copy's not fit for use on firearms. Take it for what it's worth, free advice it didn't cost you anything. Still a nice build. Have a great day. -CB
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You may be interested to know there is a thread on this form specifically dedicated to listing lightweight parts and their actual weights as measured by users:
Lightweight Parts List with WEIGHTS Quoted:
Umm looks correct to me. And yes it's mid length. You just called it carbine length so I was trying to bring light to that. View Quote noun a light automatic rifle. historical - a short rifle or musket used by cavalry. He was referring to the actual rifle, not your gas length. Your hammer spring is definitely on backwards Also just FYI in case you didn't know, the way overall barrel length is measured is from the face of the bolt when it's in battery, so the barrel extension is not included in that. |
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For those looking to build lightweight carbines, Faxon has the pencil and gunner barrels 20% off during the NRA show.
Put it in your cart and you'll see that a 16" pencil barrel is only $140. (shipping for me was $8 for 2-day shipping) |
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