Glockslap

IIRC my barrel cost $220 dollars +/- The CF barrels are cool in concept, but I had heard a few things that scared me as well as the price. The 18 inch pencil .308 weighs under 2 lbs. Not much in that caliber is lighter, regardless.

Not many. Probably a few more to sight it in, then test it for final accuracy. I like it because it is fully functional for hunting, predator defense, and if I stumble onto some ne'erdowells a couple of 20 round PMAGS of .308 is a comforting option.

Mine is still significantly lighter; that weight of theirs is w/o optics/sights. And go price it :'( I was looking at those barrels HARD. I think my rifle has got roughly $1500 in it, including optics and mounts.

http://www.ar15.com/forums/t_3_121/610941_.html&page=1

http://www.ar15.com/forums/t_3_121/610941_.html&page=1

UPDATE: Please note that the forward assist and dust cover do not work with the JP lightweight bolt.

Yes the P-barrel is very thin, and light. Chopping off four inches and welding the A2 FH for a still 16 inch legal barrel would lighten the gun a bit more, and the adjustable gas reg still make her work. Still, it being a .308 set up for the woods, I want the round to have enough poop to zap anything on the map that says 'Merica <thumbsup> (with the right bullet). Recently picked up a lightweight scope, now waiting for the rings, and from there I will give you boys the final "wet" weight with a load of five 168's in her (and 20 for grins). Once all put together, I will strive for "true" 100 yard "first round" accuracy with a five shot 168 match ammo group, to include barrel cool down sessions and bolt tensioned for each shot against a four round magazine. Follow up accuracy will be a 5 round group in maybe under 30 seconds (timed) just to show how the barrel works under heat stress.

I just noticed my shoulder is a little tender today, lol...

Thank you! I am sure, some manufacturer will take my lead some day :o 5.56's IMHO should weigh 5lbs, and the 7.62's 7lbs...

Finally <munch> http://308ar.com/forum/building-a-308ar/lightweight-308-ar-complete-with-range-report/

Lightweight .308 AR completed, with range report... I'd like to thank those of you who have waited patiently while I completed my project. <munch> My goal was a fully functional, 7.62 carbine that weighed well under 7lbs w/o a magazine or sights. I'd say my goal was achieved at just under 6 1/2 lbs 8) Again, this is a fully functioning semi-auto rifle with a full 18 inch barrel, A2 flash hider, and forward assist (non-functioning due to lightweight bolt; I may add a dustcover later). Obviously, a few more ounces could be shed with a 14.5 pinned, or 16 inch barrel, but at the cost of velocity-and I want this to be a hunting piece capable of getting 97% of what the caliber's velocity/energy has to offer. Dressed, with an empty 5 shot magazine, Aimpoint Micro, and highrise mount, she still checks in at a svelte 7 lbs 1.5 ounces (w/o ammo), which is the configuration I range tested with today. [img width=810 height=473]http://i154.photobucket.com/albums/s248/miamidave101/20121216_125321-1_zpsaeada045.jpg [img width=810 height=607]http://i154.photobucket.com/albums/s248/miamidave101/20121216_124819_zps4566eb61.jpg Prior to range time, I cleaned the barrel (very dirty!) and lightly oiled the bolt. Adjusting the JP gas block, I fired several rounds to fine tune it. I figured mil spec 145 FMJBT South African 7.62 surplus would be the lightest load ever shot through it, and subsequently noticed it needed a bit less gas as it broke in further. Playing around I found what I felt was the "sweet spot" and after 30 rounds of the SA started running some heavier factory soft points that were loaded much stouter than the SA. Once gassed correctly, it stripped and fed all rounds from a full magazine without a hitch, solidly locking the bolt open when empty-both from the bench, and standing (different recoil impulses from each). I did not bring a 20 round magazine, but I have no doubt it will run the same. Throwing on the unsighted Aimpoint red dot just to get some "go-by" groups, generated the following from a seated rest (no sandbags). All 5 shots were fired relatively quickly-roughly 5-7 seconds apart at the 25 yd line: I expect that group to get slashed SUBSTANTIALLY with a magnified optic, decent trigger, some barrel break in (50 rounds today), sandbags fore & aft, and waiting for the barrel to cool down. The pencil barrel starts to heat up pretty quickly... Overall, with the above mentioned I feel it has the potential to easily be a solid 2 MOA gun with most ammos, maybe even less than 1.5 with match? Compare it to a DPMS 7.62 AP4 16 inch barrel (carbine gas system): Recoil? Not even remotely harsh and way far from punishing. I feel an 8lb semiautomatic 12 gauge with birdshot kicks substantially more. One person at the range, who had never fired a .308 before, commented on it being a pussycat-not much more than his 5.56 experiences. I'm guessing it has everything to do by not being over-gassed, the lightweight bolt, and mid-length gas system all factoring in to it's performance. I can't imagine what it would feel like with a compensator on it-but again-not this thing's purpose. Eventually I will add an optic that will weigh in at around a pound, and a sling, making for a loaded (5 rounds) package a bit over 8.5 lbs, making it a pretty handy walking around the woods gun in just about anybody's book. It will also handle almost anything on earth, especially with the capability of charging it with some fully loaded 20 round magazines as backup <thumbsup> Anyway, thanks for stopping by. Here is the link to the original thread for reference: http://308ar.com/forum/building-a-308ar/build-a-light-weight-308-ar/

Sorry guys, I've been out of the game for a while, and had an issue with the upper/lower halves fitting properly, causing me to hand sand the rear receiver pin >:( Anyway, looking to get it buttoned back together, get the gas adjusted, and give you all the final weight and function check. I really do apologize it has taken so long.

Thanks-had it cut at a golf shop. Came clean, albeit a little short (2mm)-but no biggie. At the very least, it is not touching any part of the block and gives it a little more room to "breathe." Still protects the gas tube. Going to *try* to shoot it this week-but no promises. <munch>

Well, here it is, I finally received the Gen 3 SI Defense upper receiver, which checked in at just shy of 12 oz w/o dust cover and forward assist). I have 2 more mods needed, which should shave another 1-2 oz (lighter pistol grip, cut carbon fiber hand guard to mid length specs) I'll have pics up when completed. It is looking like 6lbs, 7 oz w/o sights and ammo. That is with the 18 inch barrel plus flash hider. I can't wait to get this dialed in <thumbsup>

Well still waiting on the lightweight upper, so I won't know till I way it. But the full length carbon fiber handguard I ordered came in, weighing 2.6 ozs heavier than the carbine length. Once cut down, I'm hoping for only a 1-1.5 ounce weight penalty to cover the gas tube safely. Remember, my LW barrel is a midlength, so neither here, nor there <dontknow> lol. Any hints on cutting carbon fiber :o

It would be nice if those plastic sights would bolt on clean <thumbsup> and no I didn't know that, so that would be a big plus. It's looking like a 6lb 8 oz gun w/o sights and mag, and IDK if I can scare a few ounces off w/o chopping things further. I thought about cutting/cheesgrating the magwell box, or drilling holes in the charging handle. I feel like I want 6.5 lbs with the sights, but again, the key will be the upper receiver weight. We shall see.

Well that is a good question, since most folks don't care about muzzle flash on a traditional hunting firearm, and 18 inch/.308 has almost fully cooked all of it's powder. For me, I wanted to keep somewhat with the tradition of the rifle, it *may* reduce some muzzle climb, and the fact that I may consider using it with night vision-as well as the unlikely event I ever had to go defensive with it. But I could definitely save another 2 oz there, and another 1-2 oz by chopping the 18 down to 16. All in all, my only penalty (hopefully, slight) will be going to a mid-length gas system (I've already ordered another carbon fiber tube, which will need to be cut down from rifle length to mid). Hopefully, the slight weight penalty will also help mitigate recoil and pressure to compliment the adjustable gas system. I think I need to do something about that stock though, and I don't want to add more weight to it, since "irons" will add weight. I have some ideas, but we'll see... Wouldn't it be a hoot ?- It weighs like a 5.56, kicks like a 6.8, hits like a .308? 8) I've already had several people say what I am doing is not possible (not here), which I find, well you know-pretty possible <laughs>

6lbs 11 oz even with the new 18 inch barrel with hider on it. It weighed 1lb 15.4 oz (and ounce lighter than advertised). So all I need now is the LW receiver + a few other things, but as it stands now it is 6lbs 3.4 oz with sights. Pics tomorrow <thumbsup>

The FSB is lower than the rear upper rail. I may need a rise, or taller FSB. Further, I saved potentially another ounce with a Magpul grip. I will have the model later. My 2lb 18 inch barrel arrives today, and I have been told the SID uppers should be available next week. I'm hoping for at least another 10 ozs off this rig :o

No worries J-Gun! But FWIW, the CF Tube and barrel nut are $100 (carbine) and $120 (rifle length) so as comp stuff goes, I think it is pretty reasonable. Just weighted the MagPul pop up sights sights, 2.4 oz...for both ;D

I will be adding a more substantial stock, or find another commercial type stock and modify it. That little nub is uncomfortable even on 5.56's as mentioned. 7 ounces is guaranteed off of the barrel, whether I keep it at 16 or the 18 that is on its weigh. the SI upper should net some more weight off too. My dream is begining to come true ;D I just picked up a set of Magpul plastic pop up sights, and will be weighing them later. Again, this will be a carryin gun, but I am sure once she is broken in, it will suffice as a "balloon up" situation as well. It should also be pretty well balanced, since the weight has been removed equally, if you look at the numbers. As it stands now, it feels GREAT ;D Not sure about the "cheating" with the CF tube means?

Even w/o the barrel and lightweight receiver, she still pretty svelte ;D You can't see the "7" in front of the 3.2 oz part. So 7lbs 3.2 oz.

Still Waiting for the lightweight upper. It seems NEMO and SI Defense are...well, doing something different? As it stands now, I just purchased an 18 inch barrel weighing 2lbs .4 oz ;D So my net weight loss is the following: XM177 Stock -4.0 Bolt -4.0 Handguard -7.0 5.4 oz Barrel -7.3 A2 F.H. -.5 LW Upper -3.0 (based upon what they have told me, but still a wild card). My total weight loss would be 24.2 oz. Please fee free to check my math :) It's looking like this rifle will weigh about 6.6 lbs without sights or magazine.

Jusr weighed the A2 flash hider (FH) w/o the washer...1.8 oz, so just .5 oz lighter :'( was hoping for a full 1 oz lighter as reported (maybe of a 5.56?), but oh well. I wonder if the dpms factory FH offers more accuracy? I guess I will go with the A2 FH for now, it's also a bit shorter in length, and has more of a muzzle break look to it (no slots under it). Still waiting several more weeks to go for the Gen 4 upper receiver from NEMO

Sorry, FH= flash hider, CF = carbon fiber; apologies if I don't always spell it out guys-