phunk

how thick is the NiB coating? is it thick enough that if you are going to machine BCG parts, you would need to leave room for the thickness of the coating so that you dont end up too tight?

AHH but i just noticed the 20" is a 1:12 twist... i was thinking i wanted a 1:10 if i wanted to go with heavier rounds for long distance accuracy. unless i am wrong in my thinking, which is possible cause im a 308 noob, i am sort of failing to see the point of a long barrel without the aggressive twist

FA also has those Criterion barrels in stock in 20" stainless. they are a little longer than i wanted, but stainless and heavy barrel are 2 points that i was looking for. i might have to settle. I am sure I could knock off 2" from the barrel some day if I found it bothered me, just would have to get it crowned again, right? Any other harm in doing that? I see the 20" one has a rifle length gas system. I have a lot of learning to do about the pros and cons of the different length gas systems, and I assume if you shorten the barrel too close to the gas block, the projectile will have left the barrel before enough pressure was spent to cycle the action? am i correct with that assumption?

thanks guys i will research both those options. i wish i knew more about it so that i could just quickly pull the trigger and order if i knew it was what i was looking for

I am most concerned with accuracy, not too concerned with weight. I want an 18" barrel. I was looking at the Rainier Arms UltraMatch, but they are out of stock and have no guess when they will have more, but they say it could be months. So, they are no longer an option. I want to use my rifle this summer. I will be ready to purchase a barrel in roughly 2 weeks. Where would be my best bet to get one ordered and actually see it within 4 weeks? How long does Kreiger take to get a barrel done? This will be my first time purchasing a rifle barrel without an entire rifle, so I am not too familiar with who makes the better ones.

I'm familiar with the 223 and 556 chamber from owning and researching that for a while... The 308 stuff is what's new to me. It's a lot harder to find solid information but I think it's starting to come together. I do need to choose a chamber so I can order a barrel soon. But either way your post is a good summary for those chambers. One thing I would add that answers a question I had.. From the research I have done, all ammo manufacturers manufacture the physical components for 223 or 556 exactly the same, and the only thing they will change is the powder load. If that isn't accurate let me know, it's just what I have read, not something I have confirmed with my own measuring.

ya i was googling that, trying to figure out what a Wylde chamber meant as far as 308 goes, and couldnt find anything yet. So I assume the guy at RA must have thought I was asking about a 556 barrel, even though the subject title was "308 Barrel" lol. I had never heard the term used for a 308, which is why i said "apparently", but i wasnt going to argue with him being as new as I am to 308 AR

Great looking rifle. I am curious how that barrel will perform for you. I was currently eye-balling the RA UltraMatch myself, in 18". I asked RA how it would compare to the Noveske and they told me they are just as good as one other, and that I just had to decide which chamber I wanted (Noveske = NATO, RA = Wylde, apparently).

eh too late to worry about it now anyway, the bolt is sold out

I saw that on slick guns. I don't know... I told the girl at SI-D that I would order one of their nickel boron bcgs when they are ready to ship my receivers. But at the same time, if I just grabbed the DPMS, I could send out the bolt to get my barrel/extension made and headspaced. The SI-D one doesn't cost much more, I don't know if its worth the difference or if I'd be better off grabbing a DPMS while it available.

Here I have attached pics of my sig m400 for comparison. Without bright light source behind it, looks great. With a flashlight, I can get light thru anywhere from the receiver extension up to the ejection port door

Today I ordered a Magpul UBR stock. I see mixed reviews on it, but I actually just like the look of it, and ill give it a shot and see what I think of it. It comes with the receiver extension too which is convenient for me right now. I suppose that means I should start searching for my ideal buffer and spring. A quick glance led me to Heavy Buffers products that are in stock at Brownells, but I should read about it more. What forum section is ideal for a build thread once I start one?

ah, that sounds like it might not be correctable without replacement. without having it in front of me, i have hard time deciding if its enough to bother me if it were mine. with most, if not all, of my guns, you can see light between spots of the slide/frame, and my SIG AR15 i can see light between the upper and lower.

a Sig rep was at a LGS grand reopening here last Saturday. I asked him if he knew when they would start shipping, and his reply was "thats a good question!" i wonder what the deal is with the one that I saw on gunbroker.

Once my 308 AR exists, I will post up when I am looking to take it out shooting.

First I would figure out the source of the gap, and see if I could fix it myself. What do you think is creating the gap? It would be either the take-down pins location in reference to the mating surfaces is slightly off, so the surfaces are not accomplishing full touch-down.... or what I would suspect is much more likely, there is an extremely minor mismatch in the radius of the mating surface that curves upward near the buffer. I would suspect that they are touching in that spot before the flat area can touch-down fully in the rear. A radius like that, is going to be a pain in the ass for manufacturing a clean mating surface, and the tighter you want them to fit, the harder it will get to make them fit right. Sometimes even miscalculating the thickness of the material finish can take a perfect fit pair of parts and make them a no-go. With the front take-down pin already installed, does the rear take-down pin feel like it requires any extra effort to insert? If you have only the rear pin inserted, and the front pin out, can you make them sit perfectly flush holding them together? Then lastly, with no takedown pins in, can you make them sit perfectly flush?

I am sure you are all well aware of this rifle. http://sigsauer.com/CatalogProductDetails/sig716-precision.aspx I have been looking at that page for months, but the rifle seems unavailable, even if you were willing to pay a premium. 2 weeks ago I saw one listed on GunBroker... I dont know if it was real or not but it went over $3000. Has anyone seen one in person? Being a Sig fan, and loving my Sig AR15.., Every time I pay my credit card down to zero, I look and see if I can find one of these somewhere. Then nope, so I buy other toys and check next time. Admittedly, I have not spent appropriate time investigating other manufacturers for comparable offerings in 308 AR. Most my research has been spent in investigating my own build.

thanks for the link, it looks like a nice place and not too far from some friends in new berlin!

thanks. i might end up in Indiana to take this rifle out shooting when im done with it! There is hardly anywhere near the chicago burbs to enjoy it.

Sorry to bump an older thread... Anyone put any orders in with DSG Arms lately? From the link in this thread I noticed they will still take backorders at $20 each. Do they charge your card when you order, or when they ship?

Thanks guys. Yes I agree and I won't over pay. I did find a local MATEN upper for $350 with a new PMag included. I might pick that up too. Between the SI Defense lower ill have, and having a MATEN upper, I should have all the dimensions I need to build my own lower for the MATEN. I work in product engineering and CNC machining and injection molding. I almost tried the receivers on my own, but I only found a CAD file I trusted for an Armalite lower, and it was the older one that didn't take PMags. I could not find solid enough information to come up with the dimensions I needed to tackle the project without endless engineering and needing all the parts that go inside it first.... Wasn't worth it versus 500-600$ to just buy the stuff. Is it weird that I really like the looks of the angle in the receiver mating surfaces just in front of the buffer tube on the armalite and mega? I don't know, I just think it looks cooler than the DPMS and AR15 curve there.

Just wanted to say this website has been a great resource for my research the last few months. So thank you to all you who contribute to the useful content here. I have come back to this website several times while trying to make decisions. My only AR is an AR15, and its a Sig M400. It's got the typical Magpul furniture trend applied to it, but mechanically stock. I have decided that it performs to my expectations reliably and I will leave good enough alone. I don't know who makes the barrel, but with lake city xm855 it groups an inch at 100 yards with an eotech and 3x magnifier. I believe the 1:7 twist will do even better with the 75g hornady stuff I have waiting for spring. So at any rate, I'm very pleased with it. Now I want to reach out further, and tighter. I think more can be squeezed out of the AR15 platform, for sure... But not for me. I have this weird thing where I have to assign all my firearms a role, or a job description. Even though the only roll they will ever truly play is target shooting, it's just the way I work. So I cannot alter my AR15 to fill this other position I have, because it won't do it as well as a 308AR, and it won't be able to fill its existing roll as well after such changes. I've spent some time trying to decide if I wanted to build or buy. If I bought, I would wait to get my hands on the new Sig 716 Precision model, but they are not out yet, and in this climate I expect will sell for over $3000 if they hit the streets soon. I was looking at Mega receivers for a while, but I don't feel like paying that type of money on gun broker and they tell me they are back ordered over a year which is a really ridiculous thing to say to a customer. Sounds like someone needs to buy another CNC or outsource some machining. Yesterday the SI defense sets caught my eye, and I ordered from them directly. They gave me an estimate of 3-4 weeks. I hope it's not much longer than that, I am excited to get started. I always have a lot to say so I apologize in advance for that.