Jgun

I have a number of different .308 AR lowers on hand (none of them CMMG). All of mine with the exception of the Kaiser receiver, install the spring and detent for the takedown pins, from the bottom, in the same manner that the selector spring and detent are installed. if your CMMG is the same, you flip the receiver over so the holes to accept the springs/detnts are facing up, you install the pivot pin and selector into the side of the receiver, you drop the detents and springs into their respective holes, and then, press the pistol grip onto the mounting tang of the receiver, being sure to align the selector spring so that it goes into the hole in the grip, and being carful not to bend the springs, but to compress them into the holes. On my Kaiser receiver the takedown pin detent and spring install from the back like they do on an AR 15, but the bore for the spring is threaded and takes a set screw.

I don't know if the CMMG is different than the others, doesn't the takedown detent and spring install just like the selector detent and spring? I find that for the pivot pin detent and spring, I install a pin of the same dia. from the left side, put the spring and detent in the hole, hold them in place with a razor blade, and then push the pin in far enough (from the left side) to hold the detent and spring in the hole, then you just take your pivot pin and push it in from the right side, which pushes the other pin out the left side and captures the detent and spring

In my opinion there certainly is a difference in the fit and finish from one manufactuere to the other. I've also found that there can be a difference between one example and the other coming from the same manufacturer. I don't know how particular you are with regards to upper lower fit, but keep in mind, if you decide to mix and match and you source your upper and lower from different companies, and you find that you're not happy with the fit (but it's still functionally usable) you may be out of luck as far as returning a lower or upper. That's one of the reasons the matched sets are a go way to go. Additionally, I find that the machined billet sets like the MA TEN, usually exhibit a more finished appearence than the forged components. Not that they function any better, just that they are sometimes more finely finished.

Y85, please excuse if I'm repeating info already given above. You are correct in your statement that the MA TEN is only internally compatible with either the DPMS or the Armalite components. The large platform receivers, having no mil spec, are in many cases dissimilar. You cannot put an AR 10 upper on a MA TEN lower, or any DPMS pattern lower either for that matter. You also cannot use a DPMS pattern upper, or MA TEN upper, on an Armalite lower. The parts do not mate up. I personally, prefer a matched upper and lower set when building a large platform gun, but if you wish to have the most flexibility to mix and match uppers and lowers in the large platform, you should definitely go with the DPMS pattern over the Armalite, simply because there are more choices, such as the Tactical machining (TM 10) lower. there are other considerations that you will need to address after you choose your upper or lower or receiver set. We generally advise that if your barrel has an Armalite barrel extension, you should go with an Armalite BCG (or at least bolt) and if it has a DPMS type extension go with a DPMS type BCG. Also, you want to be sure to match your receiver extension length to the type of stock and the buffer you use. You can get guidance for that from Slashes chart on this forum.

I wasn't aware of that. So, the barrel pin hole is drilled through the extension and into the barrel thread eh? That means that if you apply force to the barrel by way of trying to unscrew the muzzle device, while holding the extension with the tool, if the brake doesn't want to give, all of your pressure is applied to the pin. Probably not a problem, and certainly better than holding the upper in a vice block and having the pressure thats applied to the pin by way of the barrel, bearing against the side of the pin slot in the aluminum upper. Probably not a problem, but I would still be more inclined to want to use soft jaws around the barrel near the muzzle device, if that were possible. I guess if your trying to remove a stubbron muzzle device and don't want to remove a full length hand guard, using the tool would be a better option to the upper vise block.

That looks like a good idea, wish they made one for the large platform receiver extension. Only question that comes to mind, isn't the thread for the barrel extension right hand, just like the muzzle thread? Not sure if it should be a concern, but if you were using the device to remove a stubborn muzzle brake, I'm thinking that you could theoretically break the barrel extension free. I'm thinking that for tightening or removing stuck muzzle devices, a set of soft jaws on the end of the barrel, near the muzzle device, might be a better option?

She's a beauty!. Sounds like you've hit on the best way to enjoy building AR's (with someone else buying the part!). You say race gun build, did he have you build it for him for the purpose of shooting the tactical matches?

Are you asking about the bullets specifically? Did you load them the in the 300BLK cases yourself? If not, are they marked as 5.56? Any chance that the bullets are moly coated ?

I'd be interested in hearing about how the red dot location worked for you on the RAMP mount. I just bought one and have not had a chance to try it, but it seems as though the red dot sight is located a little bit off from where I'd like it to be in order to be able to just roll the gun without breaking cheek weld.

Have you ever tried it? Looks like a neat way to have a gun in a bag ready to go, that you would have a second mag at the ready, without having grabbed a mag belt. If you cpould modify it to fit a surefire it would be even better. Question is, how easy is it to grab the mag while the gun is shouldered?

I envy those of you that have partners that share your passions. My girl is from eastern Europe and everything with her is about practicality. I respect that but I'd love to be able to come up with something that excited her, that served no utilitarian purpose, but unless it's shoes or vacuums she has no weknesses. Kind of disconcerting considering all of my personality flaws. On a brighter note she's gung ho with me buying the 5 yr old an airsoft open gun for Xmas. I tried to get her interested in IPSC, but when she found out the cost of ammo she said "are you crazy" hopefully I'll get my match shooting partner eventually. That is of course until he discovers girls.

I was under the impression that the NIB is actually rockwell harder than chrome. And I think that other factors may apply. I have not used any components that have been NIB treated, and that is why I am hoping to hear from members that have used it, telling me that they have 1k+ rds through their guns with no signs of wear. I remember that at one time I was going to install one of the DPMS TIN treated bolt carriers in an AR 15, until I read some reviews from those that had. There where horror stories of Geissele triggers that had the hammers wiped out in less than 100 rds. Of course TIN is not NIB (it's the gold coating commonly used on drill bits and end mill) so maybe my concerns are unwarranted.

I've heard good things about the fail zero (nickel boron). Ive heard that it is very hard and that it is also very slippery, but one thing that concerns me with all of the treatments that I'm considering, is the stories I've heard about excellerated wear on the mating parts, specifically the hammers. I've heard people say that their hammers wore in the carrier contact area in as litle as a few hundred rds. That is on of the reasons that some companies advise that the hammer be treated as well, but I'm thinking that if you treat the hammer then the other untreated mating parts of the trigger will be more likely to wear out prematurely. Not sure how much of what I've read is fact and how much is opinion.

Carbon9, Could you expand on what you have heard regarding the melonite process being performed on stainless barrels? My gun is together (barrel installed) but is waiting for the bolt carrier (just purchased) and a trigger (have not decided what I want for that, probably something accuracy focused, maybe a two stage). I'd like to try the process on a barrel, but my history is that I rarely take a gun apart once assembled, unless a part needs to be replaced, so we shall see if I try out the meloniteing on this particular barrel or not.

So, I was able to pick up an AR 10 bolt carrier to finish my current build, but I had wanted to go with a chromed carrier (had my heart set on the Youngs), so I'm thinking about having the phosphate coated AR 10 carrier, treated with something. I know some of you have used the fail zero, and i think the Melonite has been tried by some. I'm wondering how those that have treated carriers like what the are using? Does anyone know of any companies that will chrome my carrier?

I've installed a couple of them and if I recall correctly, you get a barrel nut wrench and two differently timed barrel nuts when you order the SWS rail. I consider it to be a top of the line rail. Besides the provided wrench, you should also get an upper vise block that allows you to hold the upper in the vise without damaging it when you torque the barrel nut down. The E1 also has a hole in the back that allows you to use a pin to lock it in place radially on the upper but you will need to drill a matching hole in the front of the upper if you want to utilize it. If you go with the E1, I believe that you'll be very happy with the quality. Good luck

Unless I'm mistaken they list the price for the 300 mag at $5699.

Thanks for the lead. I see that they have the phosphate. I sent an email to find out when they expect the chrome ones to be back in stock. Once I get a reply I can decide if I'm willing to wait.

I'm looking for a stripped .308 bolt carrier, doesn't matter if it's Armalite, or DPMS type. Both of them are out of stock from the Mfgs. Anyone know of a company that has them in stock? I'd consider a complete BCG if I can't find a stripped one. Would also consider used. Thanks.

Apparently the gun is a Spikes compressor. www.spikestactical.com/new/z/st-compressor-sbr-556-nfa-p-491.html

Mark, Sorry to hear of your less than satisfying experience dealing with LW. I was researching barrel options for a long range focused barrel in the 22" range. one of the other members posted his range results with the LW Vartac barrel he had purchased from them. I was impressed with the accuracy he had gotten from the barrel, and have other friends that have ordered barrels from LW that are very happy with them. My friends that ordered barrels had waits similar to what you describe (without the order screwup you experienced). I have wanted to try out a LW barrel for a while, but did not like the long wait and high price that I saw listed on their site for a barrel made to my specs. The member told me that the Vartac barrels are stock items. I called up, the barrel was in stock, and was very inexpensive.I had it within a week. The only downside was that the Vartac is 20" instead of the 22" I had planned to order if I went with a custom barrel. I still don't have the bolt carrier, so have not completed the build yet, but, based on my experience, and your's, I'd say that it looks as though they may not handle custom barrel orders quite as well as they do when you order an off the shelf barrel from them.

Out of curiosity, when you lapped the scope mount, did you see any signs of uneven contact that might indicate some misalignment of the mount as machined?

I don't have any info on it yet. As far as I can tell from the video it's just an integrally suppressed DI SBR 300BLK AR. I think that a lot of the amazing ahooting has to be due to the shooter. He's obviouslly got his holdover at that range nailed, and I'm sure it doesn't hurt to have had 100K rds of practice through the gun. just the same thats pretty impressive shooting, and that AR looks like one hell of an effective tool in a very small package.

It looks as though the 300 BLK is capable of making hits at long range (in the right hands) with a suppressed SBR no less. www.youtube.com/watch?feature=player_embedded&v=tgKjbySsAik

Buddy of mine just put a deposit on the LMT .308. It's a monolithic design with a quick change barrel setup, so you can change calibers, and barrel lengths, and they can be had for under 3K.