Phil3

I am the OP. I did e-mail Compass Lake about creating a 6.5 x 47 barrel. They replied and said they do not chamber in 6.5 x 47. Oh well. Krieger will chamber in 6.5 x 47. Contacting them with a few questions. Phil

I sent an e-mail to Compass Lake, with all the specs and requirements I thought they may need. I can provide them the brass and the Armalite bolt carrier group for proper fitment. One thing I thought of that I am unsure about. The Lapua brass uses small rifle primers. I do not know if that may pose any problem with the Armalite bolt firing pin. Phil

I have a box of many AR-10(b) parts which I stopped building from when CA made building what I wanted illegal, but now, I have moved out that state and CAN build what I want. So, I am resurrecting my AR-10(b) project. One thing I do need is a barrel, but would like to get something chambered in 6.5 x 47 Lapua. Are there any known (or possible) issues using this cartridge? Note, this cartridge uses a small rifle primer. Krieger will make me an AR-10 barrel, chambered in 6.5 x 47, to the length and contour I want, but am fuzzy on what can (or should) be done with regards to chamber dimensions. For bolt guns, I sometimes use a custom reamer for chambering, but something tells me I best stick with SAAMI spec chambering on a semi-auto. I would also like to know how harsh the AR-10 is on brass, since the brass I will be using is pricey Lapua. Lastly, will I need to do any tuning of the gas system to work with this cartridge. The bolt carrier group is Armalite, as is everything else, except the lower receiver (Noveske N6). If anyone wants to know why I am choosing the 6.5 x 47 Lapua, I can explain that. Thank you, Phil

Hi, I am definitely biased toward the 6.5 x 47, and while I have some specific technical reasons why, I would not be honest if I did not say, I just like the round, and find myself rooting for something different. The 6.5 x 47 is that in the semi-auto world. I built an AR-15 shooting 223 just to see how accurate I could make a semi-auto, and it was fun to out-shoot some bolt guys with regular 5 shot groups under 1/2 MOA at 100 yards, off a bipod. I want to see what I can do with the AR-10, and this time, using a cartridge not often seen in semi-autos. I will be leaning on you guys to steer me in this build. I have some good components already in, but have important decisions to make on other parts. Phil

Thanks for tips on reloading. My reloading equipment is good quality and complete, so I think I am well positioned to take best care of the cases. I use Quickload software, chronograph, along with visual inspection to avoid excessive pressure. If I can get 15 - 18 reloads out of brass, I will be quite happy. I will be using a Forster Co-Ax press, and most likely Forster dies. A friend has an annealer and he will anneal cases for me as I require. I will see if I can determine the reamer used to cut the chamber, or at the minimum, have a full length die honed in the neck area to resize the neck to the exact size I want for desired neck tension (.002"), negating the need for an expander button, while also maintaining proper neck clearance in the chamber (.003"). I do not want a loose chamber as the neck will expand excessively upon firing, working the brass, hence my desire to know reamer dimensions. From what is said here, it seems like my Lapua brass will have a decent life in the AR-10 and helps with my worry over the gun beating it up and forcing frequent buying of new brass. I am after accuracy, not ultimate velocity and do not expect to be pushing pressure limits in the pursuit of velocity. The brass for the AR-10 will only be used in that rifle, not my bolt gun. I have some questions on proper gassing of the system, with regards to barrel length, gas port placement, custom barrel extensions, buffer components, etc. For another thread. Thank you. Phil

I have considered the use of the 6.5 x 47 vs 6.5 CM in both my bolt gun build, and for this AR-10. I think the 6.5 CM is an excellent round, but a number of things, however minor, once all added up steered me toward the 6.5 x 47. It does have some negatives, as does most any cartridge. I can share the pros/cons if people want, but not here to cheer lead for the 6.5 x 47. The 6.5 x 47 brass can be had for as little as $1.03 a case, up to around $1.20, from what I saw today. Thanks for the article. I have read that multiple times. Perhaps my biggest challenge will be building the AR-10 in an acceptable way that still meets California restrictions. My biggest issues are the pistol grip and stock. More on that in another post. Phil

Thanks for the comments. I would like to ensure the gas system and BCG are cycling properly (proper parts and design) so as to avoid eating expensive brass. I may ask for some advise on that. It should be an interesting build, although cannot be exactly what I want because I am in California, with some quite absurd restrictions. I got some parts 9 years ago, so it will be kind of a retro build (Armalite AR-10b). Phil

I am the OP. In answer to questions... I am building a 6.5 x 47 bolt gun AND a 6.5 x 47 AR-10. That was the plan, unless the AR beats up pricey 6.5 x 47 Lapua brass (hence my question) at a rate that becomes unacceptably expensive. The 6.5 x 47 Lapua brass can last a long time in a bolt gun, no worse than anything else, but its max pressure is 63,091 psi, which is slightly higher than the 62,000 psi for 308 and 6.5 Creedmoor. As such, the 6.5 x 47 Lapua can work the brass a tad harder. I do not know how much brass life is shortened in a semi-auto vs a bolt gun. Knowing that would certainly help. I would keep the brass for the AR-10 separate from that of the bolt gun. I will be using a custom honed full length sizing die for each gun and the brass that it uses. This will minimize working the brass and prolong brass life. I will also be annealing the cases every few rounds to further extend brass life. I have no desire to load to high pressures, so hopefully that will help with brass life. At around $1.20 each for the 6.5 x 47 Lapua brass, I cannot afford to have cases ready for the trash after just a few uses. If the AR-10 eats cases for breakfast, I will need to move to another caliber where cheaper brass is available (6.5 Creedmoor, 308 Winchester, etc.). Thanks, Phil

I wish to use the 6.5 x 47 Lapua cartridge in the Armalite AR-10(b) I am building. However, that cartridge only comes with a small primer, not "large". Will this present any problems with the AR-10? For those who use the 6.5 Creedmoor with small primers (available in small or large), have you had any issues? Thanks, Phil

I am building an Armalite AR-10(b) rifle and was wondering about brass life. I ask because I wish to use the 6.5 x 47 Lapua cartridge, which I will reload. The only brass is Lapua, which is expensive, so if the AR-10 tends to beat it up badly and give me short case life, I may have to move to a cartridge where there is cheaper brass (i.e., 6.5mm Creedmoor). I would likely have the barrel chambered by Krieger to fit my bolt and upper receiver (Armalite). Thanks, Phil

Brand new here, and hope to learn more about the Armalite AR-10. My proposed build is in the thread below. I have successfully built an AR-15 on which I tried to obtain best accuracy and hope to have the same success with the AR-10. Not 100% sure on using the 308, but 260 Remington won't do much for me unless I drive two hours to a longer range. Otherwise, it is 200 yards max in the San Francisco bay area. Expect I will learn more here, and with time Hope I cana help out others when my AR-10 is firing. - Phil http://308ar.com/forum/index.php/topic,1208.0.html

Hi, Brand new here, and after building one AR15, am now looking to build an Armalite based 308 semi-auto (AR-10). Would like some suggestions on my planned components for my intended use. This will be mostly a bench gun, as the area I live in (San Francisco bay area) does not offer much in the way of other shooting venues. Besides, I like trying to eek out the most accuracy from a gas gun. Probably will use 308 vs 260 Remington given limited range I can shoot to. Besides, the longer barrel life will be nice. Anyway, here are the parts. * = I have already. - Phil *Noveske N6 lower receiver *Armalite magazines Armalite lower parts kit Geissele two stage adjustable trigger *Armalite bolt assembly *Armalite charging handle MagPul PRS stock (w/Armalite buffer, spring) *Armalite upper receiver (no forward assist) JP Rifles handguard Krieger 22" .920" muzzle diameter stainless steel barrel. 1:11.25 twist 308 cailber Evolution Gun Works clamp on style gas block Ben Cooley muzzle brake Burris PEPR one-piece scope mount Scope is undecided.