Jgun

I'm looking for a Knights URX 3 (8") rail, in excellent to new condition. If anyone has one they want to get rid of, or if anyone sees one for sale someplace, please pass it along. Thanks.

OK, please bear with me if I've got my facts mixed up. As I understand it you are taliking about a JD upper (of which I have not worked on). I may be mistaken, but as I remembered it, DPMS raised their rail not lowered it, but I could have it wrong. I recall buying one and it being high and having to locate an older upper to complete the build. Now, the way you are measuring may not be the best way. All of the DPMS pattern uppers should measure the same from the center of the BC bore to the mating surface of the upper/lower. Where they will vary will be from the BC bore to the top of the rail. I do not have the exact measurements but I saw a tutorial on one of the handguard Mfgs site's where they told you to measure from the top of the rail to the surface of the upper where the charging handle mounts. I thought that on the older DPMS pattern uppers this dimension was be smaller than on the newer DPMS uppers. the point is that the relation between the barrel bore and the location of the trigger have not been altered (and are the same between Armalite and DPMS AFAIK) the only thing that was changed was the raising of the height of the top rail in relation to the barrel centerline.

When I said out of spec, I was referring to their design specification. As stated above, being that there is no mil spec as with the small platform, Mfgs can do anything they want, an example would be DPMS deciding a couple of years ago to raise the height of the rail on their uppers .060". As I recall, some of the rail manufactures adjusted and offered an old style and new style DPMS rail, but some chose not to. I don't know what JD's designed upper rail height is, but it ought to match the height of some Mfgs rail, if not I would say it's "out of spec" . I would think that if it is they ought tp replace it with one that will match the height of a standard (new style?) DPMS compatible rail.

You have a new model. It might be out of spec. (don't know what tolerance they allow), but as long a s you don't try to mount an optic that bridges the upper and the top rail of the handguard (never a good idea), .020" shouldn't cause you any trouble.

Not looking to add confusion here, but I've heard two schools of though on the aluminum /steel issue. Aluminum expands at a different rate than steel, I prefer to use a steel, but many are using the aluminum JP's so they must work OK. Another debate is the clamp vs setscrew. I have read that you ideally don't want to make a localized point of pressure on your barrel if you can help it, either with tightening the two set screws too much or tightening the clamp too much. I like to dimple the barrel slightly, make sure I have a snug GB barrel fit and just tighten the set screws enough to snug (with locktite). I don't know if it really makes that much difference. I also don't know if the aluminum blocks are susceptible to erosion because I have used the steels exclusivly.

I've got a PRI adjustable gas block mounted to a 300blk barrel (.750" I think), and it's under a 12.5" Apex FF tube. Mine is the old style tube made when they had a smaller tube for small platform than large. I can't guarantee it but it looks to me like there is enough room under mine (which is smaller than the present ones) to mount a low pro PRI adjustable .936". I don't know if you expect to be needing to adjust the GB on a regular basis, but on mine, since the Apex tube mounts to tha barrel nut mount with 4 radially located bolts, I took the tube off while I adjusted the gas impulse to cycle my lightened bcg, and once it was set I bolted the tube on. If you expect to be adjusting it regularly, and don't want to remove the tube, You will probably need to make access port on the side of the FF tube.

I wasn't trying to attack LE in my last post, although it would appear that those LAPD LE that have shot up two cars and wounded two people in the pursuit of this guy were overreacting. It would seem to me that the only justification for shooting these two vehicles up as they did, would be if you KNEW that this guy was definitley the one in the car, or if the people in the cars had initiated gun fire. I was actually trying to point out that banning private individuals from gun ownership will not prevent things like this from happening, and since they are not trying to ban LE from carrying guns, due to the actions of certain mentally ill individuals, then they shouldn't use it as an excuse to prevent law abiding private citizens from being armed as well.

I'm not suggesting that it is appropriate to "shoot it out" with police, or even advisable. One armed individual in a car doesn't stand much of a chance of coming out on top against a group of armed police wearing body armor. I was trying to make the point that if the Gov,(local/state/federal) employs people that are so irresponsible as to shoot up cars with unarmed womed in them, in the supposed pursuit of a criminal that they supposedly want to apprehend and not assasinate, then the guns in their hands are as much or more of a hazard to innocent people as those that the Gov is trying to take away from private citizens. Did you see the picture of the back of the car that the two women were driving? It looked like something from Bonney and Clyde. Although I don't advocate that anyone return fire with police lawfully trying to arrest them, I think that if LE are operating with such total disregard for those that they are trying to protect than we really are on our own, and it's like the wild west, and if innocent people are hurt or killed it will just be considered collateral damage. I'd have to say that if I'm minding my own business, and ANYONE no matter who, starts shooting at me, I should have the ability to shoot back. just because it's a mistake doesn't make it OK for them to act with such wanten disregard for the lives of people that are on the street. I think that to expect them to make sure that they are shooting at the right people before they open fire is not too much to expect, and this didn't happen just once but twice that I'm aware of in this perticular manhunt.

I thought that as a favor to Boots Obermeyer krieger were not offering the 5R rifling on the AR .308 and M1A barrels. Has that changed?

If accuracy was my priority I'd also opt for the GAP gun, but, considering the present demand, maybe you need to also consider which of the companies you've named will be able to deliver a gun in a reasonable time frame.

I'm sure that I have read only a fraction of the information that has been printed/posted, about this, but I'm wondering how LAPD can get away with shooting up unarmed people that don't even fit this guys description and are driving different model vehicles than he is supposed to be. Either they are trying to silence him before he can be aprehended, or they must be some of the most inept LE in the country. And these are the people that the present administration feels are competent to carry guns while private citizens are not considered responsible enough, and they want us disarmed. Based on the LAPD shooting unarmed people going about their business, maybe we need guns to protect ourselves from them. It seems to me that this whole situation is a good example of why we need to be armed, not why we shouldn't be. And that doesn't even begin to address the implications of them using the drones on American soil. Looks like things are proceeding very quickly towards a future that many are unwilling to believe could ever happen in America.

Thanks, Rsquared, I owe you one. Let me know if there's ever anything I can do to return the favor.

Rsquared, Your generosity is much appreciated. I will PM you shortly. And as mentioned by others, This exchange reminds me once again,how fortunate I am to be a part of this forum and the great people that make up it's membership. With the current gun ban situation, it seems as though the gun rights issue has really forced people to pick a side, and the more people that I meet that are on the other side, the more proud I feel to be included in the Pro gun group. I have found that gun people are a much better group and I'm glad to be counted among them. These days when someone tells me that they support the gun ban, I immediately question their competence, judgement and ulterior motives.

Thanks Drew. If Armalite comes through for me, I'll post that I'm no longer in need.

I'm in need of a firing pin spring for an AR 10. I have just finished a build and had to take the one out of my MA TEN to complete it, so I now have two .308 AR's with AR 10 BCG's but only one FP spring. I've got an order in with Armalite, but there's no telling when they will be available. If anyone has a spare that they would be willing to part with, I'd be happy to pay your price and replace it whenever Armalite comes through.

I think that the rational of the heavy firepower is to be able to quell riots, that and the fact that the taxpayer is picking up the tab. With the current situation regarding a possible national gun ban, I bet the departments that have the heavy weaponry are glad they do right now. The question really is, will LE choose to execute the citizens that refuse to be disarmed?

Looks like the anti gun people don't really like the idea of people knowing that they might be unarmed, or being without someone with a gun to protect them and in fact they see nothing wrong with armed private security, wonder who's paying for their armed security? http://www.pagunblog.com/2013/01/15/the-silence-of-the-anti-gunners/

I don't know if my advice will reflect the current situation with regards to parts availability, but I recently found an Armalite bolt carrier to complete one of my builds, and when I was searching for it, I noticed that they were much harder to locate than barrels. So, since it's recommended that you match your bolt type (Armalite or DPMS) to your barrel extension, it might be a good idea if you were to wait until you've got your BCG, or at least the bolt, before ordering your barrel, that way you will be able to be sure to order one that matches the BCG you finally end up with. BTW, I've used both types and they each have worked equaly well in the MA Ten receivers for me.

That IS very impressive. i made an effort to build a lightweight .308 AR, and mine came in at around 8 lbs according to my bathroom scale. My gun was built with a lightweight Kaiser receiver set, along with a CTR carbine stock similar to your's. I put an 18" carbine fiber wrapped barrel on mine as well. The two things other than the possibility that my barrel outweighs yours, that I'm assuming are heavier on mine, are the 13" Larue railed handguard, and the heavier DPMS BCG. Do you think that your CF free float tube and JP carrier could account for over a pound in weight savings as compared to the parts I've used? Also who's pencil barrel did you use?

I probably should habve done this before ordering, but, i just ordered one of the X-treme shooting products AR triggers to try out in my .308 bench gun build. I was wondering if any members have tried this trigger, and if so what was your experience? I'd also be interested to hear if anyone has tried their bolt gun triggers? They're pretty pricey but I might have a project coming up that could benefit from one.

That Youngs .308 carrier sure is a good looking part, just like their 5.56 carriers that i run. I waited for over six month for one of them, kept being told that they'd be avaliable in another month, before I finally gave up and picked up an Armalite recently,in order to finish my current build. I wonder if they'll ever be a stock item from them.

Maybe those more knowledgable could educate me on this. I'm trying to figure out how much punishment the carrier actually takes. When the gun is fired, I thought that the gas impulse on the carrier key is what causes the BCG to begin it's rearward travel. I thought that when the gas pressure goes from the end of the gas tube into the gas key, it exerts pressure which enters the cavity in the carrier behind the bolt. I thought that this pressure trys to seperate the bolt and carrier, and that is what drives the carrier rearward, until the holes on the side of the carrier are exposed, and then the pressure bleeds off, but since the carrier is traveling rearward (against the resistance of the buffer spring) it eventually acts on the cam and unlocks the bolt. The reason I ask this, is because I'm trying to get an idea of just how tough the carrier needs to be? I know the bolt needs to be tough so that the lugs can handle the load of the cartridge ignition without sheering, but I'm thinking that since there is nothing holding the end of the gas tube into the gas key, the gas tube would rupture long before the bolt carrier would fail. Any opinions on this? I'm not sure why the carrier would need to be as strong as the bolt needs to be. So maybe this IS a part that could be manufactured by the average shop, as long as all of the dimensions were maintained?

Ive used the Eotechs and some of the mini Holographic sights (Trijicon STS, and Nikko Sturling Diamond Pro t, and C more slide ride ) I love them, and find that if you are realistic about your application, you don't need to spend $500 for them. I think that if your really going to be using one in combat, than the extra money should not be a consideration, but for the rest of us, all you need is a dot that holds it's zero, and can stand up to the recoil of the intended host weapon. All of mine have been trouble free, but I would imagine that the ACOG, ot Trijicon T1 would be more durable in combat. Also, all of mine require that you turn them on, which may not be ideal if you want to be able to pick up the weapon and shoot in an emergency. I believe that the RMR has fiberoptic reticle, so might be better if that is your application. I'm planning to pick up one of the Cmore RTS sights to try out soon.

I believe that your idea makes a lot of sense. You say that you are good at research. With the the internet, and venue's such as this forum, it should be easy to get the word out. The thing we need is the verifyable information on who the people are that we need to boycott. i think we already know one newspaper that people in Westchester should boycott, The White Plains Journal Times, along with any company that is buying advertising space in the paper. And as you point out, it's not enough that you stop buying their products and services, you have to tell them why you will no longer be spending your money with them, along with making sure to tell them that you are telling all of your friends and family to do the same. The anti gun crowd seems to want to try to attach some blame for Newtown and the actions of other mentally ill individuals on responsible gun owners. They think that if they shame us enough we will keep quiet while they take away our rights. We need to stand up to them and use the financial power of 2nd amendment supporting citizens of this country to make them realize what will happen. Maybe it's time for all of these companies that are so damn worried about being politically correct, to take a stand on this matter, one way or the other. Then, at least we'll be able to know who our enemies (in this country) are.

I borrowed this from another forum, and although it's been covered before, I think the writer has handled the topic well, and it would be worth the trouble for all gun owners to read this, and start seriously preparing for the eventual consequences we can expect, if the proposed gun legislation is passed. http://www.zerohedge.com/news/2012-12-28/guest-post-feinsteins-gun-control-bill-will-trigger-next-american-revolution