Jgun

First off, I have no connection whatsoever to this item or the seller. I am only posting it here so that it doesn't get moved here if I were to post it in the Larue section. I came across this the other day and was impressed by the claimed weight of 8.5 lbs. I think that Larue makes an excellent product and if I were in the market for a factory built gun I might be giving it some thought. www.gunbroker.com/Auction/ViewItem.aspx?Item=244141729

Robocop, I recently installed one in my 300BLK build. I know that's not 7.62X51, and is built on the AR 15 platform, but since it's a multi piece 2 pin trigger set and not a one piece drop in module, I would expect it to work for you. I, also am a fan of flat triggers for rifles as well as pistols. when I spoke to Geiselle, they told me that they use the same hammer spring in all their triggers to assure reliable ignition. Although there is no military 300 ammo to test it with, I'd be willing to bet that it would function fine in your application, even if you use military ammo. My impression of the trigger is that it's a good product with a real short reset and clean break. This trigger is preset and non adjustable at 3.5lbs. I found that compared to my SR gold and the Jard 2lb in my .308 guns, the Geiselle has a noticably heavier pull. That is also the concensus amoung my friends that have tried it. If your seeking a super light trigger pull, you might want to consider one of the other Geiselle's. Of course you won't get the flat trigger with any of them. I'm not trying to disuade you on this, and after having bought and installed mine, I think I'd buy it again if I had it to do over, I just wanted to let you know that it's not a super light target trigger.

I seem to remember that the buffer damage that was pictured by the OP was much more severe than the damage I saw on the buffer in the lapping tutorial. The pics that were on the AR 15.com post are so blurry that I can't see how bad that buffer is. As I recall there was also the question of why the back of the BC didn't contact, and push the buffer off the buffer retainer when you mated the upper and lower together. I don't see how smoothing/deburring the back of the BC is going to change that. Maybe I can ask this question, The BC should "head space" far enough back in the upper so that it does in fact depress the buffer spring slightly, thereby pushing the buffer off the retainer, right? That's not an unimportant dimension, is it? If so it comes back once again to something locating the BCG further forward in that upper than is normal. Either something wrong dimensionally with the upper, the BCG (unlikely) or the barrel extension, and I guess also the buffer retainer bore could be mislocated. Although, I have not been involved with the AR's all that long and have not experienced all of those weird things that the long time AR guys I'm sure have, I have yet to see the kind of wear on any of my buffers from any of the BC's in my AR's. That includes, DPMS, Armalite and Young's BC's. If I was the owner of that IR receiver set, I'd find a way to compare my gun dimensionally to another DPMS type .308 AR that I knew to be good,and determine once and for all what (if anything) was dimensionally different on my gun from the one I knew to work, and if I found a noticeable dimensional difference that was causing the problem, I'd be on the phone with IR. As much as I don't think you should need to resort to things like that to remedy the problem, If all it took to solve it was one of those silicone bumpers I'd do it in order to have a working gun. Something else comes to mind, I recall reading that the carrier weight system required you to pull both the front and rear pins to install it and be able to open and close your AR. I'm thinking that if the problem with this one is the BC being too far forward, You might be able to add one of the CWS to add some length to the BC, solve the buffer damage problem and maybe you'd still be able to open and close that particular gun in the conventional manner, without having to pull the pivot pin?

First off don't take any of this as me being argumentative, I'm just trying to educate myself here, and maybe benefit some of the other members in the process. Since I've never actually handled one of their handguards and haven't looked down the barrel to see how much clearance they have, I'm working at a disadvantage. I have installed several gas blocks and tubes in several different AR's. I've installed .750 and .936" ones. The way I figure it, The location of the gas tube hole above bore centerline on the uppers of the AR's should be petty much the same , with the AR 15 platform being one measurement and the 7.62 AR being another, If that is not the case wouldn't you need different height gas spigots on the BC's to accommodate the difference? So presuming that the .308 AR gas tube hole is the same height above the bore center. The difference between a .750" and a .875 or .936" GB should basically be in the bore of the GB to accomodate different barrel dia's, not in the height of the gas tube hole in the GB above the bore center, Does that make sense? What I'm getting at (again) is ,there must be some GB that fits under the hand guard, and I don't think that the top surface of a .750" GB is any lower above the barrel centerline than the .875" (although the outside dia of the .875" will logically be larger than the .750") even if it was taller, it should only be taller by .063 (.125" difference divided by two). I wonder if you could just relieve the area where the gb interferes with the rail mount? You might consider calling back and asking them what gas block do they recommend WILL fit.

These are another, slightly less expensive alternative to the KAC's. Of course, these don't fold, AND they don't have the KAC name. www.dueckdefense.com/gun-sight-specs.asp

You said that they told you that their low pro gb won't work with their ff tube. If anyone would know, I guess it would be them. Couldn't they suggest a lo pro gb that would fit, even a non adjustable? I'm wondering if the reason that they told you it wouldn't work, was because there was no access to the adjustment screw. If that was the case, you could remedy the problem by making a small hole in the side of the tube. I'm thinking, that there must be some gb that should fit under the handguard, No? If so what other gas block could possibly be smaller. Maybe the issue is one of installation, or adjustment access, I'd be interested to hear how you resolve the problem, as I was thinking about trying one of their hand guards myself.

Do you mind me asking what handguard your going with? I recently built an AR 15 where I used the old style Apex hand guard, which is one of the smallest dia handguards I know of, along with the PRI adjustable lo pro gas block. Although I built a 15, and the GB I used was the .750" bore model, I can't think of any other adjustable gas block that is as small as the PRI. The one I used was identical in size to the standard lo pro GB's offered by Vltor, Troy and others, with the exception of the small adjustment screw on the right side.

Speedereamz, It would be more trouble than it would be worth, to go to the trouble of switching the 13.9 SWS rail that's presently on there for one that was only an inch shorter, and have it cost me money besides. If you know where I can get one of the 10" rails he makes for Noveske I'd be interested. Obviously, if your good for the build to begin with, switching your two piece to a different rail later on should be something that you'll certainly be capable of, but, as I mentioned in the last post, it can be a PITA to have to remove the gas block and gas tube in order to switch barrel nuts if the FF rail you happen to decide on uses a different barrel nut than the first one you mount. You might want to give it some thought. As far as I know, SWS and Daniel Defense both use proprietary barrel nuts that don't match anyone else's rails/handguards.

You might want to decide on your FF tube choice now instead of later, since some use a proprietary barrel nut that would require you to remove your gas block to install if you've already assembled the upper with a stock type barrel nut. Most of the time when I order a FF tube the instructions will give you a torque spec, or you will be instructed to hand tighten the barrel nut and then tighten the nut with the wrench until the next hole in the barrel nut lines up with the hole in the upper that the gas tube passes through. Isn't it usually around 60 fp? Now the things that come to mind for me that you would want to have to make assembling the upper easier, are an upper receiver vise block to make it easier to hold while tightening the barrel nut, and if possible some type of soft jaws to hold the barrel near the front end, to allow you to install your muzzle device on the end of the barrel without torquing against the upper/barrel connection. roll pin punches are also good for installing the gas tube pin in the gas block.

So, the right thing for IR to do, if in fact the upper is out of spec, would be to exchange it for a good one.

As is always the case when your one of the first to try somthing out , this is a bit of a gamble for me, but, as you said, this is just what I've been looking for, because I've always really liked the POF receivers but never liked the fact that if you buy a POF rifle (which I also really like) your limited as to what parts you can swap out. With the way they designed their uppers so that the handguard slides over the rail of the upper, your pretty much limited to using their setup as is. This upper will allow me to do a complete DI build using DPMS compatable parts while getting to use the POF lower receiver. As I said before I will post some pictures of the set as soon as I have it. Last time I spoke to him, Doug (the seller) told me that he had made 30 uppers in this initial run and that so far 20 of them are spoken for.

Actually, this upper is supposed to mate up to the POF lower in such a way that it will be unnecessary to use bushings as when you mate a DPMS upper to a POF lower. The upper will have .250" holes to match the .250" pivot and take down pins that POF uses. These are being made by the same people that (until recently) made POF's uppers and lowers. The seller tells me that the contour of the upper will match that of the POF lower to create a matched set. In addition, it will allow me to use whatever rail I choose and not have to use a POF rail as you would if you used a regular POF upper for a build.

I decided to try it out and have already ordered a POF lower receiver and one of these uppers. Not exactly sure just what I'm going to build with the set, but I'll post some pics once they get here.

I can't figure out how these can be importable as is, while the Gov forced Izhmash to alter the Saiga in order for it to be considered a sporting arm?

Anyone seen this? If they run, and someone starts making higher cap mags for them, I might take a serious look at them. www.akdalarms.com/mka.html

So far I have been unable to find any 300BLK ammo that actually is in stock, other than the 220 gr subsonic. I hope that the other listed loadings will eventually become available instead of just listed as out of stock or backordered.

Perceived recoil is a subjective thing. I have a MEGA .308 with a 14.5" Noveske barrel with fixed BABC muzzle brake. I find the recoil to be pretty mild, not .223 race gun mind you, but I could put 100's of rounds through it without feeling beat up afterwards. I figure your gun must be at least as heavy as mine, and the gas system/barrel length are close, so the only thing I can come up with is that I have Clint's CAR XH buffer and spring in mine. I have never tried the Endine, is there any chance the one you have is defective or malfunctioning? If recoil is truly punishing, does the carrier slam the extension at the end of it's stroke? If so you should resolve it before putting too many more rds through the gun to avoid doing any damage to it. If it's not slamming the back of the extension, you might be just experiencing the characteristics of the Endine. Maybe another member that is using one could give us their opinion.

edgecrusher, could you clarify for me, is the PRS in your pics the AR 15 or the AR 10 version?

Looks like fun, and expensive! If you don't mind me asking, What class does a truck like that chevy PU run in?

And yet another bolt gun chassis option. This one from the designers of the Magpul Massaud .308 www.kineticresearchgroup.com/products/w3c.php

Not sure just what I'm going to do with it but I decided to take a chance and ordered a POF .308 lower receiver and one of the POF compatible upper receivers that I mentioned in the last post. I'll be sure to take some pictures of the set, once I've got both pieces in my hands.

This is a topic that I would be interested to learn more about. When I was first looking at receivers to use for a .308 AR build, I was seriously considering going with one of the Iron Ridge receiver sets, but decided against it in part because their upper receiver has a 23 MOA angle built into the top rail. I had(and still have) no experience shooting at really long range, and my local range is only 200 yds. My friends told me that the built in angle was for dedicated long range guns. I have since been told that, as long as the optic has the adjustment range, you can have a 20 MOE rail and zero for 200 and just dial up for the really long stuff. Is this true? Can anyone tell me what scopes that are suitable for 1K yds have enough adjustment to be also used at 200 ?

The receiver that I was describing that had the .0025" barrel extension bore taper, was an AR-15 receiver of questionable manufacture, not an Iron Ridge, which I understand are supposed to be of extremely high quality. I just mentioned it to illustrate that a person "could " assemble one of these without seating the barrel fully, if there were any problems with the machining tolerances of the bore or the slot. All of the things that you mentioned are possibilities as well, but I'm thinking that they would require either a program or offset error. How else could you end up with a upper receiver that is physically too long while still having the pivot and takedown pin bores located correctly. All of this is academic. For me, the real question, which was asked earlier, Is why the mfg. wasn't willing to assist the owner with determining what the problem was, and resolving it. I still think that the IR receivers look really nice and would love to do a build using one. This problem just kind of discourages me from the idea. Maybe some other Iron Ridge owners could post their experiences with the brand?

Based on the Snipershide thread, it would appear that mjsemtex's problem is not unique. Others seem to have encountered it. If that is true, it would indicate that there is, or has been in the past, a problem with something being out of spec on the receiver (either upper or lower). That is just what seems most likely to me if other people (that probably are using different brand barrels) have run into the same issue. If it had happened to me I think I would have found a way to compare all of the dimensions you mentioned, on the IRA receiver set, to a rec set that I knew to be good. Also, don't know this for sure because I didn't do it, but the oversize barrel I referred to before, started into the uppers bore but then locked up. When I checked the size difference, I found that the front of the receivers bore was about .0025" bigger than the back, since the barrel just started into the front, had I attempted to press or use the barrel nut to tighten the barrel down onto the shoulder, I would have had a .002" interference fit. Not sure if the aluminum threads on the upper would have been up to the task.

The possibility that the barrel/barrel extension are not machined/assembled properly is one thing that I would be really pissed off about, it I were to find that to be the cause of the problem, but the thought that the barrel was not fully seated into the receiver bore before tightening down the barrel nut is just scary to think about, It's funny, whenever a friend shows up with a new rifle that they built, and offers to let me try it. I never give any thought to the fact that they might have done something wrong during the build and that I might be shooting an unsafe gun. Maybe I should be. I've had builds that required me to remove material from the barrel extension OD in order to get it to fully seat up to the shoulder, in the uppers bore. I've also had one barrel that the slot for the pin was so narrow I had to widen it for the barrel locating pin to fit. The pin would have probably widened the slot on it's own from the pressure of the barrel nut, but the oversize barrel would have never gone all the way to the shoulder before locking up. This is the kind of stuff that if your not competent enough to do properly, it's probably better if you leave it to a gunsmith to do for you.