98Z5V

That doesn't make it right. THink what you want, that's too damn small.

PIcs of what I'm talking about... First, gas tube is too short. Don't screw yourself on the available gas impulse, take advantage of all that's available, by design (by Eugene Stoner's design). Gas tube should come to the very center of the cam pin cutout in order to do that. You can't do that when the tube is too short. Second, the gas port in the barrel let 0.073" pass, but 0.076" did not. That gas port needs opened up, it's too small. It needs to be 0.080" minimum, and might go up from there. Third, the height-over-bore on a .308 AR is higher than on the AR15 guns. The cartridge is larger, the upper receiver is larger, etc. It's a fact. If you were to measure from the center of the bore to the center of the gas tube diameter, the 308AR is a bigger beast than the 15. This is an AR15 midlength gastube. The AR-10 Carbine gas tube has larger bends, and it comes up higher, to account for that increased height-over-bore. When you use an AR15 midlength gastube on these things, you have to "bend" the gas tube to make it work (That info is coming up). This is a picture of the AR15-sized OD on the barrel nut - notice that it doesn't even engage the gas tube. Usually, you have to make sure that barrel nut is precisely aligned, or you can't get your gas tube through one of those teeth. Not on this thing. You could torque that barrel nut to whatever you wanted, and you don't even have to worry about gas tube alignment, at all. Just slap it together. I'm sure the ID is larger, to fit the larger diameter barrel. I guess this makes it easier to assemble, though, and you can just used an AR15 Armorer's Wrench on it. There's a reason there are .308AR Armorer's wrenches, though - to handle the larger barrel nut. My preference for one of those is PRI. They make the beefiest ones. Now, sine an AR15 midlength gas tube was used, and it doesn't have the appropriate bends for the larger height-over-bore of a large-frame AR, you have to "tweak it upwards" out of the gas block in order to get it into the upper receiver, and that higher hole in the upper receiver... Based on that, there's alot og carbon buildup - which is gas leakage at the gas block exit... Pic with flash: Better pic of the carbon buildup, no flash (but a shiitty, unfocused pic)...

Found the thread with our original gas port data: Found it by looking for this chart, that I knew I'd seen here. .308 min and max gas port sizes, by barrel length, from one specific reputable manufacturer:

Okay, basic PSA upper, no BCG no charging handle, it damn sure goes into a DPMS lower alot easier, but there's still that interference with the bolt catch paddle. You have to slightly push in on the bottom of the bolt catch (like you were trying to engage it, and lock a bolt to the rear). So, you have to hit the catch a little, and rotate that paddle out of the way of where it's hitting in that cutout on the upper. If you don't, and you were to slam the upper and lower together, it would move that paddle on it's own, anyway. That make any sense, with words only?... So, here's the deal - when you pivot that bolt catch a little, you're raising the internal part, that would grab the bolt face - its not flat, like it should be, resting on that upper flat surface of the lower receiver. It's not "at rest" and flat, it's raised. @Gopher,you ever notice that on your PSA lower, brother? Troubles closing and pinning the receivers unless you kicked that thing outta the way a little? If it happened to you, then I'll relieve that area in the upper receiver a little, so it doesn't happen anymore. I don't want to do that, if it's only an issue I'm having, and it doesn't happen to you. Test fit with BCG and CH coming up. UPDATE: Yeah, BCG and CH in the PSA upper, pinned to the DPMS lower. It pins, just fine - gotta move the bolt catch a smidge. Won't function. Will not. That bolt catch is raised a little, to fit the upper and lower together, and the BCG drags on it, and stops all rearward progress in less than one inch of BCG travel. It won't cycle. So, a PSA Gen 2 upper will not work on an Aero Precision M5 lower receiver, and it will not work on a DPMS LR-308 lower receiver. It won't even pin down on the AP M5. The only way to make it work on a DPMS LR-308 lower is to either trim down the paddle on your bolt catch, or relieve that shallow area cutout in the PSA upper. No other way. So. One of two things is happening at PSA. They're using their own proprietary 308 bolt catch, that's shorter than a DPMS LR bolt catch, and shorter than the AP M5 bolt catch... OR... Their Gen 2 lower is different, and it "sits" these standard 308 bolt catches lower in the frame. That would be a big machining difference from those other two samples.

Jameson likes me, too! Tends to make me slow the next day, though. VERY slow...

Baby steps, brother, baby steps... I need to find a gun I've got that this upper is gonna run on!... I'm digging that DPMS out now... Armalite AR-10 Carbine gas tubes are out-of-stock everywhere, and I'm on several email-notification lists right now for them. I've got one here, so that won't slow us down. Gas port size will come up. FSB will get chopped, and re-pinned to the barrel. This thing is gonna run this weekend, even if I have to take two guns completely apart and mount your barrel, charging handle and BCG into an Aero setup to run it. Hopefully, the DPMS lower and PSA upper play well together...

Gas port data: PSA Stainless .308 barrel, "midlength" gas system. 0.073" fits, 0.076" does not fit. I'm thinking this gas port is too small, and needs to be around 0.080". That would explain the weaker recoil system that it is shipped with - it's underpowered. A PSA PA-10 Gen 2 upper receiver will not work on an Aero Precision M5 lower. It won't. You can't close the receivers and pin the rear takedown pin, because the relief cut in the upper (for the bolt catch paddle) hits the bolt catch paddle. It's almost like the relief cut in the upper receiver isn't cut high enough. If you slightly depress the bolt catch, the upper will close on the lower, but you have to tap the takedown pin in there with a small poly hammer. You can only do this if the charging handle is not in the upper. If the charging handle is in the upper, the charging handle makes contact with the Aero M5 lower receiver, and the halves will not close to a point where you can pin them together. If you forced this to happen, you'd bind the charging handle in place, and never be able to hand cycle the weapon via the charging handle. I used the standard PSA charging handle, and a BCM Gunfighter charging handle, same results. I can't physically try the PSA upper on a Matrix lower - the Matrix I have is the Armalite-type angled cut, so the two will never physically fit together. I forgot about that when I said I was gonna try it. Moving on to the genuine DPMS LR-308 lower now...

PSA 18" Stainless .308 barrel, "midlength" gas system. 0.073" fits, 0.076" does not fit. This gas port is too small.

That's what you need to fix what you currently have.

Phoenix, last night. Just finishing his training, two others were shot. Shiitbag in custody. http://www.foxnews.com/us/2018/07/26/arizona-trooper-in-training-killed-trooper-wounded-in-shooting.html

PIcked up Gopher's upper today, and I've been in it all this afternoon. It won't pin to an Aero Precision M5 lower. There are some things I'm seeing right now that are slightly different from the AP M5 stuff, and I'll get all into that. This is gonna be an interesting weekend. I will pull out the DPMS LR-308 lower and the Matrix Aerospace lower, and the other AP lowers, and be doing some serious upper/lower fitment exercises and comparisons with those other uppers...

When you look at emotions, there are only TWO Primary Emotions. Only two. They are the reaction to everything that startles you, one, or the other. People say "Fight or Flight," but that's not it. The two Primary Emotions are Fear and Anger. When startled, one or the other will come to the surface. That's gonna be hard to prove in court, right there. That it was one over the other.

Gonna be good!

I'm still here for you, no matter what. No matter how grumpy, interrupted, whatever. I'm like your mouthy first son, that you want to smack the shiit out of...

You could break a fucking anvil in a sand pit, man. I'm just sayin'...

She's pretty bitchin'... This is the stall point.

Just set that wrench up at 90 degrees to the "crow's foot" - which is your armorers wrench, and do what it needs. You'll be fine.

You're grumpy right now - if you read what I wrote, you'd probably agree with me...

It'l be dirt-colored, for sure, and sexy as hell. You might wanna put it in the house, and not beat it up in the truck...

Not yet, but that's on the way. I have another couple of mine that I need to paint, and it'l be a batch-job on them all. I did touch it today, though - I licked it...

Doesn't make sense Mack. Not at all. We already have signs that identify Handicapped parking, and people can't fucking follow that... More signs won't help - these stupid fuckers can't follow the signs that are already out there... ...and the lack of attention to detail on the Handicapped sign is why we're here in the first place. People are either SO stupid that they can't read, AND don't know what picture-signs mean, or they don't fucking care, and do what they want... Another sign just means more people will get shot - because they're too stupid, or don't care. Darwin is outta work these days, and doesn't take care of HIS business, so I don't mind if the "too stupid" and "don't care" people get removed. Darwin ain't doin' it, these days... Someone has to pick up Darwin's slack... It's just like all the other laws we have... they're stupid, or they don't care about those laws...

Yeah, I said that... Set it up how you want, calculate what you want. Do what you want. You're over-thinking it.

People don't have these issues with standard parts, special castle nuts, and a receiver endplate that is complicated like yours. They just don't. They just tighten it down, stake the damn thing, and never have to worry about anything else, ever in the life of their recoil system, and it never loosens up... So... Yes, you complicated shiit with complicated shiit, and you're worried that it might come loose later one, and you want to make sure it's exactly on spec due to that... I hope that makes sense. So, you're looking at about 7.25" of extension, minus diameter (or thickness). You're about 1" off of that, so use 6.25" for your calculations. Depends on your torque wrench, really, and how far the pivot head is away from the center of the ratchet... but the real truth is that it won't matter. That would matter, if it was straight on - torque wrench lined up with your extension, in this case either 7.25" or 6.25", witchever method you believe in. When you torque it at 90 degrees - it negates that extension, every time. That's why I linked the information that I did. Beyond that first post in what I linked, further below, like 4th reply down, is the information that you really need. The rest of the answers for calculating the increased length, 7.25, or 6.25, are in the article I linked. Short answer - set it up on a 90 degree angle, like should be done when working with a crow's foot, and it doesn't really matter. I think I said that right away - set it up at a 90 degree angle... Good luck.

^^^ This is why I don't complicate shiit with complicated shiit, FWIW...

Yes, but not enough to make a difference on this part. The torque wrench being further away from the attachment point on the armorer's wrench will increase the torque. There's a formula for figuring that out: https://www.finishing.com/118/94_crows_foot_torque.shtml Show me a picture of a tape measure beside your armorer's wrench, and I'll tell you exactly what it will be, and spell out the formula for that armorer's wrench.