98Z5V

All gauges are good - to what the manufacturer specs, and they make them in accordance with cartridge specs. But there are tolerances, even in the case dimension drawings, on every cartridge. It all comes down to what gauges your barrel manufacturer uses, when setting up their chambers for Go and No-Go, and how tight they set their headspace for those gauges. Some gauges will give you a No-Go on a Go gauge, just based on that.

I feel some deceit and treachery on my horizon...

Rule #1 with adjustable gas blocks. You run adjustable gas blocks WIDE OPEN, like you'd savage a 2-stroke MX bike on a motocross track. You ALWAYS start an adjustable gas block WIDE OPEN. If you don't, you're wasting ammo, and wasting time. If it's not wide open, you'll never, ever know if your gas port is large enough - which your's isn't. Rule #2. Dwell time. Distance between the gas port and the end of the barrel. Exactly why I asked you to specifically define your "XL Gas System" that you got from JP. Rule #3. Gas block journal diameter. You never stated it, and I'm not looking it up on JP's website, for your barrel. What's the journal diameter? You answered alot, with the details you provided - but there's alot more that you left out. I'll fix your .260 - I have 2 that run like Swiss watches. Until I get these details, I'm wearing a blindfold, and throwing darts at the dartboard...

Define that gas system length, exactly. How long is your gas sytem - it's not rifle-length gas - and how long is that gas tube, end to end, exactly... Details. Not names. Numbers, matter. That gas port size is fucked for a .260 Rem, with your barrel dimensions that have been stated. Thanks, JP, for sending us another customer. Let's see what JP says about this - so make SURE you post what they reply to you... You're dealing with Race Gun Parts - and not trying to make a Race Gun. That's the first problem...

There is - in my head. I've written about it as much as I can, every single time I can, and I spill details as often as I can - on why gas ports work. And when recoil systems must be matched. And why both systems MUST be balanced, in order to reliable function your rifle. Gas systems and recoil systems are the heart of your reliability. I've delved into this as much as I can here, on why what works, WHAT works... Different journal diameters just came up the other day, and I got into that. And why. It really just sucks to keep going over it, time and time again, it really does. The info is already all here. Hate to be a dick about it, but the info is already here. I've even made posts on how to calculate it. With diagrams, because some of the guys here need the crayon-method to comprehend shiit. I'm talking about the old-timers, too - not newbies.

I kinda figured you wouldn't see that for at LEAST 2 days...

That certainly didn't take long... The bait was set!...

I'd REALLY LOVE to explode a swimming beaver head with that fatass .358 round, man, like you can't believe. Hell, I'd like to crush one with the 45-70... I went with Athlon for the optic, new, not raided from another gun. I've been down that road, raiding optics and such. It catches up with you... I think it was about 2 years ago, that I had to buy 2 new scopes, 3 new mounts, and "shuffle back" all the damage I'd done by moving a total of 5 scopes and mounts around on different shiit. Never again. The ONLY mil option that Athlon has for a short scope is the Talos BTR in a 1~4 range. That's alright, because as far as this 250gr round will travel, it might be easier throwing bricks at something instead. Everything in the 1~6 and 1~8 range that they offer is in MOA. ALL the transexuals love them some MOA, but I just can't do it. Mils or death, for me. I need to talk to Drake at Athlon, and get this fixed. I think he'll get a phonecall after the shoot, just over mils, and short scopes... He was here in town a couple weeks ago, AT THE DAMN GUNSHOP, whilst I was working my day job. GunPusher John, dick that he is, calls me on speakerphone, and him and Drake are double-fucking me on the phone, laughing because I can't get there before Drake has to head out of town. The fuckers. He's lucky I couldn't leave work right then... On the 12.5" 6 ARC gun, I did the Athlon 20 MOA mount as a placeholder, until my 8-month backordered LaRue mount came in - and I really like the Athlon mount. So I left it on that gun. At any rate, the Athlon mounts are legit, and I did a 0 MOA Athlon mount with this scope for this gun - and it's gonna work. So, there's the details on the scope and mount that I went with - without falling down that rabbit-hole of raiding more scopes. This was, we all get to shoot the 16" .308 Win Carbine against the 16" .338 Fed Carbine against the 16" .358 Win Carbine - at the same time, without raiding optics. Heads-up. All 3. Here's the Athlon scope I went with: https://athlonoptics.com/product/rifle-scopes-talos-btr-1-4x24-ahsr14-sfp-ir-mil/

Why?

Probably. And the Nitride is way better than having the internals chrome-lined. FWIW.

So, no research yet, just looking for what to get, where? Ever built an AR15 variant before? Ever put together any AR from parts? Starting with a large-frame AR is a hard way to go, as far as that goes. Starting with a small-frame AR would make life easier on you, as you'd get the machanics of putting it together down, without the headaches of dealing with the differences in the Large-Frame market... But, that's just my $0.02 on it.

They do, when you buy at the same time. If you order online, list that request in the comments line, in your order... "Please check headspace on the bolt and barrel before shipping..."

Done. Ready to shoot.

^^^ Correct.

Smaller firing pin tip, and corresponding smaller hole in the bolt face for it.

When there's a chance, can a Mod/Admin move this to the Build Section?

@AzRon Should be anything listed as AR15 Carbine receiver extension, from a known good manufacturer or vendor. If you want to make sure and not worry, get a BCM or VLTOR, or a company along those same lines.

@AzRon, that looks like a legit 6 13/16" in that one pic, right to the edge of the extension itself. That extension is bad. The REAL SPEC is the Armalite AR-15 spec, which is 6 15/16" internal. The aftermarket went 7.000" internal, and there has never been a problem running 7" of depth, 16" longer than the real spec... This one is short, and that's causing your problems, directly.

Hated to hear your update, brother - bad! There's something off with that one, for sure.

We don't know yet, brother, because you've never given us the internal depth of the one that's on your gun right now... Post up the internal depth of what's on your gun right now, first...

I really, really like this statement...

WHOOOO!!! You're gonna be busy - I just saw your other thread, and gave out information in that one. You need to balance both threads now, with the info that will be poring in... Should have kept everything in one thread.

I've stated for a very long time here that the barrel and trigger are the heart of your accuracy. The gas system and recoil system are the heart of your reliability. I have that information in a very, very long thread that I've made, describing all these parts, and how they interact - and either work together or not. Research and the correct parts selection - as well as questions here before selling all those great parts off - would have prevented this. We could have fixed this gun, easily, and made it run like a champ. No, it's not. It's just incorrect parts selection, that didn't work together, and the gun didn't work. Because of the incorrect parts used. Again, we could have prevented this, had the details been given beforehand. That didn't happen, though. You never balanced the recoil system to the gas system - and the gun didn't run. Read this - it's been here since 2018, when I got tired of seeing information such as yours, and made this thread, specifically to address mis-information on this weapons platform:

This is incorrect info from Aero. I have several rifle-gas guns that use only Carbine Recoil Systems. Something is fucked up with your gun if your parts aren't working. H2 buffer is your primary problem, right away. It's too light. You need H3 at a minimum (5.4oz). Feel free to tell an Aero Rep that they can hop on here and debate this with me, if they wish. I'll fix it, and the bad information going out. I love Aero, always will. This isn't good info, though, coming out of them. It's inaccurate info.