98Z5V

The opposite of both those statements is true, as well. You decrease dwell time - go to a shorter barrel, same gas system length, same journal size - then you need to increase gas port diameter. You go UP in caliber, all things being equal, then you need to go up in gas port diameter, to a certain extent. Caliber plays a definite role in this, because of barrel wall thickness - but caliber isn't the first thing you need to look at to figure out a proper gas port diameter. Based in this information, my 18" rifle gas 7mm-08 barrel with a 0.750" journal will need a gas port that's right around 0.090", in order to function with a recoil system that's designed for large frame ARs, and in order to balance the two systems. We'll see where it's at when the barrel gets here. I'm pretty sure I'll be drilling it up.

I love this thread already...

A 15" gas tube is rifle length gas tube. 8" from the end of the barrel makes sense, for a 22" barrel. If it was a 20" rifle gas barrel, that gas port needs to be 6.875" from the very end of the barrel. Or it's made wrong.

18" rifle gas .308 Win barrels with 0.750" journals need right at 0.095" gas ports. 20" rifle gas .308 Win barrels with 0.750" journals need around 0.090" gas ports. It's a range of about 0.005" of a window that will get you running right. I list the number in the middle. A 22" rifle gas .308 Win barrel with a 0.750" journal would need a gas port about 0.085". You increase dwell time, then you need to decrease gas port diameter. You go down in caliber, you go down in gas port size. My 20" rifle gas .260 Rem barrel is 2 caliber sizes away from .308 Win, has a 0.750" journal, and runs a gas port diameter of 0.080" You're pretty far away from .308". About 5 caliber sizes away. With that barrel combination, I'm seriously estimating that you'd need a gas port around 0.060" for that barrel config and caliber. There's no shrinking the gas port diameter, so it's time to buy a good adjustable gas block. You're gonna need it. Recoil system definitely needs addresses, and corrected, in order to run the gas port diameters that I suggest. Recoil system has to be straight first - but both systems also need to be balanced. Now, here's what I think is going on with your gun... That thing is a speed demon. That BCG is hauling some serious ass, because it's WAY overgassed, AND it's under-recoiled. I'll bet that's the H1 buffer in there, at 3.8oz, and that doesn't belong in a large frame at all. You need an H3 buffer (5.4oz, or as close to it as you can get) to control the ass and mass of the large-frames, when under recoil. So, you're way overgassed, it's under-recoiled, the BCG is just screamin' inside that upper. It's going so fast that the bolt catch can't catch it and lock it back, and it's going so fast that it's not stripping the next round - the Mag spring can't get it up there in position fast enough for the bolt face to grab it. Best buffer to get easily is the KAK Shorty heavy buffer, which comes in at 5.3oz. It's easy to get. Best overall buffer to get is one from Clint at HeavyBuffers.com. The one you'd want is the first one on this page linked below, comes in at 5.5oz - it's the CAR-10 Buffer: https://heavybuffers.com/ar10carbine.html That's my honest assessment, and opinion...

I'm working on a number for the gas port diameter that should work. What's the length and weight of that buffer? It has to be 2.500" long, and I'm betting it weighs 3.8oz. Need confirmation. You're going to need a Sprinco Orange spring for the proper recoil spring on large-frames running the 7.000" extension.

I have a video, brother... It is alive and well... Testing loads. All loads need to go up. Great data today, and we'll use it all. Vid soon. Until then...

No worries = that's literally why we're here. With the info, we can get this gun running.

Good. What's the internal depth of your receiver extension? Not the overall length, the internal depth. It's either gonna be 7.000" internal or it's gonna be 7 5/8" internal, or it's manufactured wrong. 6 15/16" is a very acceptable answer, if that's the case. Next, after that answer, do you have any AR15 adjustable carbine buffers that you can configure to 5.4oz (H3 weight), and either an Armalite EA-1095 spring or a Sprinco Red spring? This will make a functional recoil system, IF they're installed inside a receiver extension that's 7 5/8" internal depth. You install a recoil system identical to what I described, and function test your gun and tell me what's happening - and I can tell you if your gas system is gonna need work. Of course, I'll need all the specs on your barrel, in order to do that. I need to know that your gas block journal diameter is, what your gas PORT diameter is, what gas system you're running (it's either midlength, rifle, or some weird rifle+2" system). I need to see a pic of how far your gas tube protrudes into your upper receiver, with your BCG out, to verify how far it reaches into the cam pin cutout in the upper receiver... ^^^ You get that information into this thread, and I can make your gun run. I guarantee you that. This is the level of detail we're talking about. This is why we have the Waterboarding thread in the first place - we have to sometimes waterboard people to get the pertinent details out of them... It can get frustrating, from our side...

The only company that I know of that ever pulled off a functional 22-250 complete gun, right from the factory, was Olympic Arms.

You either have a gas system issue, or a recoil system issue, or a feeding issue (and that's magazines). This is gonna come down to one of those 3 things, or a combination. Gonna need those technical gun specs that have been requested of you, per the details in the waterboarding thread that was linked above. Read that thread first, so you can see the amount of detail necessary to diagnose a gas gun functional issue over the internet.

Want GoPro?...

Ohio Ordnance Works, brother! I've been watching that thing for years...

Hop a flight, brother. Me and @JBMatt are heading out around 0800 local time. I think we're ready...

Someone is shooting some 500BLK in the morning. Well, I'll bet that's the case, anyway. I'm just sayin'...

Thank you, Rob... @Robocop1051 Someone guess what's going on here...

You bastards! It's Christmas, for God's sake!

Perfect.

That's badass, Rene! Thanks for finding and posting that one! That's tough to pull off, back to back to back like that. Fuckin' AWESOME! That kid is gonna fast track, for sure. Pulling that off as a PFC means immediate promotion to Specialist. As soon as he's eligible for the Sergeant promotion board (in the Secondary Zone), he hits the board, and is automatically promoted a couple months later, to Sergeant, regardless of posted cutoff points. The tab gives him that.

Merry Christmas, fellas. Honored to know you, I mean that. Seriously.

Brother! You got the book?! I've read that thing 5 times, love it.

I have a Mk18 RIS II Rail on a 14.5" pinned gun. That's my HD gun, my go-to carbine, above all other guns. It's the ARFCOM first series receiver, that was the licensed reproduction of the MagPul receiver, and I got in right away, and got a low serial number. ARFCOM ended up having 3 versions, I think I recall, and they kept changing things for the worse. The first series was tits. I'll pick up one of the RIS III rails, in the 12-ish inch version, and build another HD gun. If I can find the DD 14.5" CHF barrel, I'll get that, too. Quality rail, all the way. The new gun going around this rail will probably be on Noveske receivers - but I have a hard time ignoring the pure sexiness of Aero's M4E1 receivers...

Many are familiar with the RIS II Rail system. Built to run a free float rail on a M4A1 Carbine, full quad rail, and still be able to mount the M203 granade laucher - and keep the rail. It became standard equipment in SOCOM in 2005. They just released the RIS III Rail, and yes, I will be getting one. Here's one writeup on the release, from Guns & Ammo magazine: https://www.gunsandammo.com/editorial/daniel-defense-riii-556-nato-rifle-ris-iii-rail/467335/?utm_source=GATdaily&utm_medium=email&utm_campaign=12_22 Daniel Defense RIII 5.56 NATO Rifle & RIS III Rail Drawing on its long history of providing premium rifle components to U.S. Special Operations, Daniel Defense has updated its rifle and rail offerings with the RIII in 5.56 NATO and RIS III handguard. December 20, 2022By Tom Beckstrand There’s a fair amount of interest in the guns of the U.S. Special Operations community due to the selection process associated with them. These guns go through a ton of abuse before they are ever fielded, and then they must perform under austere circumstances for years if they expect to remain. This makes for some compelling research and development for the commercial consumer because none of us have the time or money to beat on guns like the they do. I like to keep track of what’s serving in this part of our military because it speaks highly of the companies that build the products for the market. Daniel Defense is one of those companies, and they’ve been making AR-15 forends — i.e., “rails” — for almost 20 years. The rifle issued to U.S. Army Special Operations at the turn of the century was a modified M4 carbine. It featured a quad-rail handguard that replaced the factory plastic handguards. This meant that everything touching or mounted to the handguard — light, laser, foregrip, etc. — might as well have been mounted directly to the barrel. The rifle’s accuracy suffered as a result. In 2005, the United States Army Special Operations Command (USASOC) decided to upgrade their issued M4A1 and picked the Daniel Defense RIS II. This resulted in some significant improvements. The first was that it divorced the barrel from the forend (and everything mounted to it). The barrel became “free floating,” and accuracy improved while also becoming more consistent. Next, the handguard was increased in length from 71/2 inches to 91/2 inches on carbines with a 10.3-inch barrel, and 12 inches on the 141/2-inch barreled guns. That additional real estate mattered a lot when shooting from field positions with lights and lasers mounted. Finally, the RIS II allowed the military to attach a grenade launcher to the handguard instead of the barrel. In what should be a surprise to no one, this improved accuracy significantly on those as well. Daniel Defense also saw the adoption of its barrels within SOCOM as part of a product improvement program. In 2015, USASOC decided it needed to further update its rifles with a better barrel. The M855A1 Enhanced Performance Round (EPR) had been out for a few years, and it was a higher-pressure load than anything previously fielded. The additional pressure was hard on the barrel’s rifling and SOCOM saw barrel life drop precipitously. They decided to adopt Daniel Defense’s hammer-forged and chrome-lined 141/2-inch barrel with mid-length gas system. (I remember being shocked that USASOC took AR-15 barrels seriously enough to come up with the right answer. Later, I came to find out that a couple of friends of mine were responsible for that project, so I shouldn’t have been surprised.) Hammer-forging the barrel work-hardens the bore and makes it more resistant to wear than cut- or button-rifled barrels. The military previously used button-rifled barrels, so the new hammer-forging process gave them a measurable increase in barrel life. Lengthening the gas system allowed the bolt to stay closed longer and let chamber pressure drop before unlocking the bolt to extract the fired case. The M855A1 quickly earned a reputation for shearing bolt lugs when the bolt twisted to unlock for having a higher chamber pressure. Lengthening the gas system provided some much-needed relief. USASOC liked Daniel Defense’s barrel so much, they continue to use it today. All of that tribal knowledge has made its way to the newest rifle from Daniel Defense: The RIII. This rifle features a forend that attaches to the rifle in the exact same manner as the RIS II, but it replaces the long sections of Picatinny rail on the RIS II with smooth, hand-friendly sections of M-Lok. M-Lok is SOCOM’s attachment method, so it’s no surprise to see it on the RIS III ($476).

^^^ That's what I was gonna recommend.

Man, they're like mountain goats. With no shoes. Unreal.