98Z5V

Damn, nuke that pic.

I love how he's announcing parts arrival, and everything is plural...

I have two "long .308 Win barrels" - one is 18" and the other is 18.5". There's no need to go with a 20" for any kind of increase in accuracy or velocity, because any increase you'd see would be negligible. I do have a 20" barrel on a .260 Remington gun, only because that was the shortest I could find, without waiting for a custom barrel.

Well, that would be the key point here. "Properly set up AR buffer system" is not what he's working with.

It should be 7 5/8" internal depth, and 7 3/4" internal depth is 1/8" too much. That's 0.1250". One quarter is 0.069" thick. You need both of them - but you better verify the length of your buffer - it must be 3.250" long.

Measure the internal depth of the receiver extension, please.

I. AM. IN!!!

It's been "inserted." I'm not gonna say where, when, or what, but it's been "inserted." You get to deal with it now.

Concur - COMPLETELY! You think the biggest thing is the gas port - and I agree with that. Now I'm about to go South on you... I think the biggest thing to START with is a recoil system that will handle the pressure and power of these bigger cartridges. First. If your recoil system isn't gonna handle it, then you compromise everywhere else to make it work... 5.4oz buffer, minimum, if you're going crazy on a load, but optimum at that weight for normal charges, for the Big Frame AR, just to start with... You have to have a spring that's matched to that, too. Hell, the entire system was designed around that principle. Once you've got that - it's all about dwell time and pressure - which is all about gas system length and gas port diameter. I wish I could work in your shop, brother. Even on a vacation. We could fuk some shiit up. So many companies these days are literally "cheaping out" and building the cheapest buffers they can (means, tungsten and stainless is expensive, compared to steel and aluminum), so they "under-recoil" these things, and come up with a screwed up spring to "kinda" make it work. Directly downstream of that is making their gas ports right - or not. They often don't. People bitch, and think they need an adjustable gas block to tame down this vicious over-gassed .308 Win AR round... and here we go. It was never over-gassed. It was always "under-recoiled" because it was cheaper to build that way...

Yeah, compared to a $3,200 optic, when it does everything you stated you need - it won't hurt to try at all.

You don't need that much scope, then. You'll be fine with this one: https://www.primaryarms.com/primary-arms-4-14x44mm-riflescope-acss-hud-dmr-308-223-reticle-pa4-14xffp308 I run that scope to 845 yards on a .308 bolt gun with BORING repeatability, regularly. I run that same scope on two 5.56 guns, heavy loads, and do the same. I run the same version of that scope, in mil-dot only, on a 6.5 Grendel gun, and a 25/45 gun, and get out to the same distance.

It's just like Korea - they always know where you are, and when you're there. That's their living, man.

Do I have one? No. Have I built and tuned them? Yeah, LOTS of them. This was 10 years ago:

No shiit. I built one, then had four running around... Serious.

How damn old are you?...

I'm about 6" of dwell time on this gun, at a 0.071" gas port. This sucker will probably be going up. I should probably be in the 0.090" range on it. That means his 2" longer gas system, with around 4" dwell, needs to be over 0.100"... This is .308 info on port sizing, from a very reputable OEM manufacturer - this is all about dwell time:

We need gas port diameters from this guy, @308kiwi Gotta know that number, before anything else can take place. I'm thinking I'm not happy with my .260 gas port diameter, myself, at 0.071". I want to drill it up. I'm running a 147gr Hornady ELD-M projectile on a CCI-200 primer, reformed Hornady .308 Match brass, and 43.0 grains of a magnum powder - RL-22. It functions fine, and gets great accuracy. That's my final load on the 147s - until I start playing with RL-17... Anyway... I'm trying to make a load with the 140gr Hornady ELD-M with Accurate 2495. Same brass, same primer, 35.0 grains of it. It won't even cycle the BCG and get the brass out of the chamber - I have to pull the CH back, and fight it, to get the brass out of the chamber. That load and powder should cycle this weapon. First things first is get the 5.7oz buffer out of it, and try a 5.15oz buffer with the 140-load. If it cycles - then I need two buffers. Otherwise, that gas port is getting drilled up. The shiit we go through...

Absolutely - but only the ones that will kill me.

6.5 Grendel is an amazing cartridge.

You might have to call one of two places, to find out your information - either DPMS, or MagPul.

True - that's exactly what they are. One piece I'm not showing you in that pic, is the one I keep in the die set box. There's a special neck sizer that you run it down on, before you do any cutting. Also, that cutting tool is precisely sized (in this case, to 6.5mm) to support the neck from the inside, while you turn down the outside. Money is money, but it would be way easier to get the tool, rather than try to figure everything out to make your own jig for this job. It's only a controlled explosion, inches from your face. I'm just sayin'... Also, get the carbide one. https://kmshooting.com/neck-turning-tools.html Their instructions: https://kmshooting.com/kmshooting/media/pdf/97.pdf

Here's some background on Dickheads Sporting Goods. THose fuckers will never, ever see a penny from me. Just like CTD.

Here's what I do to make my own 300BLK brass from 5.56 NATO Lake City brass:

Now you got me on .223 brass... I do 300BLK and Sharps 25/45 from .223 brass. The 25/45 is brainless - just neck it up in the sizer die and load it and shoot it. Only take a barrel change. 300BLK is the same way (just a barrel change), but there's more work involved in converting the brass. I'll try to find the longass step-process I wrote up on it. .260 Rem. When you neck down the brass, you have the same amount of material in the neck, you just make it smaller - and it's usually thicker neck walls, because of that. Sometimes too thick to chamber. Hornady .308 Win Match Brass is the best I've found for this task, and I still need to turn the necks on about a third of them. I use a KM Precision jig to do this - they sell a really, really good kit, by caliber. Fully adjustable. It's another $100+ bucks to get into it, unless you find it somewhere cheap, but it's worth the frustration of having round not chamber on you. If you need it, you need it. On .260 Rem, you probably will, if you're converting .308 brass. I lock the converted brass down onto that shell holder, put it in the drill, and run it (slowly) down onto that cutting jig. Turns the neck diameter down to whatever I set it to.