"Ship of Theseus" beginning build

[dpete]

Welcome to the 308 AR world of no milspec.  Where you can begin a build with all the major parts from the same manufacturer thinking your good to go, only to find said manufacturer fukced up one of the parts. 

[FOGeologist]

You know what would be great? If even one word you wrote was wrong. Even a little bit.

But it's not. 

I wish some sort of sanctioning body could set the configurations up to be reliably interoperable and CORRECT. Then a measure of compliancy could be advertised - "this works with that!"

Then nobody would buy 2.3 308 ARs to get one working one.

[jtallen83]

1 hour ago, FOGeologist said:

Then nobody would buy 2.3 308 ARs to get one working one.

Look at this way, you're only a few parts shy of another rifle and with the new experience the odds of getting the correct parts are good, before you know it you'll be rounding that .3 up for another one!

[Armed Eye Doc]

16 minutes ago, jtallen83 said:

before you know it you'll be rounding that .3 up for another one!

That's how it starts.  Pieces that have no home are a dangerous thing in a gun parts bin.  They tend to grow.

[FOGeologist]

4 hours ago, dpete said:

Welcome to the 308 AR world of no milspec.  Where you can begin a build with all the major parts from the same manufacturer thinking your good to go, only to find said manufacturer fukced up one of the parts. 

 

55 minutes ago, Armed Eye Doc said:

That's how it starts.  Pieces that have no home are a dangerous thing in a gun parts bin.  They tend to grow.

You ain't kiddin', brother. I may try to keep that carbine buffer & tube, stock and spring... I have an unbuilt Anderson AR-15 upper just sitting around. I could take an Aero blem AR-15 lower ($69), a Faxon Pencil, and buy one of those Toolcraft BCGs and slap together another carbine AR-15.

Might cost $350 when all is said and done.

Or wait - a 300 Black Pistol!

[dpete]

2 hours ago, FOGeologist said:

 

 

Or wait - a 300 Black Pistol!

Now your talking.

[98Z5V]

On 9/16/2022 at 4:45 PM, FOGeologist said:

You know what would be great? If even one word you wrote was wrong. Even a little bit.

But it's not. 

I wish some sort of sanctioning body could set the configurations up to be reliably interoperable and CORRECT. Then a measure of compliancy could be advertised - "this works with that!"

Then nobody would buy 2.3 308 ARs to get one working one.

Maybe it wouldn't have been 2.3 guns worth of parts...   had you listed to the information that was provided to you right off the bat?...  Just maybe... 

[FOGeologist]

So, I bought those parts years ago. There have been multiple iterations of this build. I just found this site and signed up for it a month back or so. All the recent parts I bought before I changed my mind about the buffer system and stock were never installed and returned to the retailers.

If I'd found this site over half a decade back when I started this affair, it might have been easier.

So it's not like I ignored your advice. You don't have to try to score any points over it.

[FOGeologist]

Update: all new parts are on the lower and everything function checks well. The lower is ready to go.

The upper is waiting on the correct-length (15.5") Armalite gas tube, as the AR-15 tube wasn't near the halfway point on the cam cutout. I am also waiting on the bedding (0.001") stainless foil which I will thermofit the upper to the extension. Then it's a simple reassembly and test-firing.

[98Z5V]

17 minutes ago, FOGeologist said:

You don't have to try to score any points over it.

I'm not worried about that in the least - not at all.  Just so you know. 

I don't "score points" here, besides warning points.  I help guns run, people listen, or they don't.  I could care less how it comes out.

I know where to spend my time, though, who to help, and when. 

Inflate yourself however you may.  I'm not even concerned. 

[98Z5V]

14 minutes ago, FOGeologist said:

I am also waiting on the bedding (0.001") stainless foil which I will thermofit the upper to the extension.

That shiit is a waste of time.  JMHO.  You'll never know if it did you any good, until you can out-shoot one of your own guns.  And have to fix the gun after that, to keep up with YOU.  Good luck. 

[98Z5V]

FOG, just so you know, I build engines, transmissions, and differentials for a daily job.  Military was a daily job for 20+ years, before that.  I've turbocharged shiit that never came with a turbo, and tuned it, with nitrous injection, running on methanol as a primary fuel.  I've done water-meth injection.  And tuned it. 

Guns are my release, my side hobby, because they're not as complicated.  They're EASY to figure out.  The math is FAR more simple, for guns, over calculating a new combustion chamber volume and compression ratio (static or dynamic), for an over-bored piston for forced induction.  I've turbo'd carbed vehicles, which many say can't be done.  Done it.  Won races with them, too.  Turbos through carbs is easy business, if you know what you're doing with the carb.   

Do you even know the difference between an interference-fit, press-fit, and thermo-fit?

The barrel to receiver is NOT a thermo-fit.  Just so you know.  I deal with press-fit, interference-fit, and thermo-fit all the time.

Good luck, with what you think you know - and, you're over-thinking this thing the whole way through - at least here.  No matter how many years you've been working on this project of yours. 

Edited September 18, 2022 by 98Z5V

[Matt.Cross]

^^^ 

That's Tom-ass. Nice enough guy, super knowledgeable about the AR and platform variants. Doesn't have the vaguest clue as to how to not sound like a self-absorbed dick on the internet. Most of us have given up even trying to understand for ourselves why we're friends, we just know we love him, and we are keeping him warts and all.

That said, don't get put off by his complete lack of social skills, (bear in mind, you're being told this by a homeschooler, no less) he's a great source of advice. He probably won't even mind if you patronize him so long as it means you are paying him some attention, and don't make your condescension too obvious.

All that to say we genuinely want you to feel welcome as a newcomer, so take some of our abrasiveness with a grain of salt, it's well intended if nothing else.

[FOGeologist]

He does seem... kind of autistic.

I appreciate his knowledge, but I'm not some dippy 19-year-old kid that needs to be talked down to. I've been turning some kind of wrench for over 40 years on everything from cars to rc airplanes to guns myself.

But whatevs. I'll build my gun and see what happens. The journey, in many cases, is more instructive than the final destination. That is the whole point of the thread.

 

[Matt.Cross]

On 9/18/2022 at 11:08 AM, FOGeologist said:

He does seem... kind of autistic.

I appreciate his knowledge, but I'm not some dippy 19-year-old kid that needs to be talked down to. I've been turning some kind of wrench for over 40 years on everything from cars to rc airplanes to guns myself.

But whatevs. I'll build my gun and see what happens. The journey, in many cases, is more instructive than the final destination. That is the whole point of the thread.

 

You'll get it sorted out, there's a wealth of information and solutions to be found here. Everyone here, including Tom, wants you to have a fully functional rifle suitable to your intended purpose.

Unfortunately we've had a rash in recent times of folks who join up, ask questions, and ignore or argue everything they're told by folks who have firsthand experience in making this platform run like a Singer sewing machine.

The truly important thing here is publish your results. Priority number one is reliable data that will result in other newcomers finding what they need to fix their platform. 

If your solution works great for about six weeks and then breaks down, publish it for everyone's benefit. If it's still humming right along 1, 5, 10 years from now, publish your data, we love a success story.

My final thought on this is that we admittedly get somewhat jaded after seeing the same scenario repeat itself time and again, we get a newcomer who has gotten bitten by the non-standard nature of the platform and they want their build to work but won't take advice from folks who were in the exact same situation and have viable solutions. That becomes what's anticipated of newcomers and we aren't always as fair as we would otherwise be.

So bear with us, we'll help you 100% to the fullest extent that you'll allow us.

[FOGeologist]

9 minutes ago, Matt.Cross said:

You'll get it sorted out, there's a wealth of information and solutions to be found here. Everyone here, including Tom, wants you to have a fully functional rifle suitable to your intended purpose.

Unfortunately we've had a rash in recent times of folks who join up, ask questions, and ignore or argue everything they're told by folks who have firsthand experience in making this platform run like a Singer sewing machine.

The truly important thing here is publish your results. Priority number one is reliable data that will result in other newcomers finding what they need to fix their platform. 

If your solution works great for about six weeks and then breaks down, publish it for everyone's benefit. If it's still humming right along 1, 5, 10 years from now, publish your data, we love a success story.

My final thought on this is that we admittedly get somewhat jaded after seeing the same scenario repeat itself time and again, we get a newcomer who has gotten bitten by the non-standard nature of the platform and they want their build to work but won't take advice from folks who were in the exact same situation and have viable solutions. That becomes what's anticipated of newcomers and we aren't always as fair as we would otherwise be.

So bear with us, we'll help you 100% to the fullest extent that you'll allow us.

Roger that, Matt. The key to all these problems seems to be three or four things - buffer tube depth and buffer size, spring rate, gas port size, and gas tube length. The desire to put collapsible stocks on these rifles, coupled with the puzzling desire for idiot manufacturers to make them halfway like AR-15s, and the weird placement and size of gas ports means that everybody gets a shitty experience. 

That being said, I don't think people should try to build these rifles without reading this site. There isn't that much variation between what works, but seemingly endless confabulations of gear that DOESN'T. 

[Matt.Cross]

On 9/18/2022 at 11:53 AM, FOGeologist said:

Roger that, Matt. The key to all these problems seems to be three or four things - buffer tube depth and buffer size, spring rate, gas port size, and gas tube length. The desire to put collapsible stocks on these rifles, coupled with the puzzling desire for idiot manufacturers to make them halfway like AR-15s, and the weird placement and size of gas ports means that everybody gets a shitty experience. 

That being said, I don't think people should try to build these rifles without reading this site. There isn't that much variation between what works, but seemingly endless confabulations of gear that DOESN'T. 

I couldn't agree more. The complete lack of a platform uniform standard is definitely a long standing trope here, and is pretty much the crux of what puts people off the platform.

With that said, there's also quite a bit of versatility allowable in the platform if you understand some fundamental rules:

Buy matched receivers. There's not really any reason not to, and "that's not what I want" isn't a compelling argument.

Understand which primary type your receiver is (DPMS/Armalite/RRA/Proprietary) and buy corresponding parts accordingly. Life gets difficult when you buy a upper with an Armalite receiver cut but the handguard threads are cut on DPMS thread pitch, and vice versa.

If possible, use the Armalite recoil system, if there is a standard for the platform, it's this.

Set realistic expectations. You won't build a gun that's sub-MOA out to a thousand yards AND set a record for light weight. Your CQB 308 and your long range 308 will necessarily be different builds.

Lastly, stick as closely as possible with a uniform parts standard. Use either DPMS pattern or Armalite as thoroughly throughout as possible. Tolerance stacking is a real issue for this platform and type consistency will minimize problems arising from tolerance stacking.

 

Now that's not a comprehensive list by any means, and my fellow members can add plenty to it, but if you go forward following those recommendations it'll probably be much smoother sailing in general.

[98Z5V]

2 hours ago, FOGeologist said:

He does seem... kind of autistic.

Keep up the insults - see how far you can run with that one. 

[jim3326]

2 hours ago, Matt.Cross said:

I couldn't agree more. The complete lack of a platform uniform standard is definitely a long standing trope here, and is pretty much the crux of what puts people off the platform.

With that said, there's also quite a bit of versatility allowable in the platform if you understand some fundamental rules:

Buy matched receivers. There's not really any reason not to, and "that's not what I want" isn't a compelling argument.

Understand which primary type your receiver is (DPMS/Armalite/RRA/Proprietary) and buy corresponding parts accordingly. Life gets difficult when you buy a upper with an Armalite receiver cut but the handguard threads are cut on DPMS thread pitch, and vice versa.

If possible, use the Armalite recoil system, if there is a standard for the platform, it's this.

Set realistic expectations. You won't build a gun that's sub-MOA out to a thousand yards AND set a record for light weight. Your CQB 308 and your long range 308 will necessarily be different builds.

Lastly, stick as closely as possible with a uniform parts standard. Use either DPMS pattern or Armalite as thoroughly throughout as possible. Tolerance stacking is a real issue for this platform and type consistency will minimize problems arising from tolerance stacking.

 

Now that's not a comprehensive list by any means, and my fellow members can add plenty to it, but if you go forward following those recommendations it'll probably be much smoother sailing in general.

Then there's the DPMS hi and low rail.

[FOGeologist]

48 minutes ago, 98Z5V said:

Keep up the insults - see how far you can run with that one. 

I know you enjoy a protected status on this site due to the knowledge you've acquired. But at this point I am contemplating blocking you, because you act like an child.

Kindly get out of my thread.

[Matt.Cross]

On 9/18/2022 at 2:23 PM, jim3326 said:

Then there's the DPMS hi and low rail.

 

Yes, as if the platform wasn't convoluted enough to begin with....

[FOGeologist]

13 minutes ago, Matt.Cross said:

 

Yes, as if the platform wasn't convoluted enough to begin with....

Ah, jeeze, I had forgotten about the rail height issue! With every manufacturer seeking to "solve problems" by creating a varing type of rifle, there are probably myriads of weirdo combinations of components, a sizable number of which could produce guns that either look weird and function fine, look great and malfunction dangerously, or just hardly function at all.

[98Z5V]

2 hours ago, FOGeologist said:

I know you enjoy a protected status on this site due to the knowledge you've acquired. But at this point I am contemplating blocking you, because you act like an child.

Kindly get out of my thread.

Fuk off - block me then, you whiner.  You don't know anything about me.

[jtallen83]

Just now, 98Z5V said:

You don't know anything about me

and he never asked.........

[Matt.Cross]

I'm getting some serious thread-cleaning foreshadowing here. If it's not too much to ask, a modicum of effort to stick with the thread topic.

Everybody do yourself a favor and hit the 'reset' button on your grudge list, please, lest I get all trigger happy with the 'mute', 'edit', and 'delete' functions, or worse.

First and only warning, play nice. I like y'all but Admins gotta Admin.