Small frame AR build thread

[Solid_Squirrel]

This is my first DIY build. I will hopefully learn, and get the tools I need, as I go along. I have a basic workshop, drill press, torque wrench, hammer, wood screws, JB weld, etc.

So I'm only still just collecting parts, in no particular order. I'm also trying to decides on the caliber/chamber to use something in 6mm or 6.5mm perhaps, even a wildcat. I live out in the woods. Pretty sure I have at least a 500 yard "lane", and it goes uphill, with a river at the bottom and woods on the other side, as well as other berms where the clay was dug out - you see what I'm getting at - it's perfect for target shooting.

Mega Billet Side-Charger, 7075
Nightforce Unimount Ultralight, 7075, 6AL-4V 1.125"/30mm/20MOA
YHM muzzle brake
Phase 5 ABL/CHA
Phase 5 EBRV2-SC

I have a question is about the Phase 5 extended bolt release - I have read that these extended bolt releases can prevent the bolt from locking back after the last shot - anyone experience this kind of thing? I guess I will see.

ETA: I'd also like to find out who the better gunsmiths are within the state, for the things I might not be able to do (machining and so on)., and just because.

 

[KillShot]

Re: Small frame AR build thread

Damn! The teeth on that charging handle look as if they'd chew skin right off your fingers and maybe even double as a limb saw!

 

[Solid_Squirrel]

Re: Small frame AR build thread

It would be, but there isn't a non-radiused edge on the thing, so it's quite comfortable. But I was thinking it would still work with gloves. It gets cold here.

 

[Beef_Supreme]

Re: Small frame AR build thread

Does the bolt release clear in the notch on the billet upper?

 

[Solid_Squirrel]

Re: Small frame AR build thread

No it does not, not the whole thing at least - from the pictures I saw, I wasn't su
re if that was a problem, as it seems to be canted out when installed - will that need to be clearanced or used on a different project? It looks like I might be able to grind a little bit off of the EBR, I could do it precisely.

I'm looking at the picture on this page:
http://phase5tactical.com/products/ar15-m16/extended-bolt-release-v2-side-ch-ebrv2-sc

It doesn't seem to fully clear the notch here either, so I thought it might be ok, but I wouldn't know. I'm not sure whether it will clear a billet Mega lower either.

 

[Beef_Supreme]

Re: Small frame AR build thread

Excellent question, let me know what you find out. I have built a LOT of Mega upper, lowers, and Monolithic uppers as well, but never put one of these on for any of those builds. Maybe someone with some experience in the mating of the two beasts will have some insight.

 

[Redmanss]

Re: Small frame AR build thread

A few questions here....

Why do you have that oversized ambi charging handle for a side charging upper?

Is this your first rifle, or do you have more to shoot in the meantime?

What machining are you expecting? Are you going to be buying a barrel blank and turning it yourself? Otherwise, there isn't anything to machine on it. ARs are fairly straight forward "buy and bolt" assembly with minimal fitting required.

For parts, are you attempting to go with the "ultimate tacticool" mindset? That's fine if you are, but if you're on a budget it's pretty hard to do in a timely fashion.

As for the extended bolt release, I don't run them but I have read of some having locking issues due to the added weight. The only way to find out if you will have that problem is to run it and see. I'm not a fan of anything else in my trigger guard area.

 

[Solid_Squirrel]

Re: Small frame AR build thread

Ha, that's a good question. I liked these two parts, which I ordered directly from Phase 5, so I got them both at once. I guess you could say the theme of this build is that it's purely for my amusement. The things that I'm interested in, are load development, as a general concept, how a gasser functions mechanically, how the parts work together.

It's more like the "ultimate boredom mindset", ha. Purely for my own amusement and enrichment. I just like to tinker, and understand how things work. I like to learn new skills. This is my first ever. I shot a lever action .22 over 20 years ago, that's it. I'm from MA originally. It's different here, I here gunshots constantly were I live.

I know there <span style="font-style: italic">shouldn't</span> be any machine work, but I like to endlessly mess with things. It's good you said this, I swear I let the scope of every project creep as much as possible, as though I am actually avoiding it's completion subconsciously. So while efficiency is not required, I appreciate your reminder of it's existence. I like to do experiments, I have done it with a computer, I'm doing it with a car - I like to have a testbed to help me learn about the nature of that thing, and what optimizes or compromises it's function and performance.

But yeah, I like hobbies involving mechanical or technical things - and I'd like to be able to someday say "I understand firearms" - know what I mean? Thanks for your thoughts.

ETA: Just remembered what made me think of machining. I was reading about how Robert Whitley checks and corrects that the face of the receiver is square to the bore/threads, but that most of them aren't. Now, of course nothing is perfectly square to anything, so I'm not sure what kind of tolerance we're talking about.

 

[Redmanss]

Re: Small frame AR build thread

You shouldn't have an issue with the squareness of a billet receiver. They're cut pretty dang precise.

I'll say this on the parts selection. It's easy to get carried away when building an AR. There's so many modifications and upgrades out there that the market is overflowing in options. While that's not necessarily a bad thing, it definitely causes you to have to think about the cost : benefit ratio. I like B.A.D selector levers, but not enough to justify $55 for each rifle of mine. That's a lot of ammo. The same can be said about a lot of other options too. The challenge is to be able to tell the difference between gimmicks and practical implements, and that still comes down to personal preference.

I'll add this one last note. Focus on a quality barrel and trigger. That's primarily where your rifle's accuracy is going to come from. On assembly use the right tools for the job, and pay someone when you don't have that available. I still send my uppers out to be barreled just to make sure it's done right the first time, and someone has to help these gun plumbers put food on the table....

 

[redirt78]

Re: Small frame AR build thread

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KillShot</div><div class="ubbcode-body">Damn! The teeth on that charging handle look as if they'd chew skin right off your fingers and maybe even double as a limb saw! </div></div>I agree, the one that came with my POF308 was a lot like that. I swapped it for the Vltor Gunfighter mod3 and its a lot nicer, smoother and easier to rack especially with the big scope. I won't run mine with gloves unless its really cold so the limbsaw version sucked for me.

 

[Solid_Squirrel]

Re: Small frame AR build thread

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Redmanss</div><div class="ubbcode-body">You shouldn't have an issue with the squareness of a billet receiver. They're cut pretty dang precise.

I'll say this on the parts selection. It's easy to get carried away when building an AR. There's so many modifications and upgrades out there that the market is overflowing in options. While that's not necessarily a bad thing, it definitely causes you to have to think about the cost : benefit ratio. I like B.A.D selector levers, but not enough to justify $55 for each rifle of mine. That's a lot of ammo. The same can be said about a lot of other options too. The challenge is to be able to tell the difference between gimmicks and practical implements, and that still comes down to personal preference.

I'll add this one last note. Focus on a quality barrel and trigger. That's primarily where your rifle's accuracy is going to come from. On assembly use the right tools for the job, and pay someone when you don't have that available. I still send my uppers out to be barreled just to make sure it's done right the first time, and someone has to help these gun plumbers put food on the table.... </div></div>

I believe what you say about the billet receivers, now that you mention it. If they have no other advantage, they should have good dimensional consistency and accuracy. What you say all makes a lot of sense.
When it comes to forged vs. billet; say, for the internal parts of a 1000 horsepower engine - you can use forged or billet, these will both hold up to tremendous cylinder pressures. So I kind of hoped/figured that this billet receiver is not <span style="font-style: italic">both</span> heavier, <span style="text-decoration: underline">and</span> not as strong, due to just having it's natural grain structure, unlike a forging, where it is optimized - but that it's a little heavier and of similar strength.
I agree, I feel good about supporting craftsmen and small business.

 

[Solid_Squirrel]

Re: Small frame AR build thread

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: redirt78</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KillShot</div><div class="ubbcode-body">Damn! The teeth on that charging handle look as if they'd chew skin right off your fingers and maybe even double as a limb saw! </div></div>I agree, the one that came with my POF308 was a lot like that. I swapped it for the Vltor Gunfighter mod3 and its a lot nicer, smoother and easier to rack especially with the big scope. I won't run mine with gloves unless its really cold so the limbsaw version sucked for me.

</div></div>

I'd actually recommend this for bare-handed use, as much as I can, having only <span style="font-style: italic">fondled</span> it, without having used it. Here is a macro shot so you can see the radiused edges. Maybe I just haven't put it through it's paces properly, but it doesn't seem like it's gonna be a problem. If you handle it, you can tell the focus was on ergonomics.

 

[kaptain86]

Re: Small frame AR build thread

From what I've found with a larger charging handle is that it can get in the way when carrying with a sling. Something to keep in mind when adding it on. I have a badger charging handle and it digs in sometimes.

 

[Solid_Squirrel]

Re: Small frame AR build thread

I was hoping it wouldn't since the < part of the latch would face out when slung, instead of like this >, as seems to be typical. I was thinking I could make a little corner of canvas into a cover that could slip over the latch, to keep it from snagging, but could come off quickly and stay tethered.

The above orange knob may become a hand stop or something, I've come up with a new side-charging knob design. I'm not familiar with how much effort it takes to charge one of these, but if it ends up needing to be a little longer, it's easy to make that change due to this being a stack of glorified washers on a screw, along with a nut or two (all 7075 currently; I may replace the screw with a steel one). This one is more low-profile and lighter.

 

[Solid_Squirrel]

Re: Small frame AR build thread

ETA: Knob shown above sticks out about 7/8", and is almost 1/2" in diameter.

Anyway, someone asked me in the shoutbox the other day, what barrel I'd be using, which I'd not yet decided. Well, now I've decided: I'm going with a 6.5mm BRX, 20", Krieger Criterion, 1 in 8" twist, 410 stainless, SPR profile, rifle gas, from ar15performance.com (with 9310 "superbolt", and the barrel extension). The deciding factor for me is ar15performance's bolt design.

Anyone have any thoughts about the caliber, barrel, or anything else? Don't hesitate - I would not have posted this on the internet, if I was not comfortable with criticism, contrarians, or pedants, as well. I'm glad we were able to have this little talk.

 

[Solid_Squirrel]

Re: Small frame AR build thread

Made my own multifunction sling from scratch:

 

[Solid_Squirrel]

Re: Small frame AR build thread

Progress. Confronted with my inexperience, I decided to go a slightly more simple direction.

AR Performance 16" SOCOM .223 Wylde; 1 in 8 twist Hybrid 5R rifling, 5/8-24 muzzle thread and double stress relieved to enhance accuracy; 11595-e mil-spec CMV alloy; nitro-carburized(QPQ), gas port drilled, mid length gas system;

AR Performance 5.56mm 9310 Superbolt

PWS DI Bolt Carrier; S-7 tool steel; Isonite QPQ coating

 

[Solid_Squirrel]

Re: Small frame AR build thread

Oh, here are some pictures of the 9310 steel bolt. They sell these for almost half what a 9310 bolt costs elsewhere ($85 vs. the $150 I've seen two other places).

Slash's Heavy Buffers, HSS Tungsten Carbine Buffer 6.5oz (the PWS DI S-7 steel carrier weighs 9.9oz, FWIW)
Wolff XP Buffer/Action Spring #16501
Spacer for using carbine buffer in rifle buffer tube/receiver extension

 

[BittenbytheBug]

Re: Small frame AR build thread

Well - I will say that you picked your barrel/bolt combo from an outstanding firm. Harrison is very good at what he does and my 6.8 barrel/blot from him is simply....great. I will be buying more from him.

Glad you settled into a cartridge you will enjoy and shoot some distance with.

What are you looking at for your trigger group?

 

[Solid_Squirrel]

Re: Small frame AR build thread

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rick Just Rick</div><div class="ubbcode-body">Well - I will say that you picked your barrel/bolt combo from an outstanding firm. Harrison is very good at what he does and my 6.8 barrel/blot from him is simply....great. I will be buying more from him.

Glad you settled into a cartridge you will enjoy and shoot some distance with.

What are you looking at for your trigger group? </div></div>

I imagine I'll be dealing with him again as well. I like the choices they've made about their products, and I think it even shows something about his greater underlying philosophy, which I find to be very credible and competent, which is reassuring. He also answered my many questions, which is also reassuring.

Maybe a Geissele SSA?

 

[BittenbytheBug]

Re: Small frame AR build thread

Good trigger! I run them in 2 guns - love them.

 

[Solid_Squirrel]

Re: Small frame AR build thread

Seems like the LWRC Skirmish BUIS are unique, in that they are made of 7075-T6, and 4140 (with "NiCorr" treatment), (plus hard chromed bearings and detents). Is that correct? Any other BUIS use comparable materials? Anyone have any thoughts about these sights?

I also thought these KNS crosshair front sight posts looked interesting:

ETA: I've also decided on a few more parts that I'll (most likely) use: Geissele SSA-E or SD3G. Seekins' billet lower, and a Seekins SAR or BAR handguard. PWS extruded buffer tube. LWRC Skirmish BUIS. B5 SOPMOD or Magpul STR or an Ace skeleton stock of some kind.