AR build

[kukurilynch 2]

I have been thinking of building a AR 15 what is a good 80% lower to start with? I would ask a AR forum but i never get a good answer. So i am asking you all.

 

[Mullet Man 2,114]

Silly to work an 80% at the prices fully machined lowers are going for.

[Hawk451 2,230]

Tactical Machining blanks worked in a 80-lower jig have turned out good for me. I've heard good things about Modulus Arms too.  Moderate mechanical aptitude required. Watch the youtube vids and follow instructions.

 

Economically, Mullet Man is right. Pretty tough to beat current prices on 100% lowers. But, there's a certain satisfaction in shooting a rifle (or pistol) that you finished.

 

If you haven't already, check out ar15armory : Good bunch of knowledgeable folks who don't 'bash the new guy'. 

[Heartbreaker 1,085]

Having done an 80%, I would only do it again if I had a milling machine. Even then, an Anderson lower for ~$55 would be my first choice.

[XD45 7,124]

Anderson lowers go on sale for $39 from time to time. Impossible to beat that economically.

[HB of CJ 1,263]

Unless you know what you are doing it may, (MAY) just be easier and better to decide what you want then have one of the many manufactures or precision builders build your AR15.  It is what you do not know what you do not know.  I for one would not attempt an 80% lower.

 

In my situation a new Left Hand 6.5 Grendel Heavy Barrel 20" Rifle beckons.  All the necessary and nice, (optional) gadgets, gages, tools, facilities and the rifle range are not available to me right now.  It would cost some bucks to re establish everything necessary.  Spendy for me.

 

But .... if you are in the top one percent of mechanical ability individuals and have ALL the things necessary, then perhaps a 80% lower would work for you.  It would not work for me.  The lower has to be perfect to work perfectly.  The actual build requires knowledge and experience.

 

Respectfully.  Hundreds of AR15 builds.  Yikes!

[patriot 7,197]

Polymer80s are nice. I've used them.

(here we go again)

[XD45 7,124]

When it comes to building an AR the knowledge is readily available for free if you want it. There is more to a reliable build than many realize but anybody with basic mechanical skills can do it well if they put in the effort.

 

I haven't done an 80% and probably wouldn't without a mill. Otherwise too tedious and the resusulting receiver wouldn't be as nice as the $39 Anderson receivers I've used.

[HB of CJ 1,263]

"Oh, I finished my own build.  Hammer, barrel wrench, vise grips, screwdriver. Now I am going to test fire it.  Hey you all, watch this!" ...

 

BOOM!!!    AUUGGHHHHH!  :)   (meant to be funny and not start a shit storm)

[patriot 7,197]

"Oh, I finished my own build.  Hammer, barrel wrench, vise grips, screwdriver. Now I am going to test fire it.  Hey you all, watch this!" ...

 

BOOM!!!    AUUGGHHHHH!    (meant to be funny and not start a shit storm)

Not everyone is a ham fisted hack, and insulting those who CAN  and DO roll their own is pretty damned arrogant....

 

...and many, many more,...but you get the idea...

 

My 80% Polymer80 build malfunctions after hundreds of rounds fired, handloads and factory? ZERO to date.

My factory lower guns malfunctions? A few.

YMMV.

 

No, I don't have a mill. Just some good, solid, basic tools, patience, and skill.

Many people have the skill. Some have yet to discover it. Some would rather bash others than try to help.

They only need to try.....

Edited April 29, 2017 by patriot

[BigChongus 765]

Andersons are $35/ea today from Primary 

[XD45 7,124]

Andersons are $35/ea today from Primary 

There ya go.

 

But I can't afford any more "cheap" lowers.  My 3 $39 Anderson lowers each turned into $2,000+ rifle builds.

[BlackHeart762 288]

I get a kick from people making rifles from 80% lowers (so the gubment dont know I has it)

 

Then they post pictures and comments, questions ect.

Not to mention the search history....LMAO

 

If we ever get to the place where guns are being rounded up, having one on a 4473 form would be the least of your worries.

 

BH

[XD45 7,124]

As of right now the government can't be sure what guns I have because we are still free to buy and sell without government approval.  They may know how many guns I've bought on a 4473 (and never doubt they keep that information despite the law requiring them to delete it).  They for sure know what nfa items I have.  But they don't know how many guns I've sold or bought person-to-person. 

 

That is our defense against confiscation.  The government realizes this too, and that's why the push for "universal background checks".  So no gun can ever change hands legally without going in the database.   "Universal background checks" is registration.  So if you say you will never register your guns then that must include never accepting ubc.

[jerry52 893]

When it comes to doing a build with a 80 % lower most do it for the fun not to save a ton of money.

Have fun take your time. Polymer lowers work good for the beginner

[HB of CJ 1,263]

Once we did a field expedient AR15 barrel change at a gunshow in under 3 minutes.  But ... we knew the pieces would go together perfectly and head space correctly which we checked anyhow.  Drew of crowd of admiring onlookers.  Fun.  A trained monkey can assembly AR15 rifles.  But ... to do a precision build one needs to know what one is doing. 

 

For example .... seven, (7) different head space gages?  How many barrel gages?  Receiver dressing and lapping tools?  How long did it take Old Coot to index that pesky barrel?  Too darn long!  Off and on.  Off and on.  Yikes!!  But ... all easy and fun once your know how.  Oh boy.  This is meant to be funny.  No shit storm intended nor implied.   

 

An eighty percent (80%) build?   Not for me.  I do not have the machinist skills.  Yikes!

[BlackHeart762 288]

indexing an AR barrel?

[HB of CJ 1,263]

M16 or AR15 barrel indexing for those who do not know or understand ... is the following ...

 

No slam dunk here.  Passing it forward.  It means precision rotating of the barrel sosss the horrible AR15 OEM taper pin iron sights line up perfectly right to left with the build shooting exactly down the pipe on the 100-300 yard bench rest.

 

The problem starts with the barrels not being quite correct.  But if you must get that barrel to work on that build you have to go through heck to get things to line up properly.  Properly meaning within 2-4 clicks of rear aperture dead center.

 

Done by mathematically determining how much the barrel must be physically rotated. (just a tiny bit)  Usually shimmed with precision thickness shim stock between the barrel tit and the receiver slot.  Usually material removed from receiver

 

This translates to just a very small small sub thousandths of one inch at the bolt lug barrel extension lug interface.

 

No rear site cant.  Everything perfectly even..  The up and down is normally not a big concern.. Just a front site blade change out, adjustment or filing down.  Keep filing until the front post is long enough.    Yikes!  No dog.

 

hundreds of builds  uncounted rebuilds.

[Sdustin 578]

Ever seen a barrel headspace​ wrong on in spec ar15 parts? Doubt it. Most people just want a decent rifle not a nra high-power comp gun. Building an ar15 is super easy and can be done with some wood blocks a vise and barrel wrench hammer and some punches.

[HB of CJ 1,263]

Actually ... no.  Again it is what you do not know what you do not know.  Not trying to start a war.  Just the truth of it.

 

Edit:  Back on topic, this relates to the unknown pitfalls and perils of an eighty percent lower build.  Lots of dimensions MUST be perfect.  Difficult to do with a 80% lower.  Even I would not try it.  But ... I understand why.  Again ... no dog.

 

Respectfully.

 

Edited by HB for speelling.

Edited April 25, 2017 by HB of CJ

[BlackHeart762 288]

M16 or AR15 barrel indexing for those who do not know or understand ... is the following ...

 

No slam dunk here.  Passing it forward.  It means precision rotating of the barrel sosss the horrible AR15 OEM taper pin iron sights line up perfectly right to left with the build shooting exactly down the pipe on the 100-300 yard bench rest.

 

The problem starts with the barrels not being quite correct.  But if you must get that barrel to work on that build you have to go through heck to get things to line up properly.  Properly meaning within 2-4 clicks of rear aperture dead center.

 

Done by mathematically determining how much the barrel must be physically rotated. (just a tiny bit)  Usually shimmed with precision thickness shim stock between the barrel tit and the receiver slot.  Usually material removed from receiver

 

This translates to just a very small small sub thousandths of one inch at the bolt lug barrel extension lug interface.

 

No rear site cant.  Everything perfectly even..  The up and down is normally not a big concern.. Just a front site blade change out, adjustment or filing down.  Keep filing until the front post is long enough.    Yikes!  No dog.

 

hundreds of builds  uncounted rebuilds.

Good thing I have hip waders on

Bh

[HB of CJ 1,263]

Oh boy.  Here we go again.  Never send an UN-knowledgeable to do a skilled job.  This includes a home done 80% AR15 lower build.  Just who are the hip waders for? 

 

Respectfully ...  NO DOG.

 

If you do not believe or understand something you do not resort to back handed criticisms of such?  Instead you tell the gentleman explaining it you do not yet know or understand.

 

Back on the 80% build.  It is my understanding that some precision holes much be bored through the receiver.  Fire control group holes, mag catch hole, take down pin holes?

 

Perhaps other holes, slots, channels, etc..  The mag well must be very exact also.  It can have tooling marks, but the finished job has to be very precise.  The whole thing must be.

 

With the proper tools and knowledge/experience an 80% lower can be finished by many methods.  But ... it all has to come together correctly.  Consider also that the receiver ...

 

Is only part of the AR15 build.  Other stuff hangs off of it.  It also must come together.  Lots of mechanical interactions take place.  And ... the gun must last some high mileage.

 

A 80% AR15 build hints or suggests that the rest of the build will also be done by somebody private.  If a professional builder, then fine.  But for the home hobbyist maybe not.

 

This includes specific build experience/knowledge/wisdom needed to build other parts of the rifle.  Specifically the barrel torquing/indexing.  Which is why I touched upon that part.

 

My point in this.  We kinda got side tracked.  The side track was intended by me to illustrate the builder must understand lots of stuff.  For most an 80% build is beyond that point.

 

Respectfully. 

[jerry52 893]

You make some good points but everyone has to start somewhere.

[HB of CJ 1,263]

Exactly correct and thank you.  My baddy.  Even a long prosperous life begins with that very first step.  One of the things I find hard dealing with is now I am an Old Coot and my job in life is passing stuff forward.  Just like my Dad who tried.  And his Dad.  And his.  And so on.

 

But sometimes I regret knowing what I know.  Wish I had a whole lot more life experiences with many other things besides guns.  Gourmet cooking.  Master gardening.  Farming.  Pure school teaching.  Longer public service.  Better medical skills.  But ... plenty of time yet. 

 

Respectfully.

[G O B 3,516]

It is EXTREMELY arrogant to deride those who must use hand tools. Watches (the BEST) are made with hand tools. It would destroy your tiny mind to know just how much space hardware is hand made or fitted!

 

The bullshit is boat deep in here!

[HB of CJ 1,263]

G O B:  Shame on you?  Dunno about that.  You need to decide, not me or others.  Is it arrogant for one to try to pass forward hard earned and won life skills?  Particularly regarding somewhat useless firearm skills?  Especially in particular AR15 rifle building skills?  I do not think so.

 

If it tickles YOUR inflated ego, then I humbly apologize.  Or ... is this just a silly case of one who gets caught with his knowledge pants down around his ankles and just responds with killing the messenger because ... HE refuses to acknowledge that there is something new to learn?

 

When YOU have built over 225 precision AR15 rifles and assisted in literally uncounted team tackled beater M16 rifles, (uncounted because frankly I do not know the exact number) and have learned both the easy way and hard way what works and what does not work then perhaps ...

 

... You can try to chip in here and add some meaningful, accurate and timely tips and recommendations regarding a 80% AR15 build.  The first poster was just asking for our advice.  Some here have AK build skills, others like me have extensive AR building skills.  I am trying to help.

 

Respectfully.

Edited April 25, 2017 by HB of CJ

[russm4a3 5]

80% are not hard to do if you have a drill press,a router, and a 80% jig but it does take time. Most of the sites selling the lowers sell the tooling necessary to complete them. I would get one of the 80s that have the rear of the receiver milled out a bit already, saves time.

[G O B 3,516]

I would NEVER build a :precision" AR rifle - it would be a waste of my time. A DECENT AR shooter, THAT is something I will do if I can ever get the shop built. I will do it on an 80% receiver, JUST BECAUSE I CAN!

 

My beef is with the people who cannot do it, and think that just because YOU can't, that no one else can! You are related to those assholes  that want to make it against the law to work on your own car or tractor. (YES, I CAN code in assembler, and even get the hexadecimal addresses right!)

 

Making ONE of nearly anything can be done with some simple tools. Making 5,000 of the same is a LOT quicker with a CNC 5 axis mill!

 

Additive manufacturing will change that soon, as it allows the creation of designs that are otherwise impractical ( an aluminum receiver with .010 inconel at all wear points and surfaces), but for NOW most designs were constrained by what can be done with conventional tooling. - and can be made by hand with careful measurement and much time.This shit is NOT "magic" just simple processes and much attention to detail!

[gunfun 3,931]

I get a kick from people making rifles from 80% lowers (so the gubment dont know I has it)

 

Then they post pictures and comments, questions ect.

Not to mention the search history....LMAO

 

If we ever get to the place where guns are being rounded up, having one on a 4473 form would be the least of your worries.

 

BH

 

It ain't the gubmit for all of us. In WA that $39 lower gets taxed and the LGS will tack on $30 for doing the background check.

 

Buying a dozen 80%s for next to nothing and having a gun whenever you want without asking anyone's permission is the appeal. 

 

I know people who want to not be on the lists in CALI and I promise you they aren't posting about it on line. IMO that's a pretty valid reason.

 

For me the choice is simple. Rights not exercised are lost. Economically complete lowers are cheaper. But I like the idea that I can make my own.

Oh and no possibility of the transfer on your blank lower being marked rifle when you want to use it for a pistol build.

[HB of CJ 1,263]

80% AR receiver builds.  It is possible for the knowledgeable, skilled and equipped machinist hobby guy to mill and drill out his own 80% receiver.  Let's concentrate on that which was the original question from the thread poster.

 

AR15 80% builds.  As a hobby endeavor quite doable if one knows what one is doing.  Could I do it?  Dunno.  Maybe.  Probably.  But maybe not either.  Lots of dimensions would have to be within correct specification.  Yikes.

 

I would not be sure of what was completed.  Too much could go wrong.  Or not quite exactly correct.  Would I trust that home made 80% lower?  No, I would not.  But doable for others?  Could be.  The results?  Dunno.

 

So there you have it.  I have not done an 80% lower.  Have no desire to.  But if others have done it and are happy and if the guy who posted the first question wants to do one, then do it.  This post/thread has run its course.

 

Respectfully.  About 225 precision AR15 builds.  This is from memory. From some of the not nice responses to my AR15 tips, the total AR15 build level knowledge on this forum MAY be lacking.  Take it or leave it.