Budget AR 15 Build + review (blackthorne+Aero Precision+primary arms)

[yetisoldier]

I'm currently building a couple of AR's and I figured I would post a review here of how things are going and of the quality of the products.  As stated in the subject it is indeed a budget build.  My goal is to build a functional reliable AR on the cheap (well cheap for an AR). I've built one rifle before using almost the same parts I'm going to be using on these and had only one issue with it I resolved easily. Aside from finding some super great deals on used stuff in the forums, there isn't a cheaper way to build than this, believe me I looked for a while.

Alright time for the reveal.  I have two Blackthorne 16" A3 m4 kits. Yup I said the dreaded B word.  My first rifle as stated early was built on one of these kits and the only problem was an out of spec mag latch I replaced for $5. I got the kits in the mail today.  The uppers look to be in good condition( wrapped in foam, everything else in bags), no marks, Cerro forging marked uppers, and I believe the barrels had a 2 stamped into them near their base under the hand guards (they were far under and hard to see) and the front sight posts were stamped with an F. The FSP was also properly lined up with the reciever, no tilt that I could see.  The bolts looked brand new and had a thing film of oil on them.  The LPK's looked standard, cheap looking roll pins, but other than that fine.  The stock kits are six position stocks. I'm not sure if they are commercial or mil-spec, but they look sturdy. Assembly of the lower won't happen till later in the week, the recievers I ordered haven't come in yet.  I should mention I ordered these kits on a thursday and got them the next monday, so shipping was prompt (and included in the price). Though the first I kit I purchased back in late 2008 took 7 months to arrive, but that was during when everyone was sold out. I knew it was back-ordered when I bought it, but it was only suppose to be 4 months not 7.

These are going on Aero Precision Lowers. Also I bought a couple of the primary arms quad rails + magpul xtm covers. The rails looked great, no blemished, the machining was clean (not rough like I've read else where). The are a two piece clamp together style rail.  The bevelled edge slips into where the base of the hand gaurds would go and it has rounded spots that have it index to the barrel nut and prevent it from turning left or right.  The front of the rails go on the outside of the handguard holder at the front sight post.  After installing put in the four supplied screws with the supplied allen key and your good to go.  I would recommend some lock tight on the screws.  I also suggest waiting to put the rail covers on until after its installed.  I got a little eager and installed them right away and had to take them off (when not on the gun the xtm covers are a PITA to remove from the rail).  Overall I highly recommend the rails.  The only thing I noticed that I thought I would mention about them is that on my uppers they where off be like .5 mm.  Looking down the reciever from the back the right side of the quad rail was .5 mm above the rails on the receiver itself.  Its not a large amount and doesn't move so I don't think its an issue.  Like I said unless your going to war I highly recommend this rail. To round out the rifle itself I also bought a matech BUIS.  Its the same BUIS I used when I was in the army and I got a great deal on ebay.  I bought two used Matechs for $35 a piece, which is a great deal on a reliable name brand sight.  Other people don't care for them but I think they are fine.

So for all who are interested here is the low down on the cost:

Aero Precision Lower     $69 + $10 ffl transfer
Blackthorne Kit            $419
Primary Arms Quad       $50  (with shipping added in)
Matech Buis                [$37 (with shipping added in)

Grand total :             $585        (or if you want to go super cheap $535 without the rails)
(The prices about are for everything with shipping and ffl fees and stuff already added in so the grand total is the actual total cost)

Not to bad, now just to cool some flames.  I can feel people getting mad already I didn't drop over a grand on this build, and most likely it will be just fine.  This isn't my primary AR.  I have an AR built on a spikes lower with RRA LPK and 2 stage RRA NM trigger, moe grip, magpul aluminum enhanced trigger guard, new matech BUIS, troy flip up hk style front sight, Eotech 552, and I'm waiting on a Addax ZK 16" GPU  I  ordered last month.

Later this week when the lowers come in I'll review some more and perhaps post some pics, if anyone has any pic requests let me know.

Yetisoldier

Edit:April 19, 2011
I thought I would add that the same kit is $535+shipping from Model 1 and $485+shipping from Delton.  So respectively the blackthorne kit was $116+ shipping cheaper than Model 1 and $66+shipping cheaper than Delton (plus when I ordered the Blackthorne kits, Delton was sold out of what I wanted).  Just thought I would add this for people interested in what the build would cost with other budget kits.

I had some time on my hands before work so I decided to take some pics.  Also upon further inspection I noticed that the endplate for the the buffer tube has a sling point on it.  That was a nice surprise.

Here is how they arrived


Here is the bolt, if you notice it has WIB stamped on it


Left an right sides of the reciever



The front sight post


Down the chamber


Picture's of the Rails and how they mount:

I took a pic of the bottom since I don't have rail covers on it so you could see the rail itself


Finally here is a pic looking down the top of the reciever, Its barely noticeable, but if you can look you can see the slight cant of the rails.  I'm my opinion its soo small its not a big deal.


Here are some more pics of the barrel, gas tube, chamber, and barrel nut, these are from the other upper (I didn't feel like taking the quad rail off of the other one again).  Both look identical and everything is tight on both. In person the FSB shown above is straight. I think the slight cant of the rails give an optical illusion of it being off, in the picture.








When the Lowers come in I'll get some more pics and post how the build went. Enjoy.

[excaliber]

well I dont know much about all the different parts available, but your build looks nice. I will be building myself one soon.

[Goatdog62]

Great job I like low cost builds. I had a similiar thought recently.


I have a bunch of AR's but a couple weeks ago I wanted to see how cheap I could get a brand new AR for. At a gun show I bought a Plum Crazy lower for $100 and a Del-Ton 16" upper for $379. Both brand new. All it needed was a rear sight. I had a really nice A.R.M.S. #40 BUIS flip up that cost over a $100 a few years back and slapped that on there but I could have bought a Magpul flip up rear for $35 or so and some lesser brands for $18. No rails or anything else to add weight, so it is easily my lightest AR.

$497 with the no-name rear sight (which probably works fine but I don't know as I usually get nice ones.

I have spent the last two weeks trying to break it. I have not been successful. I was skeptical of a polymer lower and I won't declare it a front-line gun just yet, but I actually like the trigger pull (very crisp) and feel it is a pretty sturdy gun. Probably give it to my son but someone who was needing five of em and some ammo could do it all for under $3000. Them Zombies ain't gonna kill themselves.

[yetisoldier]

I'm glad you like it.  I still haven't gotten the lowers yet.  The guns seem pretty good. Blackthorne has a bad rep at AR15.com, because I get alot of haters there.  I'm just posting about what I have, but people don't like it.  They seem to think you need to drop $1000+ into an AR and have the name brands to match. They aren't the nicest kits in the world, but mine are good enough for the average person, and at this price point you can buy alot of ammo for the price difference.

I saw the plum loco lower, but was wary of it since its polymer, keep us updated on how it holds out. I think at a minimum it would be good for a 22lr dedicated upper.

[Cacinok]

Good write up OP.  I have a feeling a lot of people will be doing budget builds, if any, in the near future.

S&W offers an entry level ar (M&P 15 sport) for right at $700 suggested retail, but this translates to $530-$600 on the street, if you're lucky enough to find 'em. 

CMMG "bargain bin" rifles are also a pretty good at around $600.

[mike77]

I don't know a whole lot about building or using AR's, but why is Blackthorne a dreaded word?

[yetisoldier]

They have kinda of a bad reputation.  Some of it deserved and some a little exaggerated.  They have a really shitty return policy and their QC is almost non-existent.  So far I've had three kits from them with no problems, but others seem to have had big issues with canted front sight posts, barrels with multiple gas holes drilled and welded over (under the front sight post) and stuff like that.  I have a decent amount of experience with AR's so I feel comfortable checking everything over first and know what I get.  Like I said, all my kits have been good.  My main complaint is the roll pin for the bolt catch.  Its too big and almost impossible to get all the way in if you don't crush it with pliers first.  Here is the rest of the review so far:

Alright the real part of the build finally begins (I'm not posting pics of the whole LPK installation process since that can be found elsewhere).  I'm a little busy, so I only built one of the Blackthorne Lowers, and one with a PSA LPK.  So I have one more Blackthorne kit to put together later.  Here are some pics of the aero precision lower.  Notice the key hole mark on it.  So the lowers and the blackthorne uppers where both forged at Cerro.





They look good and seem to be built just as well as my spike tactical lower.  Over all nothing really special to comment on.  They are as they should be.

Now looking into the LPK's I do notice a bit of a difference between the two. First off all of the PSA parts have a layer of oil on them, the Blackthorne parts do not. 



First look at the top of the triggers.



The Blackthorne is on the left, the PSA is on the right.  The machined part on the psa trigger is nice and flat and smooth.  The machined part on the Blackthorne trigger, is not.  It looks like it has a couple grind marks on it and isn't smooth (when I build the other kit I'll check to see if that has the similar marks). Next the hammers are of slightly different design.

Blackthorne Left, PSA Right


The PSA build went really smoothly.  The roll pins went in relatively easily and nothing gave me any real problems.  My only complaint with the build isn't even PSA related.  The PSA kit i bought was their Magpul LPK and I used the moe grip and the enhanced trigger guard on my Spikes lower (which has a RRA 2 stage + LPK installed).  I held off on installing the trigger guard when I originally put together my spikes lower so the RRA trigger guard has never been used.  So I used it in place of the magpul guard in the PSA build.  It installed easily, but it shakes and makes in audible rattle like its slightly to small. Again though its a RRA part not a PSA part. I'm not sure yet what I"m going to do to fix that problem, but if someone has a cheap/free way to stop the raddelling please tell me.  Also I'm not staking the castle nut on either of these builds.  I use blue loctite instead.

The Blackthorne build was smooth....... for the most part.  Everything went in fine and lined up.  The trigger guard went in surprisingly easily. The only big complaint I have, and right now I'm really unhappy with this complaint.  Is the roll pin for the bolt catch.  This thing just wouldn't go in at all even after I got it started. I ended up bending my punch in the process.  At that point in time it was war.  Soooo... the picture below show's the carnage.  Most I mushroomed the head of the pin, but I got a couple nicks on the receiver that a magic marker should fix.  If anyone has any suggestions on how I get it the rest of the way down or something they would greatly be appreciated.  If not, when I go into work I'm going to have our machinist take a look at and see what he can do. Here is the pic of what I'm talking about.



Other than that problem everything went well.  I think I'm going o squeeze the shit out of the pin in the other kit before I attempt to install the bolt catch. I haven't fired the blackthorne rifle yet, but I did do a functions check a couple of times and everything work just fine.  I do want to say the the Blackthorne upper and Aero lower are a near perfect match. Color wise its exact and there is less play between the aero lower and BT upper than with my spikes lower on the BT upper.  Here is a pic of the aero lower and BT upper together, notice the matching keyhole marks.(one is top left other is bottom right)



Here is a pic that shows the upper and lower together a bit better (ie further out)



Lastly here is a pic of the entire rifle all together with the quad rail installed (but nothing on the rail)



So over all impressions (besides the stupid roll pin which I plan on fixing before I shoot it) I'm happy with the first kit so far.  The roughness on the trigger doesn't seem to affect its functioning.  I haven't pulled the triggers of the two enough yet to really tell a difference. I'll play around with all three lower I have together right now and comment on the trigger pulls later.  Now all that is left is shooting it, which won't get done until Thursday or Friday night.

Also, I wanted to add that I borrowed a caliper from work and measured the buffer tube dimensions.  So finally to put this to rest.  The BT buffer tube is indeed a commercial tube and the PSA is milspec. So I got it wrong earlier. I guess the website doesn't even say what the buffer tube is they only thing that comment on is the stock and this is what they say:

"The buttstock is the heavier wall, stronger (1.160" OD) M4 buttstock (not the cheaper carbine buttstock). This buttstock features 6 positions for maximum shooter comfort, reinforced honeycomb design for heavy duty use, and the correct M4 lock nut."

So I guess when I skimmed it earlier I assumed that "the heavier wall, stronger" part had to do with the buffer tube.  So I miss understood it the first time around.

So please comment, ask questions or ask for other pics.  I'm interested to hear what everyone has to say so far.  Also especially comment if you can help me get that roll pin in the rest of the way without breaking anything (I tried channel locks and they didn't budge it, I don't have a vice grips big enough to try that right now with them either).


I just went through and pulled the trigger about ten times on each of the three lowers I have completed right now.

The Blackthorne is the heaviest and the roughest, but surprisingly enough, I didn't get any creep out of it.  When I pulled the trigger it seemed like nothing moved until I hit the pressure that set it off, but for some reason I wouldn't exactly call it crisp.

The PSA was a little lighter, but not much.  The PSA trigger did have a bit of creep though.  When I pulled the trigger it would move a little, at the same time I noticed the hammer would move down a little too, untill I finally reached the pressure that set it off.  I did notice that the action of the hammer was smoother to move and reset than the BT kit.

Finally my RRA NM 2 stage is quite a bit lighter than both of other lowers, the first stage is smooth, and the second stage is very crisp.  Over all I like it better than the other two triggers and its my first NM 2 stage trigger, but I don't know if I like it $69 worth more than the other two.  I guess only after I shoot it a bunch will I decide if it was worth the extra money or not.

Overall each of the lowers behaved as they should, and since the main point of this is to see how the BT rifle turns out I'm happy with the trigger.  I wish it was a bit lighter, but it actioned every time like it should.  I thought I would add the safety's on each of the rifle's work well.  No matter how many times I tried pulling the trigger, or how hard, none of the lowers actioned in the safe position.

[yetisoldier]

Here is the pic of the buffer tube threads.
The top one is the PSA and the bottom one is Blackthorne


Next up some better pictures of the the Primary Arms Quad rail.  These pics should give you a good idea of its quality and how it indexes and mounts to the weapon.

Here is a pic of the top of the rails


Here is a pic of the side that goes into the Delta Ring


Here is a pic of the side that clamps around, what you would normally put the front of the hand guards into.


Here is a view down the inside of the rails from the Delta ring side.  If you notice that indexes to the barrel nut using the bumps machined in to the rail.


I know I did a short description of them earlier, but I'll repeat it a little.  It is a two piece carbine length quad rail.  Four allen screws hold the top to the bottom.  The bottom holes are threaded, so there are no nuts to loose.  None of the screws have thread locker on them, so I would recommend adding some so you don't have to worry about them backing out with vibrations in the future.  They mounted pretty easily.  You install them backwards to a regular hand guards. Meaning you install the deltra ring side first.  Install the top one first, and one you have it in and pushed all the way back into the D ring it will stay on it own. Then install the bottom rail in the same manor.  Once both were in, my screw holes lined up perfectly and I just screwed them down into each other.  I you get the same magpul xtm rail covers I got, wait to install them after the rails are on the rifle.  They get in the way of installing the lower rail.  Here is a pic of on of the rail sections.



They basically attach to each other from each side of the rail so you don't need to slide them over anything.  They are relatively easy to install, but are a GIANT PITA to separate and take off.  The instructions so to use the tip of two bullets and pull up on the locking tabs to separate the halves.  I was unsuccessful removing them with this method.  I ended up just grabbing one side and pulling up with it until the entire unit pulls off. It took a little pulling, but it flexes enough that nothing gets broken or damaged.  You still need to separate the halves to reinstall them, but its slightly easier with them off the rifle.  I know I said otherwise in the first post, but after doing it a couple times, this way is definitely easier.

I haven't shot the upper with the rails installed or mounted an optic on the, but they are rock solid.  I pushed and pulled and tried rotating them by hand and hand no luck at all.  So in that respect I would reserve final judgement until after they've handled the shock of a couple hundred rounds, but they give no indication that it would be a problem.  Also remember that the one rail I have installed right now is indexed slightly off of the receiver.  Its a very slight cant and is close enough it shouldn't make zeroing an optic or laser mounted on it hard.  Its more than adequate for just a light and a pistol grip.  I would say its sturdy enough to mount a sling point to also.  Quality of material wise I would say its on par with the knights armory rails I had (Though I like how the knights armory rails mounted a bit better).  They are aluminum and I don't see any flex or blemishes in them.  If you see any marks in the pictures its from me handling them and banging them around a bit.  Also the rails came with the allen key you need and come with instructions.  The included instructions are crap picture photocopies that are useless.  IMHO if you can't install simple rails like these without a guide, you have larger problems than putting rails on your AR, so I don't really think they need to be included at all.

So overall if your looking for metal drop in Budget rails (with rail covers) for less than $50 to make your AR tacti-cool, look no further.  These ones will work fine and will probably last as long as you own your rifle, unless you decided to go with something more expensive.  These are perfect for beat around AR's and truck guns.  You won't feel to bad if you bang them up a bit. Plus even though they are made in China the company that has them made and imported (Primary Arms) is a great company to deal with has good customer service.

[DeltaOscarCharlie]

...a Plum Crazy lower for $100 and a Del-Ton 16" upper for $379... Them Zombies ain't gonna kill themselves.

Did almost the same but went with a pencil-barrel with a rail gas block.  A $28 rail mount rear sight high profile (gas block rail is low set) rail mount front sight ($18).  Added the Magpul hand-guards.  Had a spare Mako mag well grip that I put on also.  $540 when I was finished.  (I have since added the Magpul BAD and replaced the pistol grip with a Troy Battle Ax CQB Grip [It's small and fits her hand better.  And, I must say, I am starting to like it myself even though I have big hands], rails for the hand-guard, a usable optic [read Trueglow red dot], a Rainier Arms XT Compensator, and a Vltor SASE.) With all that plus the magazines I have about $700 in it now.

This build was for the wife.  She is weight sensitive, finding mine a bit heavy.  Between the pencil-barrel and the composite lower the weight went down to the point she is very comfortable with it.  I too find the trigger crisp on the Plum.  Have put a few hundred rounds through it and it is still very tight and smooth.  We shall see, though.

Cheers.

[DeltaOscarCharlie]

Nice going, YS.  Well put together post(s).  Keep writing and I will keep reading.

[yetisoldier]

Alright the real part of the build finally begins (I'm not posting pics of the whole LPK installation process since that can be found elsewhere).  I'm a little busy, so I only built one of the Blackthorne Lowers, and one with a PSA LPK.  So I have one more Blackthorne kit to put together later.  Here are some pics of the aero precision lower.  Notice the key hole mark on it.  So the lowers and the blackthorne uppers where both forged at Cerro.





They look good and seem to be built just as well as my spike tactical lower.  Over all nothing really special to comment on.  They are as they should be.

Now looking into the LPK's I do notice a bit of a difference between the two. First off all of the PSA parts have a layer of oil on them, the Blackthorne parts do not. 



First look at the top of the triggers.



The Blackthorne is on the left, the PSA is on the right.  The machined part on the psa trigger is nice and flat and smooth.  The machined part on the Blackthorne trigger, is not.  It looks like it has a couple grind marks on it and isn't smooth (when I build the other kit I'll check to see if that has the similar marks). Next the hammers are of slightly different design.

Blackthorne Left, PSA Right


The PSA build went really smoothly.  The roll pins went in relatively easily and nothing gave me any real problems.  My only complaint with the build isn't even PSA related.  The PSA kit i bought was their Magpul LPK and I used the moe grip and the enhanced trigger guard on my Spikes lower (which has a RRA 2 stage + LPK installed).  I held off on installing the trigger guard when I originally put together my spikes lower so the RRA trigger guard has never been used.  So I used it in place of the magpul guard in the PSA build.  It installed easily, but it shakes and makes in audible rattle like its slightly to small. Again though its a RRA part not a PSA part. I'm not sure yet what I"m going to do to fix that problem, but if someone has a cheap/free way to stop the raddelling please tell me.  Also I'm not staking the castle nut on either of these builds.  I use blue loctite instead.

The Blackthorne build was smooth....... for the most part.  Everything went in fine and lined up.  The trigger guard went in surprisingly easily. The only big complaint I have, and right now I'm really unhappy with this complaint.  Is the roll pin for the bolt catch.  This thing just wouldn't go in at all even after I got it started. I ended up bending my punch in the process.  At that point in time it was war.  Soooo... the picture below show's the carnage.  Most I mushroomed the head of the pin, but I got a couple nicks on the receiver that a magic marker should fix.  If anyone has any suggestions on how I get it the rest of the way down or something they would greatly be appreciated.  If not, when I go into work I'm going to have our machinist take a look at and see what he can do. Here is the pic of what I'm talking about.



Other than that problem everything went well.  I think I'm going o squeeze the shit out of the pin in the other kit before I attempt to install the bolt catch. I haven't fired the blackthorne rifle yet, but I did do a functions check a couple of times and everything work just fine.  I do want to say the the Blackthorne upper and Aero lower are a near perfect match. Color wise its exact and there is less play between the aero lower and BT upper than with my spikes lower on the BT upper.  Here is a pic of the aero lower and BT upper together, notice the matching keyhole marks.(one is top left other is bottom right)



Here is a pic that shows the upper and lower together a bit better (ie further out)



Lastly here is a pic of the entire rifle all together with the quad rail installed (but nothing on the rail)



So over all impressions (besides the stupid roll pin which I plan on fixing before I shoot it) I'm happy with the first kit so far.  The roughness on the trigger doesn't seem to affect its functioning.  I haven't pulled the triggers of the two enough yet to really tell a difference. I'll play around with all three lower I have together right now and comment on the trigger pulls later.  Now all that is left is shooting it, which won't get done until Thursday or Friday night.


So please comment, ask questions or ask for other pics.  I'm interested to hear what everyone has to say so far.  Also especially comment if you can help me get that roll pin in the rest of the way without breaking anything (I tried channel locks and they didn't budge it, I don't have a vice grips big enough to try that right now with them either).

Edit:
I got the roll pin in.  A local gun store gave me a pin they had for free and I drove it in from the opposite side.  It pushed out the old one really easily. Also I've come to the conclusion that my punch is what damaged the roll pins.  The end is cone shaped and even started to do the same thing on the new pin.  I ended up using a much bigger one and using its flat side till it was almost in, and then using the one I should for the last little bit.

[yetisoldier]

I just went through and pulled the trigger about ten times on each of the three lowers I have completed right now.

The Blackthorne is the heaviest and the roughest, but surprisingly enough, I didn't get any creep out of it.  When I pulled the trigger it seemed like nothing moved until I hit the pressure that set it off, but for some reason I wouldn't exactly call it crisp.

The PSA was a little lighter, but not much.  The PSA trigger did have a bit of creep though.  When I pulled the trigger it would move a little, at the same time I noticed the hammer would move down a little too, untill I finally reached the pressure that set it off.  I did notice that the action of the hammer was smoother to move and reset than the BT kit.

Finally my RRA NM 2 stage is quite a bit lighter than both of other lowers, the first stage is smooth, and the second stage is very crisp.  Over all I like it better than the other two triggers and its my first NM 2 stage trigger, but I don't know if I like it $69 worth more than the other two.  I guess only after I shoot it a bunch will I decide if it was worth the extra money or not.

Overall each of the lowers behaved as they should, and since the main point of this is to see how the BT rifle turns out I'm happy with the trigger.  I wish it was a bit lighter, but it actioned every time like it should.  I thought I would add the safety's on each of the rifle's work well.  No matter how many times I tried pulling the trigger, or how hard, none of the lowers actioned in the safe position.

[AF275]

This is a great write up. I was curious myself about the PSA lowers. Their prices are pretty damn good.

[Bradbn4]

Thanks for the photo's - now if someone will do a full writeup on building the upper...

I found that Rock River 2 stage triggers to be quite nice, the Double Star triggers felt gritty & vague.  From what I was told the Double Star triggers should have been as good as the Rock River 2 stage  the trigger just might not have been adjusted correctly.

I have looked at Spike's single stage trigger...the coated ones seemed to be the better of the single stage setups.  With the coating they become a lot smoother + are easier to clean if needed.  (Required if you shoot corrosive ammo like Russian 5.45 in your upper).