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.