Armalite LPK (Armalite tactical two-stage trigger set) - Update

I don't remember if I bought this kit for any particular reason other than it was probably on sale and I couldn't resist a good deal.  I did a brief table top review of the kit then tucked the kit away into my spare parts bin for later use.  There are however way better, more in depth reviews of the kit here:

https://www.thetruthaboutguns.com/gear-review-armalite-2-stage-ar-trigger/

https://forum.308ar.com/topic/8135-armalite-2-stage-national-match-trigger-set/

The kit first ended up in my Mk12 Mod 1 Build.  I honestly didn't shoot my Mk12 Mod 1 build beyond test-firing it and shooting a few groups, probably less than 50 rounds of Hornady Steel Match.  There was one time I found a strange piece of metal in the shape of a "D" in the lower receiver, but it was such a strange thing to see and didn't seem to belong anywhere, I set it aside and eventually forgot about it (more on this later).

Eventually, the lower parts kit migrated over to my BCL102 where the kit saw a bit more use (because the 102 was non-restricted, and also because this rifle had so many bugs to work out).

I probably logged about 100 rounds through the 102, but twice at home under dry-fire conditions, I noticed the hammer pin walk out.  I guess I was lucky it didn't happen in the field.  When it happened the first time, I thought maybe it was a one-off.  The second time it happened, I wanted to blame BCL for lack of QC and maybe having enlarged hammer pin holes milled in their lower receivers.  To prevent the pins from walking out again in the BCL, I swapped over some anti-walk pins from another rifle, but while I had the rifle apart, I also decided to yank the Armalite trigger in favor of the Stag unit my buddy had laying around and wasn't using. (see previous post).

The Stag one felt smoother while the Armalite unit still felt a bit on the gritty side.  The Armalite unit also wasn't broken in yet, so the trigger weight was still pretty heavy (apparently it's supposed to settle down to a 5 lb 2nd stage trigger pull).  I measured the new Stag 10 trigger in my BCL and it broke at a nice 4.5lbs:

So now, I had this Armalite Tactical Two-Stage Trigger set laying around and decided that maybe I could use the thing in another rifle.  Which rifle do I have that I sort of shoot sometimes, but has a horrible trigger?  Instantly, I thought of my Bushmaster ACR.

Since I first got my ACR, I had never been completely satisfied with my ACR since I could never find a scope setup that I was really happy with, and part of the reason for that was because of the stupid charging handle, which function was often disrupted by various scope mounts.  For a while, I thought I either had to mount my scope way back, or get a cantilever mount, or get an aftermarket charging handle that sat a bit lower.

As you can see in this photo, the charging handle is angled slightly upwards so it really limited optic mounting choices.

Well, for years, my ACR just sat in my safe, seeing very little use because I just couldn't find the perfect mounting solution.  One night I was bored and snooping around online and discovered I could not only flip the charging handle to the other side (which didn't resolve the scope mount issue), but I could also run the thing inverted so that the handle sits lower.  As soon as I discovered this, my ACR became my new favorite rifle.  I threw my Eotech 512.A65 back on the rifle, along with my 3x magnifier and BUIS....all which I thought I had to ditch because the charging handle always hit the long 512 optic.  I almost sold the Eotech thinking that there was no rifle I wanted to use it on (most of my ARs are clone builds which don't call for this particular model and no, I don't have a Diemaco C8A2 clone).

Compared to the previous pic, you can see the charging handle inverted so it's now angled slightly downward, and completely clearing the Eotech.

Anyway, going off on a tangent here, but long story short, I had a new found interest in my ACR so I figured the thing deserves a better trigger.  Yes, I found the Armalite trigger gritty compared to the factory Stag Arms trigger, and yes, I hadn't even shot the Armalite trigger enough to "break it in" and let the weight settle down to 5 lbs, but it was probably still light years better than the craptastic factory Bushmaster "mil-spec" unit.

Before I yanked the factory Bushmaster unit, I tested the trigger pull and found it to be about 7.5lbs-ish.

I went on YouTube to learn how to take out the ACR trigger pack and it really wasn't that hard once you got into it.

First remove the lower receiver.  Inside the trigger pack there's a tab you have to pull upwards slightly, then flip the selector to the 6 o'clock position.

Flip the lower over and while pulling the same tab upwards, pop the right side of the ambi switch off.  You may need help from a flat-head screwdriver.

Flip it back to the other side and while maintaining upwards pull on the tab, wiggle the selector out.

Once the selector assembly is out, the whole trigger pack comes right out.

The Armalite hammer on the left and the factory Bushmaster ACR hammer on the right.

The Armalite hammer on the left now wearing the ACR hammer spring (the Bushmaster hammer on the right now has the Armalite hammer).  Notice in the ACR hammer spring on the left, there is a slight bend in the right leg.

The reason for the slight bend in the leg is because it sits inside this lever.  

The Armalite trigger on the left and the factory Bushmaster trigger on the right.  I've had the trigger set at the lightest setting (top tab) but since I've hardly used it, it supposedly isn't broken in yet. 

The roll pins which appear to be identical to standard AR15 trigger/hammer pins.  Anyway, I reinstalled everything and tested the Armalite trigger in the ACR:

WTF, 8 lbs???

It sometimes pulled at 7.5lbs but it wasn't always consistent (or maybe the way I was testing the weight with the scale wasn't correct).  Either way it was heavy AF and not any better than the factory Bushmaster unit, in fact, it was heavier.  The only difference was that it was now a two stage unit, and though the Armalite unit was still gritty, it was less gritty than the factory Bushmaster trigger.

  

The next day, I started reading other reviews on the Armalite trigger and read about how the Armalite trigger kit is designed and how the system retains the hammer pin.....suddenly my mind flashed back to this mysterious D-shaped ring I found in the lower receiver of my Mk12 one time.  I had no idea what it was or where it came from at the time and almost threw it out because it looked like the end of a spring, or some bent wire, but the trigger assembly in my Mk12 looked fine and nothing looked broken.  But because it had no business being inside my lower, I set it aside just in case and sort of forgot about it.  

Fast forward a few years and I finally realize what the thing was.  As you can see the little D-shaped metal ring was there when I unboxed the kit:

I thought it may not be an issue with the ACR because the trigger pack sits inside the ACR lower receiver and the hammer pin should be captured by the walls of the receiver, preventing the pin from walking out.

This however proved to be incorrect and as you can see, there is enough of a gap for the the hammer pin to slide out of position.  I tried to remember what I did with the thing and took a look at the state of my work bench:

It doesn't always look like this, however when it is in disarray, it's a complete shit-show.  I've cleaned it and it's gotten messy more times than I can count since I first found the thing in the bottom of my Mk12 lower, but I decided it couldn't hurt to look.

By some miracle however, after sitting on my desk for a few years, I was able to find the ring.  I was surprised I hadn't tucked it away in a zip-lock bag and file it away in my spare parts bin.  I guess I was deciding whether it was significant enough to keep it or toss it.  I think it may have even ended up in the garbage one time, but I must have fished it out just in case I would need it.  

Back onto the hammer it went.

So, now I had to make sure the D-ring stayed on the hammer while I mucked around with the hammer spring leg, the lever, all while trying to get the hammer pin in and past the D-ring.  

The hammer spring leg and where it's supposed to sit as you drop the hammer and lever back into the pack.

After a bit of work, I managed to get it all back together.  The hammer pin snaps into place and the D-ring locks it all in.  It's actually a pretty smart design, however when I first installed it, I didn't even notice it, nor did I read the installation instructions since I'd already done a few LPKs by that point.  I think Armalite should write in big bold words, highlighted in yellow that the installer should pay attention to this.  They should also include a few spare D-rings in case dumb-asses like me lose it.

Anyway, after getting the trigger pack back together, it was just a matter of throwing the thing back into the lower.  

Now my BCL should not have any reliability issues in terms of the charging handle, or the hammer pins, and my ACR now has more optics mounting options, as well as a slightly better trigger (less gritty, and potential to have a lighter pull after break-in.  This trigger better not stay 8 lbs or I'm going to be pissed.  I've been reading about a Tech Note (#14) from Armalite's website about tuning this trigger but most links seem to be dead, but I did find it here.

In the tech note, it says that it takes about 500 rounds of live fire or dry fire for it to break in.  There might be about 50 rounds on the trigger when it was in my Mk12, and about 100 rounds on the trigger from when it was in my BCL.  I guess I'll sit in front of the TV tonight and dry fire it another 350 times.  I wonder if the para-cord trick works in ACRs?

BCL factory 102 Charging Handle - what a POS

I've been using the factory BCL 102 charging handle for handful of range trips and it started to really crap out on me.  Actually, I realized it was crap when I first got it and noticed that BCL staked the charging handle roll pin, something I'd never seen before from any other manufacturer.

My buddy had a spare Stag 10 charging handle he had laying around and gave it to me, so I had a back up in case my charging handle crapped out.

BCL 102 charging handle on the left (with the PRI latch) and the factory Stag 10 charging handle on the right.  You can see the hole for the roll pin is quite large with the BCL unit, and this was not from wear and tear, it was already that big from the factory.  It may have actually been two holes on this side, which is probably why they staked it.  You can clearly see the higher quality of the Stag unit on the right.  One neat, clean hole.

It looks like they drilled the hole a bit too close to the edge of the material.  The Stag unit on the right did not require staking.

Anyway, the charging handle obviously didn't come with the PRI latch, but since I was doing a clone inspired build with my rifle, I swapped out the factory latch with a PRI unit.  When I installed the roll pin back in, it was sketchy at best, lol!

After the last range trip, I was cleaning my rifle and the latch on the charging handle started to come loose.  I wiggled it and the pin fell right out, lol!  

Before I swapped the latch over to the new handle however, I had to fit the charging handle to the BCL upper receiver.  God knows why BCL had to make their charging handle proprietary because Stag managed to get their rifle non-restricted without screwing around with the specs.  With the Stag 10s, you can basically use any large frame AR charging handle.

It took some massaging to get an aftermarket charging handle to fit the BCL upper receiver, but once I removed enough material to get it to fit, I swapped over the latch.

With the Stag 10 charging handle, there was no mess, the pin went in with a bit of resistance (as it should be), and no worry about the pin walking out.  *$%&#@ BCL/NEA, lol!

I also noticed that the hammer pin for the rifle would walk out once in a while....actually twice, during dry-firing while at home.  In my mind, I immediately blamed BCL, thinking they probably drilled the holes too big or something.  Anyway, while I was working on the rifle, I decided to use anti-walk pins from my Mk12 build over to this rifle.  I'd never had pins walk out on any of my other rifles, so I figured I wouldn't need them in my Mk12 (more on this in the next post).

I also had a spare Stag 10 two stage match trigger laying around so I decided to swap out the Armalite Tactical Two-Stage trigger set in favor for the Stag unit.  I found the Stag unit surprisingly smooth for a factory trigger, and the break was clean and crisp.  The Armalite unit, though better than a standard mil-spec trigger, was slightly gritty and had a bit of creep.  I understand these units require a bit of break-in, but I figured since I had the better trigger doing nothing, I may as well use it.

The factory Stag 10 trigger breaks cleanly at 4.5lbs.

Anyway charging handle is sorted and I don't need to worry about it, and it shouldn't have any more issues with the pins walking out.  The rifle should be a bit more reliable.  Now I just have to figure out which mags will feed reliably in my rifle.  It seems that some of the mags that work in my BCL don't work that well in my buddy's BCL, and vice versa.

BCL 102 assembled

So, against my better judgement, I decided to slap the thing together.  I'm still missing a pile of parts, not to mention the barrel nut tool, but I figured I'd just "mock it up"

The barrel nut was tight going on.  At first, I thought maybe the barrel nut had the wrong threads, and I was worring about cross threading the receiver...but I took a chance and spun it a few turns and realized it was just really tight because of the cerakoting.  

I could actually make quite a few turns by hand, but eventually, it got too tight and I had to start using tools....though not the correct ones.  I used a regular AR15 wrench, but was only using one lug insterted into the barrel nut.  But since I was just mocking it up and not really torquing anything down hard, I figured this would be ok.  When the Armalite barrel nut wrench arrives, I will torque it down properly.  

I also improvised using an AR15 receiver block wrapped in cloth and it seemed to clamp down on the receiver just fine.

I actually got the barrel nut on there pretty good.  Thought I was pretty smart until I realized I'd left off the locking ring for the hand guard, lol!

So off came the nut, and back on again.

And that was my uppper slapped together.

Next, I had to tackle the issue of not having any spare lower parts kits.....so decided to butcher my 10.5" shorty with the stripped KAC lower it was assembled using the Armalite Tactical Two Stage Trigger kit, and I would need the trigger for the 102 anyway.  

It was the first time I'd ever stripped a lower of all it's parts.  To be honest, it wasn't that hard.  The only thing I left was the front pivot pin since the 102 has it's own. 

Reinstalling all of the parts was almos second nature at this point, and it was basically exactly the same as any other AR15.

Since the receiver set was cerakoted, and I had experienced tight threads earlier with other sections of the receiver, I was careful to put dabs of CLP wherever I thought friction would be involved, in this case roll pins. 

Trigger guard done.  I was thinking about using an aftermarket "enhanced" trigger guard, but since this was supposed to be some sort of clone of an existing military rifle, I decided to stick with a standard AR trigger guard.  

Next was the left side of the bolt catch, basically where I left off last post.  Since the other side was done, all I needed to do was drop the plunger supplied by BCL.

Next was the spring from the regular AR LPK.

Then the plunger for the bolt catch that came with the LPK.

The last thing to do is lock it all in place using the screw supplied by BCL (all this could have been avoided....read previous post)....and here's where my nightmare began.  I was careful to give dabs of CLP, but it wasn't enough.  because the hole was so tight, I really wasn't sure if I was cross threading the thing or what.  I decided to push through, and the allen wrench slipped.  Fuck.  A few more attempts to turn it, and it just kept on spinning.  

What I didn't realize at first was that it wasn't the receiver that was stripped, it was the screw.  The allen key was made of harder steel than the screws and I ended up stripping the head, not the threads, that's how tight the hole was.  I managed to back the thing out and put it aside.  I backed out the screw I installed on the other side, and started to spin it in on the left side.  It got tight again, so instead of cranking on it, I tightened a bit, then backed out, then tightened, then backed out, sort of like the same thing as cranking on a muzzle device onto a crush washer.  

Anyway, I got the screw all the way in, with no issues, but I still had the semi stripped screw for the ambi side of the bolt catch 

I managed to get the screw in part way into the hole for the ambi side of the bolt catch, but then the screw head was so far gone and stripped that the allen key just kept spinning inside it.  I ended up super gluing the key in the screw and I'd let it sit while I worked on the rest.  

The Armalite trigger dropped right in, using AR15 size pins.  I have heard that lighter AR15 triggers might not have enough mass to move the firing pin on AR 308s, so we'll see if this one will work or not. 

Next was the selector switch and rear take down pin.  Those slipped right in, but BCL/NEA has always been quirky about their rear take down pin detent and spring location.  Instead of using the rear plate, they use the pistol grip to capture the spring.  

So, from the bottom, you have to insert the rear takedown pin detent, then the spring.

Then insert the selector switch detent, then the spring into the grip.  I remember my buddy Alex's selector switch was unusually tight, so I made sure I used plenty of CLP to lube the selector and detent. 

Actually, it really wasn't that hard to install this way.

Next, I had to go back to my fuck up.  That stupid stripped screw.  

I managed to get a few more turns in, and was down to the last 1.5 threads when it just wouldn't turn anymore.

So I taped it all up and took a file to the friggin' thing.  This thing was never coming out anyway, so I started filing.  

I did a pretty good job I'd say, but the ambi side of the mag catch is never coming out.

I slapped the rifle together, though I'll need to finish the thing properly when a few more things come in.  I also have to decide whether I want to take the Krylon to the stock and hand guard.

The selector was way smoother than my pal's.  I'm not sure why, but I'm quite happy with it.

Anyway, that's it for now.  Still need the gas block, gas tube, a different grip that I ordered, as well as the Armalite barrel nut wrench to to torque down the barrel nut properly.