5.56 Timeline

Optic of the Week: ARMS 40 Std A2

Disclosure:  I don’t mean this as a proper review as this was broken and missing parts when I received it.

The ARMS 40 Std A2 rear sight is an older designed BUIS that is spring loaded to flip up and does not lock.  Windage adjustments are .75 MOA.

A few years ago now, I received a disassembled ARMS 40 rear sight.  It was missing the aperture and was reassembled incorrectly.  I had tried contacting them about purchasing the missing parts or sending it in to be rebuild.  If I recalled correctly they never responded to me.

I thought that it would be easy to get an A2 aperture to drop in it and get it operational.  Oh boy was I wrong.

Each time I ordered some part or accessory I needed, I tried to order an A2 aperture to go along with it.  Every time until now the A2 apertures were out of stock.  EVERY TIME!

I even tried to get one from White Oak Armament, they discontinued carrying the standard A2 rear sight aperture.  WTF?  I guess A2 sights are truly dead.

Finally I made an order from MidwayUSA and they had only had a couple DPMS A2 apertures left.  So I got one.

That aperture installed just like how you would install one into a carry handle.  Now I am able to use the sight.

To install one of the ARMS 40 series sights, you unscrew a nut.  This nut has a wide slot on it so that you can use a screw to remove it.  It is suppose to be secured with a wire tether to the sight, but this old abused sight lacks that.  The base of the sight is slid onto the rail, the cross bolt inserted and then locked in place with the nut.


On the right rear of the sight is the latch that securely holds the sight down.  It is quick and easy to release the sight and the sight springs up.  You can also easily secure the sight down one handed.

The sight springs up.  It is suppose to lean slightly backwards so that if the weapon is dropped the sight folds.  It does not lock with the intent to hold to prevent damage.  Mine seems to lean a little forward.  Letting it spring up on its own makes noise, but I wouldn’t call it loud.

The sight is notched so that if it is pushed down it has clearance for the latch so that nothing is damaged.

With the A2 aperture this sight provides the same sight picture of any other A2 sight.  The first ARMS 40 models had a cut down peep to make the sight shorter.  They also offer the ARMS 40 STD A2 that has a standard A2 aperture like this one.

I had initially intended to fix this sight and then sell it.  But I think I found a home for it.

I remember a short time back in the day when flat top uppers were first getting popular that the ARMS 40 was considered the best BUIS out there.  But that quickly changed.  MSRP is $136, so there are cheaper excellent options.  The tall height of this sight prevented many optics from fitting over it.  I found I couldn’t put an ACOG or several of my standard scopes over this BUIS when it was mounted to an AR15.  ARMS later made the ARMS40L a low profile version of this sight.

I’d still love to have one of the low profile ARMS 40L-P models, but I’m not going to spend the cash for one.

This was a good rear sight, but when options like the Troy flip up sights came out, these seemed to be quickly forgotten.  Locking sights were perceived as being more durable.  Not to mention many of the good alternatives were cheaper.

Now, the ARMS 40 series is an expensive obsolete relic.

Optic of the week: HK Diopter BUIS

Ok, I’m phoning it in this week.  I found these old HK BUIS I thought I sold long ago, and I found that the old article on them has all the images missing.

On the HK416/MR556 and their .308 rifles as well the optics rail is higher than the rail on a standard flat top AR15.  Because of this HK fixed iron sights are lower than standard height AR15 sights so they can not compatible to use together.  Not that you would want too.

Under the 200m aperture of the drum, there will be 1 or 2 dots.  If there is a single dot (like this one) the sight is calibrated for a 10.4 inch barrel.  If there are 2 dots, it is the model for the 14.5 and 16.5 inch barrels.

HK Front sights are not adjustable, all zeroing adjustment is done on the rear sight.

The drum apertures are different sizes and set for 100 to 400 meters.  The 100m opening is much larger than the other ones to make it easier to use for close quarters use.

Windage is adjusted by loosing the screw on the top of the sight, and turning the screw on the right side of the sight.  1 full turn will move your point of impact 6 inches at 100m.  Tighten the top screw to lock the sight back in place.

Inside the drum there are two tabs.  Compressing both tabs inwards allows for the drum to turn adjusting the elevation of the rear sight.  You need to turn the elevation drum in 1/4 turn increments for 1.5 inch adjustment at 100m.  If you don’t have the proper sight adjustment tool, you can make adjustments using a pair of needle nose pliers.

Zeroing these sights can be annoying.

They are nice sights, and if you are more familiar with HK style sights than AR sights, it is nice to have this option.  However you can get good AR sights for cheaper that will have a finer and easier adjustments.

Looks like the barrel is shot on my favorite AR.

My favorite gun started key-holing last weekend.  It is the most distraught I’ve felt in a long time.  Like losing an old friend.  Extra kick in the nuts was that I just rebuilt the gun as I was upgrading it.

After I had issues with my first SBR I decided I’d have another built no holds barred.

I started seeing pictures of 10.5 inched barreled carbines with the 9.5 inch long Daniel Defense Lite rail.  I really liked that setup.  That rail was a predecessor to the RIS II rail.  Similar profile but the bottom rail was lower and did not detach.  I was planning to use one of those when I learned about the RIS II rails.  I liked the idea of being able to remove the bottom rail for cleaning.  And one of the Daniel Defense reps told me that ALL the RIS II rails could mount a M203.  Later I learned that was not true of their MK18 Rail.

I like this upper setup so much I decided I’d swap the old WOA upper on it with a Colt FDE upper and have one of my SBR lowers Cerakoted Burned Bronze to turn this setup all FDE.

Sort of like that, but with an FDE lower.

It was interesting pulling this old upper apart to rebuild it.  There was a little corrosion:

Along with lots of gunk.

But everything cleaned up nicely:

The barrel was part of a limited run from a company that no longer exists.  They had Douglas blanks turned down by Compass Lake Engineering with wylde chambers.  Then a small part of this batch was given an ion bond finish.

Now days I wouldn’t recommend a match barrel on a SBR.  But it sure was a fun combination.  I don’t know how many rounds I had through it, but it is somewhere around 10,000 +- 3,000.  Match ammo, m193, m855, lots of wolf and other assorted cheap ammo, some of it fired full auto on other peoples lowers, lots of rapid fire.  Only failures I had were two case head separations with Black Hills blue box remanufactured ammo.

I often drove my self nuts trying to shoot very small groups with that 75 grain boat tail open tip match Black Hills ammo.  I would shoot 5 or 10 round groups and have 3 or 8 rounds touching under half an inch at 100 yards.  Then always I would have a shot or two that opened the group up to 1.1 inches.  Drove me mad.  Later I was told by some other shooters that used the same ammo that about 1.1 inch groups at 100 yards were what they normally got out of that ammo.

For a long time this was my main AR.  It also functioned as a test bed.  If I had something new to test, try it on with this gun.  Note, I have multiple SBR lowers and I move uppers between them.  In no particular order here are a few of the setups I’ve used other the years and happened to take photos of.

I hated the UBR stock, but when I had one, it was on this rifle.

I even ran an A1 fixed stock on it for a while after I got rid of the UBR.

I’ve used many different iron sights and scopes on it.  I used Troy BUIS for a long time before finally deciding that I liked the sight picture of the KAC sights the best.

That picture is from when I was joking on a forum about having an offset ACOG for close in work when you are running your fixed 10x scope.  The ACOG was mounted to an offset rail which at the time I was normally using a Doctor sight on.

Yup, I even had an ACOG with piggyback T-1 back in the day.  I love the combo of running the Nightforce 2.5-10×24 on this rifle as the rifle is accurate and the scope makes hitting what you want to hit easy.  I sent a good number of round downrange at 565 yard targets with a Nightforce on this upper.

In the past I’ve called this gun my “Micro-Recce”.  A rifle small and handle enough for fast work, but plenty accurate enough if you needed to take a little longer shot.  But in hind sight I think everything practical that I ever did with this rifle could have been done just as well with a chrome lined barrel.  Had I started with a chromed barrel I probably wouldn’t be rebararreling it now.  While a well made stainless barrel will hold  up to a great deal, it just is not made for sustained abuse.

I’ve tried a great number of fun or odd setups with this gun.

I was debating if it was time to retire this upper and build something different but instead I decided that I am going to rebarrel it.  I’m taking a Colt M4A1 SOCOM barrel that I have lightly used and having it cut down to 10.3 inches by ADCO Firearms.  The old 4 slot Legacy Surefire mount is going to be replaced with a new Warcomp.  I know a collector who is going to give that 4 slot a good new home.  This new set up should give me a good reliable accurate barrel (but not a match barrel, which I feel is excessive on a SBR).  The Warcomp will reduce the already minor recoil.  That will give a great deal more life out of this gun.

I’m relieved to know that I am going to still be using this years to come.

Review: Chaos Ready Flip Up Iron Sights

I was supplied a set of Chaos Ready Flip Up sights to try and review.  When I saw that they were $27.99 I was pretty doubtful on the quality of them.   When the average back up iron sight set costs about $200, I was really curious what $28 would get.

I was surprised.

These sights are sold on Amazon, so you get the normal Amazon fast shipping.  Each sight is packaged in a small ziplock bag inside the box.  The packaging also included an Allen wrench for installation and instructions.  The little box they were in was falling apart when I received it.


When I first looked at them I was pretty impressed as they were far nicer than the cheapest BUIS I’ve seen before.  Sometimes you see knockoff BUIS which are copies of major brands and they just feel cheap and chintzy.  These seemed decent.  There is a subdued logo on the front of each sight.

These sights lock in both the up and down positions.  Pressing the button on the left side lets the spring on each sight pop it up into the deployed position.  Like most BUIS, there is a little play in them when they are in the deployed position but the spring keeps the sight consistently in the same place.

If you have used A2 sights, you will be familiar with the adjustment and use of these.

Front sight is just like an A2 front sight except the detent holding it from turning is on the left.  Adjustment is easy.  I haven’t checked if the posts are interchangeable with standard front sight posts.


The rear sight is low profile but it has the rear aperture sticking up.  That may interfere with some optics.


So what are the downsides of this $28 dollar sight set?

The biggest one on this one the detent for the rear sight windage adjustment is not very positive.  It takes almost no force to turn that windage knob and I am concerned that the slightest bump or aggressive flipping between the two apertures would change the zero.  I don’t know if all the Chaos Ready rear sights have this issue, or just mine.  I see this as potentially a big issue.

There are two lesser issues.  A minor one is that because the buttons to flip up the sights are on the left side, if  you are a left handed shooter shooting from the left shoulder it may be a little awkward to deploy them with your right hand.  Practice would negate that.

The other minor issue involves the space between the charging handle and the rear sight.  Between the button and the body of the sight and the charging handle that area is getting kinda crowded.  If you are going for maximum speed in weapon manipulation you will probably want an extended charging handle and perhaps move this rear sight up a notch or two.

I really like this front sight, and I love being able to push a button and have it snap up into place.  The loose windage adjustment on the rear sight makes me less than thrilled about the rear sight.  If they sort that out I would probably highly recommend these.  I could see my self buying more of these just for the front sight.

They don’t compare to the $200+ competition, but at $28, I am very impressed.  The real question is going to be how well they hold up over time.  I am looking forward to finding out.

Rant – Selling to Gun People & Former Military

One of the good things about gun nuts is that they are more likely to be honest people. Not that there are not plenty of scumbags out there, but a slightly less percentage of those are gun nuts.


I swear, some times I really hate trying to sell stuff to gun nuts and former military as they can be the cheapest bastards out there.

I was trying to sell some old uniform items and this military officer kept trying to play games to get me to give him a discount. Finally when I wouldn’t and told him that I wasn’t going to sell to him then he tries to come in with false sympathy because he is all worried that I am suicidal.

WTF dude, not wanting to deal with an asshole doesn’t mean that I am suicidal.


Gun nuts can be ridiculous in trying to get a deal. I know, I done similar.

I can’t begin to tell you how many times I was selling a light, BUIS, bipod, or something and had it pictured on a rifle in the ad.
It never fails, I would get some comment like:
“You know that thing you are selling for $200, I’ll offer you $100 if you throw in the rifle too.”

No buddy, I’m not going to sell it for half price and throw in a rifle for free.


One time I was trying to sell some stuff, then I had a few surprise medical bills. I added to my advertisements that I had some medical bills and I would appreciate a fast sale.

Oh that was a mistake. Jerks came out of the woodwork offering me 10% or less of my asking price. When I turned them down they started acting like they were debt collectors threatening me that I wouldn’t be able to pay my medical bills otherwise.

No asshole, I’m not going to sell you a $1000 gun for $100.

So I paid my medical bills out of my emergency funds, removed that comment on the ads of the items I was selling and sold them all with in a month or so at the asking price.


There was a hard to find AK part I was selling for $100.  Someone contacts me and offers me $50.  I tell him that I would be willing to do $75.  He then says that he can’t do $50, but would be willing to do $35.

I got so annoyed I relisted it for $150.  I sold it the next day at $150.

Continuing on that note, there have been a few times when I was negotiating a price with someone when someone else offered me my asking price.  So the new guy with the cash gets it.

Once I had the person, who was haggling with, threaten me for breach of contract, even though we never agreed on a price.

Time you spend haggling is time someone else might be using to buy it.


I’m sure we all share the dream of going to some garage sale and giving an old staving widow $20 and a can of cat food for a crate of Singer M1911A1 pistols. But lets try not to be an asshole when we try to rip people off for that killer deal.