AR Top Charging "Trigger" Mechanism

[holdencm9]

I am just super interested in design and the evolution of the AR design. I saw this photo of a top-charging AR and it fascinated me. Does anyone know how things progressed from this top-charger to the eventual charging handle we know today? Did it have something to do with mounting optics and the eventual progression to flat-top designs? Or was it something else entirely?

Did this top charger cycle with the bolt, or does it just stay put, like today's charging handle? If it cycled, I can imagine a forward assist is unnecessary, as I have read that the FA did not exist on the original AR design.

Is there a definitive historical text about the AR? Just curious. Sorry for the nonstop questions, but I figure THR is the place for awesome historical knowledge.

Does anyone HAVE one of these things? Pics appreciated!!!

Thanks everyone,

 

[Dr.Zubrato]

Interesting question! it doesn't look to be reciprocating based on the cutout on the underside giving enough room for free and separate rearward travel of the BCG, and it looks like when its charged, the rear end exits the upper receiver. I dont see any retaining mechanism for the charging handle, and I dont see any ears on the charging to ride in its own rail, as in the modern design.
It looks awkward to use, and I do think the T handle is a huge improvement, especially the BCM gunfighter charging handle.

I dont remember the reason for the evolution but I read somewhere it was an army modification along with the FA.

People hate on the FA, but I find it really useful to chamber rounds more quietly than slamming the bolt carrier home. BUT, id never use it to cram a round that doesnt want to feed into the chamber.

Definitely sticking around for someone who knows their AR history! Cool thread.
Do you have any other internal pictures of the very early AR models?

 

[crazysccrmd]

I don't know the right answer, but I'd venture to say that it was changed from an ergonomics point of view. Think about how hard it would be for a big ham handed dude wearing cold weather gloves to get in there and charge the weapon.

 

[Sam1911]

NODAKSPUD makes the parts if you want one.

http://www.nodakspud.com/AR Lowers.htm

Scroll about 1/2 way down the page. Lots of very retro, first-period type AR-15 stuff there.

 

[Destructo6]

James Sullivan, the guy who adapted the AR10 mechanism to the AR15 (designed the Mini14 and Ultimax, among others), said that the upside down trigger setup of the AR10 became extremely hot, when used in the .223 Ar15. Closing the open slot on the top of the receiver also made it quite a bit stronger.

So, he came up with the long 'T' style charging handle that we know and love.

There was a great article in Small Arms Review from a few years ago that interviewed L. James Sullivan. I believe it's reprinted on AR15.com.

 

[wally]

So, he came up with the long 'T' style charging handle that we know and love.

Good thing or the AR would be as tough to mount optics on as an AK is.

 

[Grunt]

Yup, the original AR-10 used this style of charging handle and I want to say that one of the first prototype AR-15s (might have been number 1 or 2) used this same design. With production Ar-15s though, the small triangle charging handle came out with the introduction of the 601 which later evolved into the more familiar T-style we know today.
As far as reference material on the development of the M-16 family of rifles, you MUST HAVE the book, "The Black Rifle M16 Retrospective" by Blake Stevens is what you need.

 

[Willie Sutton]

^^ What he said.

I own an original ArmAlite AR-10 (Dutch manufactured, Portuguese Contract) and it uses the original under-handle cocking system. It does not reciprocate. It's actually pushed down slightly to unlock it from it's forward locking slot, and then pulled back. If the bolt is held back (manually using bolt stop or by empty magazine) the handle can be pushed forward to lock it, exactly like the more modern charging handle. There are sheet metal sliding shutters to prevent dirt, sand, etc., from falling into the action.

IHMO, this is one of the defining features of a "real" AR-10, and I don't use the term to describe any other 7.62mm AR varients. Then again, the "real" ArmaLite (and yes that's spelled correctly) was a division of the Fairchild Engine & Aircraft Company in Costa Mesa California, employed Gene Stoner, and has been out of business for years. The present company using the name isn't any more "ArmaLite" than their 7.62mm AR-15's are AR-10's.


Willie

.

 

[holdencm9]

Wow lots of great info here guys, thanks!

I am always interested in the evolution of design. It is amazing how many iterations of the AR exist. Sometimes we take it for granted!

Here is another photo I found in my googling. Two things stand out immediately:

1 - I never knew the AR started with the gas tube on the side.
2 - I never knew the buffer and bolt carrier started as one solid piece. Apparently to disassemble the upper and lower it had to slide apart, rather than just being able to remove the rear takedown pin and swiveling the upper up to gain access to the BCG and stuff. I definitely like the new way better though!

Grunt...that book does look like an awesome resource...unfortunately on amazon it sells for $100 let me know if you know of a cheaper source.

Sam, that website is awesome. I am not ready to plop down money for a retro AR 10 quite yet, but glad to know they are available!

 

[HammsBeer]

As much as I like shooting the AR platform, it always puzzled me why they designed it to need two hands to lock the bolt back. I have no issues with reciprocating charging handles on any other rifle, why not have a fixed handle on the AR?

 

[HHollow]

There were two major styles of charging handles amonge the early AR10's.
The Cuban, Guatemalan, Sudanese, and Transitional AR10's all had pretty
much the same CH (shown in the OP). It did get pretty hot on sustained fire
and the LMG and belt fed versions of these rifles tended to have a modified
CH where a portion was made wiht bakelite so as to reduce the chance of
burned fingers. So up to about SN 004500 the CH was a one-piece affair
that retracted over the buttstock.

Next came the Portuguese contract AR10 which has an more complicated CH
that did not retract over the buttstock and also could be used as a forward
assist. The Porto CH is shown below on a scoped rifle. You can see that the
Dutch figured out how the trgger CH could be compatible with a scoped carry
handle. A very nice photo is linked here that shows the Porto CH parts.


The Dutch also experimented with many different prototype charging handles.
My favorite is below, where a lever is pulled from the side of the carry handle.
The lever could be changed to pull from the left or the right. An upper receiver
from one of these proptotypes actually sold on ar15.com just a few months ago
and I was the lucky buyer.


A more modern CH style was also tried that begins to resemble was you see on
todays AR's.


There are also a few Dutch AR10 prototypes that have a CH nearly identical
to the present version. On this one you can still see the stub were the old
handle was milled off.


There were also a few versions made with a reciprocating CH. The complicated
part is how they figured out how the removable knob should be attached.

 

[barnbwt]

Top charging SMGs were huge at the time (UZIs). I don't know if the FAMAS was around at that time yet, but it also has a CH with a similar layout (but a larger sight rail)

To think I'd come up with something original with my foregrip CH concept . There are no new ideas

TCB

 

[7.62 Nato]

I would like the ARs a lot better if they had a side mounted charging handle more like the FALs.

 

[barnbwt]

As a minor, minor thread jack related to the AR's development; why did they go with a mechanical forward assist instead of knurling or cutting a notch into the bolt for a finger to press the thing forward? They functionally ended up making two non-recip handles opposed to each other with the current setup, when pushing the bolt carrier into battery worked fine for the G3 series of rifles (granted that bolt design allows for a deeper thumb notch than the tubular AR bolt carrier, but knurling like that used for the actual forward assist is more than sufficient for a thumb to slide the assembly the rest of the way into battery.)

TCB

 

[chicharrones]

Nice pics and info, HHollow.

 

[holdencm9]

barnbwt, I do not know for sure but I have read that the FA was added after the fact, because it was requested by the gov't. The AR bolt carrier does have a recess where you can use your thumb to push it into battery (it is also the recess that the ejection port cover rides in. But I imagine two problems. One is it may get super hot. And 2 is that if you are wearing gloves and/or just have very large hands, it might be difficult to squeeze a finger through the ejection port to push the bolt into battery. Something that may have never been a problem on the original AR10 (larger cartridge, larger ejection port, easier to push the carrier). So I would surmise that is the reason for adding the FA after the fact.

HHollow, thanks for the info and awesome photos! Maybe we can turn this thread into one big collection of retro AR pics.

 

[Destructo6]

Funny how things were modified or designed 50+ years ago lent the AR to incredible flexibility.

Case in point: no T-handle charging handle = no flattop.

 

[theotherwaldo]

Copies of The Black Rifle M16 Retrospective are running from $50 to $75 on Ebay.

 

[Willie Sutton]

"why did they go with a mechanical forward assist instead of knurling or cutting a notch into the bolt for a finger to press the thing forward?"


Because there were too many cases of letters reaching congressmen from parents of dead soldiers and from soldiers themselves about M-16 unreliability in Vietnam. After many investigations and finger-pointing, it was attributed in the end to a change in the powder used, from IMR (Improved Military Rifle) to Ball Powder in the cartridges that badly fouled the actions. Congress saying "Do something DAMMIT and do it NOW!!" led to the forward assist.

In the literal heat of battle, the Forward Assist is a lot easier to bang on when there's a Gomer aiming an AK at you as you try to clear your jammed M-16 than is using your thumb thru the ejection port.


Willie

.

 

[4thPointOfContact]

Why didn't they go with a dished/notched area on the bolt carrier instead of a separate forward assist?"

D'jever put you fingers on a firearm bolt after being in a firefight and going through enough magazines of ammo to make it jam?

 

[horsemen61]

Great informative thread

 

[sawcut]

Wow HHollow, thanks for posting that information and photos of the early ArmaLites.

It is certainly true that the side benefit of relocating the charging handle from the top of the receiver opened up all benefits of putting the integral picatinny rail on the top of the rifle. The simple mounting of optics or irons on the top rail is a pretty significant feature.

Your photos also show that many ideas have come up before - such as the side charging handle, with the ejection port opened up accordingly. Great information and pictures.

 

[itsa pain]

I don't know the right answer, but I'd venture to say that it was changed from an ergonomics point of view. Think about how hard it would be for a big ham handed dude wearing cold weather gloves to get in there and charge the weapon.

How would the ham fisted guy charge an AR with the standard charging handle with gloves on?? I remember the original AR 10 in 308 had that upper charging handle

 

[Justin]

I would like the ARs a lot better if they had a side mounted charging handle more like the FALs.

JP makes several variants of AR10 and AR15 rifles that have a non-reciprocating side charging handle.

I've shot them, and they're very nice. However, I've found that a side-charging handle not only doesn't fall under "necessary" for the AR, it's just barely in the category of "nice to have."

Ok, as someone who would have agreed with you at one point, let me explain:

The main claimed advantage to a side-mounted charging handle is that you can execute a reload of the weapon without having to bring it down from your shoulder, thus allowing you to keep the gun on target as you reload.

However, the thing with the AR is that you're very unlikely to need to run the charging handle in a quote-unquote "tactical" situation.

The only time you'll run the charging handle is when you're taking the gun out of storage for the first time. After you run the charging handle the first time, you're unlikely to ever touch it in normal operation.

Generally, if you're shooting "tactically," you'll be reloading the rifle before you run it completely dry. Dumping a partial magazine and putting a new one in doesn't require you to run the charging handle, only to activate the magazine release.

Ok, but what if you do run the rifle completely empty?

In that case, you dump the empty magazine, stick a fresh one in, and hit the bolt release paddle on the left side of the rifle.

The bottom line is that the charging handle is the least used interface feature on the AR, and you're unlikely to ever need to use the charging handle in a situation where having the gun up and on target is advantageous.