[MarCorpsM4gery]

I don't know about anyone else but as a calming excercise I go through the operation of either a 1911 or M16 in my head in a moment by moment sequence, visualizing every step from loading ammunition into the magazine to the bolt, or slide, locking open upon firing the final round that was in the magazine.

For example: Selector on an M16A2 is turned from Safe to Fire to three round burst, moving the safety shelf on the selector out of the way to free the tail of the trigger to move, then depressing the tail of one of the disconnectors nested in the trigger. Trigger is squeezed, nose of the trigger drops and releases hammer. Hammer strikes firing pin, firing pin strikes primer cup. Primer cup strikes anvil, igniting priming compound... etc...

Well, to get to my point: I thought what about the ACR... the automatic ACR?

My little thought excercise came to a screeching halt. The ACR bolt doesn't have a long tail on the bolt, and it can't, to release the auto sear's hold on the hammer once the bolt was in battery. How would the ACR, using the M16 FCG release the hammer once the bolt was in battery?

The hammer can't ride the bolt for reliability as well as safety reasons.

What are your theories in the ACR auto fire control operation?

Note: This is not an intent to illegally modify my firearm. Simply a mental excercise.

ETA I know I missed a few details but I was begining to feel I was getting to verbose, so I left details out.

 

[cjt50]

Excellent question!!

I have pondered the same thing many times and can only assume that the BCG on the auto version has to be different then what we have. Don't know how though and an i-net search turns up nothing. Someone out there has seen it (JasonAAC) since they had one in house for testing.

Hopefully he will jump in and explain it. (if he can/allowed)

 

[DSM]

I'd imagine instead of the auto sear tab directly above the safety as in the M16, it's moved forward by means of a longer arm w/ a corresponding notch and lug in the bolt carrier to trip it. This way would save tooling set up because an F/A bolt carrier would be the same as a Semi save for the additional machining to allow clearance and for the engagement surface.

Then again, maybe I'm talking out of my ass. I never really thought about it, I wonder if some of the old Masada literature shows anything?

 

[MarCorpsM4gery]

When examining the FCG pack, I noticed the takedown lever has a curved whole to accomodate a pin. I have a feeling that there is a lever that pulls the disconnector away from the disconnector hook of the hammer.

Perhaps it's a lever that activates and deactivates towards the front of the FCG pack?

 

[bigdog2003_99]

look at a g36 f/a bolt vrs a sl8 bolt, the acr bolt is very similar to the sl8 bolt, i think theres a rounded tab on the left side of the acr bolt that allows it to be f/a, if you look in the receiver where the bolt slides and you will see some extended part of the receiver that is blocking the left side of the bolt carrier to have that ramp

http://www.hkparts.net/shop/pc/HK-G36-Bolt-Group-Complete-New-179p635.htm
you can see what i mean on the rear of the carrier, as far as the lower, its probably very similar to a standard m16 except instead of the sear being centered its probably just ran on the outsides of the carrier or on the left

 

[bfelts1ak]

I figured this would be the thread to ask, how do I remove the FCG without breaking anything? Can anyone take pics and post a how to? Thanks in advance

 

[lencomatt]

Its pretty easy, here's a link to a video- http://youtu.be/t8rIJZ08Y4s

 

[bfelts1ak]

Thank you. Didn't even think to Youtube it.

 

[RussTBullet]

I asked a Remington Defense rep at the suppressor shoot. I didn't have a lot of time with so much to do/shoot and not having the entire day. From what I remember he said the f/a sear sits off to one side and is tripped by a lever/arm that lines the receiver.

He wouldn't just let me open it...lol

 

[bigdog2003_99]

sounds simular to the g36 group to me, the sl8 bolt looks exactly like the acr bolt on the bottom

 

[Freedoom]

The BCG is full auto... FA BCG has smaller slot and is more beefy for timing. The slot looks similar to to that of a FA BCG.

 

[Viper5243]

Talked to BM at SHOT about building a postie (Im an 07/02). The guy said i could just call up and they would let me order the parts. Talked to Rem guy and he said BM doesn't have FA parts and he wasn't sure if they would sell them but gave me his card. Waiting to hear back from him on this. Really hoping it comes back positive. Selling my V53 for an ACR.

 

[bfelts1ak]

Talked to BM at SHOT about building a postie (Im an 07/02). The guy said i could just call up and they would let me order the parts. Talked to Rem guy and he said BM doesn't have FA parts and he wasn't sure if they would sell them but gave me his card. Waiting to hear back from him on this. Really hoping it comes back positive. Selling my V53 for an ACR.

Not happening Viper. I called and told em not to sell to you. That is unless you help me get the V2 lower.

 

[Viper5243]

If i could get a V2 lower it would be staying with me. Doubt id get one though.

Im just interested in making it auto. and 5.45