Question about AR15 being made full auto

The firing pin diameter is related to the relief cut in the bottom of the bolt carrier - easily seen in the excellent photos posted.
The notched top semi auto hammer should snag the firing pin, if it has not engaged the disconnector or sear, and is following the bolt down. Action is jammed with bolt partially open.
FWIW, many years ago, I observed the remains after someone attempted to make an original AR-10 fire auto, without an auto sear. Don't know how it happened, I wasn't there, but both upper and lower were bulged and cracked when the cartridge case failed, firing out of battery.
ATF method was to handload cartidges with soft (even pistol) primers, if they recovered an AR with a M-16 trigger group. The hammer following the bolt would sometimes fire more than one shot, and this could get a conviction, even if the DIAS was missing.
 
JRW (QOR) said:
That's what I thought but wasnt sure.

Thanks everyone, will pass this on as an urban myth.

I guess the fact is none have been seen on the streets, or it would be in the news big time.
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How is it urban myth? The majority of ARs these days ship with FA carriers. Stag, DD, BCM, and even Colt all come with FA carriers these days. So if you put any of those uppers on a FA lower, it will shoot FA.

ETA: If you use an M4 lower then technically speaking you'd get burst fire, you'd need to use an M4A1 lower for FA. While I'm thinking about things, there is a small area that it milled out of the bottom side of an upper, towards the rear. It's there in order to accomodate the extra clearance needed for an auto sear. When Colt made the SP1 they didn't mill out that area so that an auto sear could not be used without modifying the upper.
 
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FWIW, many years ago, I observed the remains after someone attempted to make an original AR-10 fire auto, without an auto sear. Don't know how it happened, I wasn't there, but both upper and lower were bulged and cracked when the cartridge case failed, firing out of battery.
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Since the original AR-10 (not the modern version) was invented before the AR-15, it is possible that it was designed in such a way that it was capable of firing out of battery. I'm not sure though, no one I know is cool enough to own an original AR-10, let alone let me play with it ;)

If anyone wants to show themselves, if you take AR15 carrier out of the upper, extend the bolt (simulating an open bolt), press and hold on the firing pin, and then slowly start pushing the bolt back into the carrier. By the time the firing pin has started to protrude from the bolt face, the bolt has already turned enough to engage the lugs.

Most 'out of battery explosions' are actually case failures and not true out of battery explosions.

Now, if your cam pin is gone, or the firing pin has broken and jammed in the bolt face, all bets are off.
 
Trigger_The_Rookie said:
Full auto requires a full auto BCG (Bolt Carrier Group) and a full auto FCG (Fire Control Group).

If you were to use a SA BCG combined with a FA FCG, it would only function as SA.

If you were to use a FA BCG with a SA FCG, it would only function as a SA.

So.... Yes and no.
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Also requires a lowshelf lower reciever for the full auto selector.
 
Tragedy said:
Also requires a lowshelf lower reciever for the full auto selector.
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Even a low shelf lower requires the area to be milled out further in order for a military auto sear to be used. The low shelf lower exists so that a DIAS (Drop In Auto Sear) can be used.
 
You will also notice that semi lowers from the various makers can have differently shaped pockets to make DIAS installation more challenging. Depth, width, etc.
 
Leg said:
R
ETA: If you use an M4 lower then technically speaking you'd get burst fire, you'd need to use an M4A1 lower for FA. While I'm thinking about things, there is a small area that it milled out of the bottom side of an upper, towards the rear. It's there in order to accomodate the extra clearance needed for an auto sear. When Colt made the SP1 they didn't mill out that area so that an auto sear could not be used without modifying the upper.
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This is what I thought too that even if you put a full auto lower onto a AR-15 upper it won't work full auto unless it has a full auto specific upper receiver with the relief for the auto sear. Bottom line is to shoot full auto you need a full auto gun which the AR-15 is not. It may have common parts with full auto guns but that does not make it capable of firing full auto.
 
andrew3081 said:
You sure know your ar15.
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I was talking about BCG's, and then you go off saying that you need to swap out the FCG in order to make one go full auto. I wasn't talking about making an off the shelf semi-automatic AR-15 go FA simply by swapping out the BCG, so what you said in response to me was unrelated to what I was talking about, and was in fact nonsensical in relation to my post.
 
Yes the AR-15 can be made FA "easily" not select fire just full auto assuming you use the right bolt carrier. Am I going to tell you how, no, am I going to tell you which bolt carrier, no.

Why?

Because the information is out there and not that hard to find, and I figure the same people who aren't able to use google effectively are the same people who are most likely to try the conversion. So why make it easier for someone to half arse a full auto and ruin yet another nice rifle for canadians that is more useful in semi-auto anyways. They already restrict it, why give them a reason to prohibit it.

Remember everything in life is possible with a good imagination and ingenuity. Luckily for gun owners, typical criminals are criminals because they lack both. And the rest of us know that nomatter how fun full auto might be, it isn't worth the jail time, or ruining the publics opinion on gun owners. Personally I don't believe it is worth losing my gun collection to make a rifle full auto, especially one already restricted, what you going to do show off your stupidity at a firing range?
 
Stray03 said:
Yes the AR-15 can be made FA "easily" not select fire just full auto assuming you use the right bolt carrier. Am I going to tell you how, no, am I going to tell you which bolt carrier, no.

Why?

Because the information is out there and not that hard to find, and I figure the same people who aren't able to use google effectively are the same people who are most likely to try the conversion. So why make it easier for someone to half arse a full auto and ruin yet another nice rifle for canadians that is more useful in semi-auto anyways. They already restrict it, why give them a reason to prohibit it.

Remember everything in life is possible with a good imagination and ingenuity. Luckily for gun owners, typical criminals are criminals because they lack both. And the rest of us know that nomatter how fun full auto might be, it isn't worth the jail time, or ruining the publics opinion on gun owners. Personally I don't believe it is worth losing my gun collection to make a rifle full auto, especially one already restricted, what you going to do show off your stupidity at a firing range?
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FA and totally uncontrolled (like a broken sear or jammed firing pin/slamfire) are two different things..
 
Stray03 said:
Yes the AR-15 can be made FA "easily" not select fire just full auto assuming you use the right bolt carrier.
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I have $100 that says you can't make an AR full auto just by putting a different bolt carrier in it. If you can prove me wrong (links to your internet information would suffice) I will give you the $100.
 
I didn't say only replacing bolt carrier and nothing else required, it's not magic. And it is controllable release the trigger and it stops firing. . I can guarantee that I'm not the only person here that knows what I'm talking about. It's easy and tempting to take your money, but unfortunately I will stand by my decision... sorry.
 
Don't be sorry. I simply don't think you know what you are talking about, or else what you are calling "easily" is not what most people would call "easily". I will freely admit that there are people that know more than I do about the functioning of the AR platform, but I have spent large amounts of time researching AR's and read many books on converting them to full auto as well as lots of internet research on the subject. I have never seen a way to "easily" convert an AR to full auto.
 
Uses the same Basic principle as an original m-14's full auto "functions". Anyways I thought there was a rule against discussing in detail how guns are made fully auto on this site?
 
8 ball said:
I have $100 that says you can't make an AR full auto just by putting a different bolt carrier in it. If you can prove me wrong (links to your internet information would suffice) I will give you the $100.
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I'll take the 100$! :D Google "Lightning link".
 
cancer said:
Rule #1 of the Internet: Do not argue with people on the Internet
Rule #2 of the Internet: Do not argue with people on the Internet

Failure to comply with these rules will cause a complete loss of faith in humanity.
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Hmm, sounds like something worthy of debate:D
 
Stray03 said:
Yes the AR-15 can be made FA "easily" not select fire just full auto assuming you use the right bolt carrier. Am I going to tell you how, no, am I going to tell you which bolt carrier, no.

Why?

Because the information is out there and not that hard to find, and I figure the same people who aren't able to use google effectively are the same people who are most likely to try the conversion. So why make it easier for someone to half arse a full auto and ruin yet another nice rifle for canadians that is more useful in semi-auto anyways. They already restrict it, why give them a reason to prohibit it.

Remember everything in life is possible with a good imagination and ingenuity. Luckily for gun owners, typical criminals are criminals because they lack both. And the rest of us know that nomatter how fun full auto might be, it isn't worth the jail time, or ruining the publics opinion on gun owners. Personally I don't believe it is worth losing my gun collection to make a rifle full auto, especially one already restricted, what you going to do show off your stupidity at a firing range?
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Umm no that won't work for a bunch of reasons you wouldn't understand.
 
A select fire selector and disconnector with soft primer ammo will run FA, sort of. Aside from that, you need all the bits to make it run properly.

TDC
 
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