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View Full Version : OLL s going auto?


Mr.RoDiN
03-11-2007, 10:16 PM
I read a few months ago, or maybe even a year ago, some OLL rifles firing in full auto. What is the main reason behind this? How can it be prevented and or tested before going to the range?

EvolutionGSR
03-11-2007, 10:20 PM
I don't remember exactly what was causing it, but I vaguely remember it having to do with either below standard Lower Parts kits, wrongly assembled LPK, or something of those sorts.

To test your own out, just load 2 rounds into the mag and pull the trigger. If they both fire, they're something wrong. Two quick shots going off won't catch too much attention, maybe just a good yelling at by range masters.

MARK1
03-11-2007, 10:27 PM
I think it had to do with those adjustable triggers,...adjusted incorrectly:rolleyes:

PIRATE14
03-11-2007, 10:34 PM
I think a few amateurs, inadvertanly left the disconnector out or over modified it?????

bwiese
03-11-2007, 10:42 PM
I read a few months ago, or maybe even a year ago, some OLL rifles firing in full auto. What is the main reason behind this? How can it be prevented and or tested before going to the range?

Very early into the beginnings of the OLL craze, there were apparently a couple of doofuses popped for their ARs going full auto at the San Leandro range. Apparently the bright boys let things zip while some off duty CHP were nearby - not that Bzzzzzzzzzzrp! pleased range managment, either.

Some poorly maintained ARs with worn or poor quality bottom-feeder parts might double or slam-fire esp with soft-primer ammo. Bad or missing disconnectors can cause this problem too.

Some folks may also be (accidentally?) using M16 fire control parts.

I have never seen an AR double, I've only heard about it. Others' ARs that I've debugged over the years usu had the typical FTE/FTF problems or short-stroking.

Mr.RoDiN
03-11-2007, 10:49 PM
Thanks for the info. But just in case, if I do have any problems with the AR, short strokes and such, are there any gun smiths willing to work on them? Im in the San Fernando Area.

leelaw
03-11-2007, 10:54 PM
If you have an adjustible trigger, make sure you leave enough travel on the disconnector or the recoil can make it bump fire a little too easily.. I've seen it happen, and while entertaining, it's dangerous if you're not expecting it or trained, and if done in the wrong company you can get in some serious sh*t.

Mr.RoDiN
03-11-2007, 11:09 PM
If you have an adjustible trigger, make sure you leave enough travel on the disconnector or the recoil can make it bump fire a little too easily.. I've seen it happen, and while entertaining, it's dangerous if you're not expecting it or trained, and if done in the wrong company you can get in some serious sh*t.

Now if the recoil makes the second shot go off, would this be considered bump firing? Or would it be considered altering the weapon to auto config.?

bwiese
03-11-2007, 11:57 PM
For a variety of reasons - safety, external perception, what the range likes for rate of fire - your gun should require a distinct trigger movement, that requiring adequate force, per shot.

Newbie shooters prob shouldn't have a fancy adjustable trigger.

fun2none
03-12-2007, 12:26 AM
I have observed two ARs fire unexpectedly when the trigger was released. It fired when you pulled the trigger and fired again when the trigger was being reset. This gave the illusion of burst fire.

In the first case it was an out of spec hammer with an incorrect sear angle. In the second case the disconnector spring was too short. Replacing the parts cured the problem.

adamsreeftank
03-12-2007, 2:39 AM
I haven't seen it first hand, but what I have heard is that a common error can lead to a full auto slam fire burst. People accidentally swap the dissconnector spring with one of the other springs in their LPK. The disconnector spring has a flared bottom that seats into the trigger.

I don't think you could "accidentally" create a full auto situation by using M16 parts. Unless you get the auto sear functioning, what we are talking abut is a run-away slam fire. Much more dangerous than true full-auto fire.

Jicko
03-12-2007, 7:06 AM
Basically, if the disconnector/disconnector-spring malfunction and you spam fire.... there is a chance that the hammer may drop before the round is totally chambered.... ie. firing out of battery..... this is extremely dangerous... and potentially your gun can just blow up right in front of you...

The real auto-sear generally holds the hammer, and provides enough delay for the round to completely chamber before dropping the hammer....

6172crew
03-12-2007, 7:09 AM
I haven't seen it first hand, but what I have heard is that a common error can lead to a full auto slam fire burst. People accidentally swap the dissconnector spring with one of the other springs in their LPK. The disconnector spring has a flared bottom that seats into the trigger.

I don't think you could "accidentally" create a full auto situation by using M16 parts. Unless you get the auto sear functioning, what we are talking abut is a run-away slam fire. Much more dangerous than true full-auto fire.

The AR15 will fire multiple rounds if the m16 fire control group is installed, it isnt safe or consistint because the sear is what keeps it safe by not allowing the hammer to go home until the bolt is in battery but it will fire a few rounds until it gets a soft primer hit or it kabooms.:(

capitol
03-12-2007, 7:19 AM
I know several people are complaining the new Timney TG is causing bump fires. The trigger reset is very short and the pull is 3 pounds or less in some Timney TG's.

luvtolean
03-12-2007, 7:58 AM
I've personally witnessed two different ARs double, though I don't know why. Actually the first time I pulled the trigger on an AR, it doubled. Maybe that's why I like them so much. ;)

I was a teenager and not understanding the legal implications, thought it was cool as hell, but the owner got pretty nervous and said we needed to go, despite being out in the middle of the mountains in NorCal.

Anyway, this was back in the mid-90s, and both were homebuilts by inexperienced gun people who probably shouldn't have been playing at home gunsmith. They were more than likely built with bottom feeder parts kits too.

naimad
03-12-2007, 8:08 AM
I know several people are complaining the new Timney TG is causing bump fires. The trigger reset is very short and the pull is 3 pounds or less in some Timney TG's.

Tell your friends to send their triggers back to timney they will fix the trigger some of the early triggers need a little tweaking i had this same problem with mine shooting 2 shot bursts. i sent it back and they fixed it.they are hard to contact just keep trying youll get through sooner or later

Builder
03-12-2007, 8:19 AM
The AR15 will fire multiple rounds if the m16 fire control group is installed,(A properly functioning M16 fire control group should not go full auto without the auto sear. Minus the auto sear and when the hammer follows the bolt carrier home, it will generally not fire because of the firing pin shroud on the M16 bolt carrier. Way back in the early 80's I had an M16 FCG (minus the auto sear) in an AR and in the auto position all that happened was a FTF with the hammer forward. Mil surplus ammo was used.
it isnt safe or consistint because the sear is what keeps it safe by not allowing the hammer to go home until the bolt is in battery but it will fire a few rounds until it gets a soft primer hit or it kabooms.(They say this is true: a soft primer and an AR bolt carrier can do this.
Builder
ps don't worry, all the M16 FCG is long gone.

tgriffin
03-12-2007, 8:56 AM
friend assembled his LPG and forgot about the disconnect spring. First time he shot it, damn thing emptied half the mag at United Sportsmans. Needless to say, he put the thing away QUICKLY. managed to pull out his 10/22 by the time RO made it over. Said he just had the gun worked on and it went full out on him. RO bought it. needless to say, he and I went over the gun very meticulously after that.

Jicko
03-12-2007, 9:12 AM
Perform this "function check" BEFORE you shoot your home-built OLL!!!
http://www.ar15.com/content/guides/functionCheck/