Obviously the usual method for storing or transporting a carbine is with the bolt down on an empty chamber, but out of curiousity, how drop-safe is the weapon with a round in the chamber, selector on “SAFE”?
I realize that with a floating firing pin, dropping a safed carbine out a third-story window onto the muzzle might set off a chambered round via firing pin inertia, but on the other hand the design/specs must have envisioned preventing AD’s in the course of ordinary falls, drops, and impacts. Is there any way that dropping a Condition 1 weapon 4 or 5 feet onto a hard surface would release the sear, or is the safety system pretty robust?
Civilian HD use and 3-gun/USPSA type stuff involve moving with a Condition 1 weapon (as does plenty of LEO/*.mil use, obviously), so it’s not an entirely abstract question.
5.56 has hard primers. When you close the bolt, the pin actually hits and can indent the primer, but that isn’t enough to fire it. I think the only thing that can set it off on accident is baking the round in an overheated chamber. But I’ve never dropped mine, so…
I’m mainly wondering about the security of the safety mechanism/trigger group itself, i.e. is there any conceivable way that an impact could jar the mechanism enough to trip the sear/drop the hammer, which would indeed fire the chambered round. I suspect that mechanism is pretty robust, though, given that I’ve never heard of any dropped-rifle-fired incidents, but I was wondering if there was any specific design criteria for that.
I’m going to go ahead and say absolutely. It’s mechanical, and with all things mechanical, I’m positive that if it’s knocked in just the right way or if a critical component is worn-down just enough, you’ll get an AD.
It’s conceivable, but my guess is it’s probably pretty tough. Might take a 3-story drop, might take a strong bump from just the right angle. I’ve got no experience as to where that line is, though.
True, any mechanical device can fail via worn parts or faulty parts, but I’ve never heard of it. As the days pass we’ll see if anyone here has heard of it - surely there are a few instances somplace. However I think if it was common we’d definitely hear of this especially in discussion forums such as this with folks who have enormous experience with these guns. I’ve not seen this issue come up here or other places so it must be rare. The abuse military rifles take would surely expose it if the sear/trigger system was susceptible to this sort of thing.
Don’t forget that not all AR15s are made equal. Mil-spec isn’t the be-all, end-all standard of quality, but it’s a more rigorous standard than some bottom-of-the-barrel ARs, I have to imagine.
i once fell from about 10 feet high, off of a substandard, iraqi-built, brick wall and the m16 i had didnt fire off the round. thats about the only experience i have with dropping a rifle. i took the sling off me so i could climb up on the wall and onto the roof and the damned bricks came off the wall in my hands. it was kinda funny after i got my wind back.
In theory, the AR is NOT drop safe at all. There is nothing to stop the firing pin from striking the primer if the hammer were to let go in the event of a mechanical failure or impact that jarred the hammer free.
Practically? I don’t know. But I generally don’t leave a live round in the chamber unless I’m holding the weapon in my hands.
the safety is a bar of steel that physically prevents the trigger from moving far enough to lose sear contact with the hammer… the only way the hammer can drop on a safetied AR is if one or both sears sheer off, the trigger pin sheer off, the safety bar on the trigger breaks off, or if the safety itself is removed (i doubt even a cracked safety, so long as it’s still in place, would allow enough movement).
i’ve done quite a bit of trigger experimentation. i’ve made some of the most beautifully smooth, short, crisp triggers you could imagine, without reducing spring tension (and therefor not reducing strike reliability)… but the point of diminishing return is an EXTREMELY fine line. in drop testing, i had FCGs that would drop the hammer from a 6" fall to the buttstock. but NONE would ever drop hammer when on safe.
Failure2Stop, rrpederson, bkb0000, that’s exactly the kind of information I was looking for, thanks. So it looks like the safety system is pretty darn robust, and barring catastrophic failure of some major parts, dropping a safed carbine from any reasonable height won’t drop the hammer. That’s reassuring.
Armati, do you know what the criteria are for the M16/M4 system? I’ve seen some of the criteria for pistol drop-safety tests around the 'net, but have never noticed any for issue rifles.
I had an AD in BCT running 2 man fire and manuevers. Weapon on safe, knees down, buttstock down, kaboom. I was pushing awhile for that one until my Drill Sgt could find a blank and it did it again. To this day I wonder why that happened and it’s a good thing we had those long ass A2s, with an M4 and a collapse stock I could’ve took it in the chin w/ imperfect form :eek:
you couldn’t butt-stroke someone hard enough to cause a slam-fire… the weapon cycles WAY faster/harder than you could ever induce my mortaring it on someone’s face.
however, the risk of a hammer dropping if the weapon wasn’t on safe is definitely there- i remember being concerned about that during bayonet drills. now that i’m older/wiser/much more experienced with the platform, i wouldn’t hesitate to butt-stroke if i somehow found myself in a situation where the weapon is still loaded, on safe and, for some reason, im needing to buttstroke someone. i can’t imagine a situation where the stars would align like that, but there it is.
I see anecdotal accounts on both sides of the issue. I believe what each person has posted. But until I saw some thorough study on the matter, I would NOT consider the AR a drop safe weapon.
The AR is not designed as “drop safe” but I have it on very good authority that it would take a fall from about a seven story building to get it to go off. Apparently, if it lands exactly straight on the muzzle, it might go off from a three story drop.
I doubt we will ever see a study because one is not needed, at least with the military. If there was an issue, it probably would have manifested itself, especially during the last six years.
My own personal study (experience) tells me not to be concerned about it and that it is not a consideration for keeping the weapon loaded.
