I've noticed on my Arma M15A2 that when I cycle the bolt or hit the bolt release... then eject the chambered round without having fired that there is a small firing pin mark on the primer (not as defined as in a fired cartridge but noticeable).  I understand this is from the inertia of the bolt moving forward.  Just curious.  Is there enough force in the bolt sliding forward to cause an AD or are primer "tough" enough that only the spring loaded push of the firing pin will cause a discharge?  Is this something I should worry about or is it normal?

Thanks
Langadune

The firing pin doesn't have a spring like many other guns. The lack or a spring, causes the firing pin to slide forward from inertia when the bolt is released, putting a dimple in the primer. This is normal and isn't a problem unless the firing pin is damaged, stuck or protrudes too much (a rare situation).

Great thanks!!

BTW, I know there's not a spring on the pin... I meant the spring-loaded force of the hammer

In modern ARs (in working condition) slam fires are nonexistant.

Never seen an AR slam fire, however that muzzle is down range on anything I let the bolt go.

CAN it happen -> YES 99.99% of the time in will not. SOP on a HELO extract or transport was clear chamber, bolt forward, muzzle down. I've heard a few pops when butts were slapped down and the release let go. Good way to get jump wings from a crew chief. Those things went down easy enough without internal help. Just one reason for military primers being hard. Don't worry but remember if your going to chamber a round, the intent is to send THAT round down range, so in turn, point that muzzle down range.

You said it all!

So long as you're using milspec or even most regular ammo the primers are hard enough to be safe but I'd be careful with any match primers that are designed to detonate with a lighter strike.

Cant find the info, but I am sure I read somewhere that troops in Iraq had FTFs due to multiple primer strikes when unloading the round, reloading into the magazine, then chambering the same round but not firing it - repeating the cycle over and over. The primer deformed (dented) so much, when eventually the round was fired, the firing pin could not contact the primer with enough force for ignition.

Was an easy fix, but hell I had never encountered or even considered this. Been meaning to try and replicate this, but have not had the chance. Anyone else experience/hear of this, in Iraq or elsewhere.

Luck
Alac

[url=http://www.ammo-oracle.com/#slamfire]Q. I chambered a round in my AR and then unloaded it later. The primer has a small dent in it,
apparently from the firing pin. Should I be worried about this?  Won't that cause a slam-fire?  Should I switch to a Titanium firing pin?[/url]

This makes me wonder if it is wiser to use AR-15 firing pins in my M16 as the M16 FP has a larger collar presumably making it heavier and possibly more prone (by a small degree) to a slam fire...

Heard of it happening in Afghanistan while I was there.  Just stopped using the same first round all the time.

Oh yeah you're just looking to brag that you have an M16...


[;)]

Normal,  the primers are made with this in mind.  It takes more force then that to get an AD.

I had one but I'm 99% sure it was a primer not seated deep enough, was one of my handloads. Had it pointed up & down range, am much more careful with both safety and primer seating now.

rk

Ah, well, busted on that point.  However, I really have became concerned over the AR-15/M16 pin thing just as of late.  I noticed that a recent carrier assy I bought came with a real M16 pin, and then I realized that I had been using AR-15 pins in F/A all this time, and that many of the M16 carrier assy's I bought did not come with the proper pin.  Bushmaster especially wronged me by putting an AR-15 pin in a M16 assy, and when I bought a separate M16 pin from them, they sent me an AR-15 pin.  Then this got me thinking, do I really need the M16 pin?  I think it's worse than an AR-15 pin due to extra weight reducing lock time and increasing the chance of a slam fire, as well as possibly hanging up when used in semi's without extended carrier ramps.  No one can tell me if they are really more prone to slamfires though.

Sorry to hijack the thread.

I have yet to see a slam fire in a well maintained AR15 or M16....