This doesn't seem safe

[riverratt]

I have an Eagle 15 that I've ran maybe 500 or so rounds out of with no issue at all. I just started reloading some of my collected brass and wile checking some of my reloads for final fit. This was after I made my dummy round and checked it. I noticed that the ejected live rounds have a mark on the primer where the firing pin had contacted them. I then checked a factory round, same thing. I'm assuming this is from the forward momentum of the bolt slamming forward when it chambers the round.

I have contacted the manufacturer and they stated that it was normal for that to happen. It seems like I read something on here about this happening but I can't find it or remember what was said. So I'll ask is it normal?

[DubC-Hicks]

Yup. AR's have a free floating firing pin that'll move forward against the primer when the bolt slams home. Happens on every AR I've had.

[turtlehead]

Yep.

[riverratt]

Got it thanks

[marine6680]

Normal for an AR or any rifle with a free floating firing pin.

Its rare, but a slam fire can happen due to this. Usually the primer is just unusually sensitive.


I have only ever heard a few second, third, fourth hand accounts of it though.

[Mobuck]

If you're concerned about this, use CCI #41 primers or get a titanium firing pin.

[Sevens]

Yes, it's normal and no, I truly do not like it either and it seems like a legitimate safety concern to me also but the sheer number of AR's on the planet appear to "prove" that it's not a large concern, but it is STILL a firing pin leaving physical evidence that it is bouncing off a primer.

One of the best ways to combat a catastrophe is to only ever chamber a round from a magazine which is really the proper way to treat absolutely any semi-auto firearm anyway, be it a rifle or a pistol. The natural cycle of dragging from a magazine slows the bolt's forward travel a bit and is also far more friendly to every extractor.

[Erno86]

I had a slam fire happen twice...on my free floated firing pinned MAS49/56...when I had the rifle pointed at the backstop on our firing range, while single round loading it --- Using the standard mil-spec steel firing pin, on a 308 plastic German riot control round, with a 10 grain plastic bullet; that obviously uses soft primers.

I solved the problem, using an $80 titanium firing pin, instead of going the ink pen spring on the original firing pin route.

[stagpanther]

Normal for an AR or any rifle with a free floating firing pin.

Its rare, but a slam fire can happen due to this. Usually the primer is just unusually sensitive.


I have only ever heard a few second, third, fourth hand accounts of it though.

It has happened to me a couple of times over maybe the last decade of firing AR's a lot--though on one occassion I was asking for it by re-chambering a round that didn't go the first time. Many people say "Oh it's never happened to me"--but that doesn't mean much when it happens to you. If you reload yourself--the risks go up because uniformed pockets and properly seated primers are much more important. Because the AR bolt pin is a "sorta free float" pin it will strike the primer upon chambering. Get a slightly high primer--for whatever reason--or maybe a slightly "stuck" pin and "bang" you're off to the races. I haven't got them yet since I have a zillion Federal and Remmie primers--but I will switch to CCI NATO-grade primers soon.

[44 AMP]

Do note that the rifles that use a free floating firing pin are either designs intended for military use, or variants of the design of military weapons.

Most will work pretty well is non-military spec ammo, but its not what they were built to run.

My M1A always leaves a bounce mark on the primer. So far, never had one fire because of it, but I am aware it COULD happen, which is why we follow the rules of safe gun handling.

Firing pin weights are calculated so a slamfire should not happen. Should not, is not the same as cannot, and they should be treated as such.

[James K]

It will also happen with the M1 rifle, the ancestor of the M14 and M1A. I have never had an M1/M14/M1A actually fire when the bolt is let close, but I understand it can happen especially with commercial primers. Normally, the bolt will be locked and the only result is an unexpected "bang".

Jim

[ed308]

I've never had or seen a slam fire with AR or M1's in 25 years of being around them. Hope I never do. But I've several slam fires with AKs.

[Bart Noir]

Possibly related to this subject is the current recall of the Bolt Carrier Groups for SIG MCX carbines.

It is supposedly for the faint chance of a never-really-happened possibility of a unintended firing, although I have not seen slam fire mentioned. The details were not really in the factory announcement.

But what I have noted is that the new BFG has a bunch of changes, one being the addition of a firing pin spring. That may be what some call a "clue".

Bart Noir
Who realizes that the MCX is not a real AR, but thinks the bolt and firing pin are very similar. Until the recall.

[stagpanther]

I still think that just because "it's never happened to me in half a century of shooting" doesn't mean it absolutely can't happen. Whenever I load a magazine--I assume that not only could a slam fire occur; but that it might also dump the entire clip, so I make double sure I'm aiming at "something I don't mind destroying" and have a good hold on the weapon. It's never happened to me--but that doesn't mean it's absolutely impossible; to me.

[benEzra]

One of the best ways to combat a catastrophe is to only ever chamber a round from a magazine which is really the proper way to treat absolutely any semi-auto firearm anyway, be it a rifle or a pistol. The natural cycle of dragging from a magazine slows the bolt's forward travel a bit and is also far more friendly to every extractor.

Or if you need to load directly into the chamber, close the bolt slowly and then use the forward assist to snap the extractor over the rim. Single-loading by dropping in a round and hitting the bolt release would be the worst-case scenario for a slamfire.

Also, *never* use soft primers intended for bolt guns in any floating-pin semiauto. Use the right primers for the application.

[peggysue]

reloading

[hagar]

Use small rifle magnum primers only, and under no circumstances use Winchester small rifle primers. I have seen about a dozen slamfires on the highpower range through the years, and in almost all cases they were using Winchester. Saw one with Wolf small rifle (non magnum).

Friend of mine in AZ did not heed my warning (because he had a lot of them). The first slamfire with a Winchester just destroyed a magazine. He still did not listen. The second one destroyed his NM upper.

[jrothWA]

if the primer is slightly above the case-head. With a floating FP, an excessive protrusion above the case-head Could case an "not in battery" striking detonation of the primer.

Saw an occurrence with a M1A, when the shooter was firing at 600YDS, dropped a round onto magazine, then let the bolt fly home and BANG.


Found a second round in box with a high primer.

[wbstx38]

Perfectly normal for mil-spec free-floating firing pin. The key consideration is the primer. Mil-spec primers are tougher and take more to dent them. Also look and see if after firing you see black in the primer firing pin strike. This is a indication of a pierced primer, also not uncommon - you have probably had some and not known it. The simple solution is to stick to CCI primers and you don't have to worry about the mil-speck firing pin. (Pass on the Winchester primers.) On my 458 SOCOM AR I take a couple of thousands off the FP and polish it just to make sure I don't get a piercing.

[DMK]

I still think that just because "it's never happened to me in half a century of shooting" doesn't mean it absolutely can't happen. Whenever I load a magazine--I assume that not only could a slam fire occur; but that it might also dump the entire clip, so I make double sure I'm aiming at "something I don't mind destroying" and have a good hold on the weapon. It's never happened to me--but that doesn't mean it's absolutely impossible; to me.

Yep.

Not an AR15, but I had a 40 cal carry gun break the firing pin spring (what some folks are saying is a 'solution' to the AR15 free float pin) and jam the firing pin forward. I discovered this because I inserted the magazine, racked the slide to chamber a round and the slide would not go into battery. The rim of the round was stopped by the firing pin and jammed the gun.

When I saw that I got a cold chill up my spine knowing that if the round had not jammed and had chambered, I could have potentially slam fired 12 rounds of 40S&W through the outside wall of my bedroom and into the hill behind my house.

Now I religiously inspect the chamber and firing pin areas of my guns before loading them for carry duty.

[samsmix]

Seems like I'd heard something about fouling and dried solvent or lube conspiring to trap a firing pin in a forward position, with a slam fire resulting.

Seems like. It's foggy.

[stagpanther]

I recently had a pierced primer using an old 308AR bolt--the firing pin had developed a sorta ogive-like point from extended use instead of a rounded "half tennis ball"--I can imagine under the right circumstances the extra "penetration efficiency" of a sharp point could possible cause a slamfire.