AR Dimpling Primers On Chambering?

[Mick_In_Texas]

A bit of an aside for me, as I'm still working on my M4A2 Bushmaster in .223/5.56.

A work buddy has an AR15--I believe he said it is a Bushmaster as well--which is a "working rifle", that is, carried loaded and locked on various jobs out in the woods and in fields. Stated he keeps it unloaded until arriving at a work location; then chambers a round from a full magazine and engages safety. At end of job, stated he releases the magazine, and clears the round in the chamber.

His is also .223/5.56. Stated he noticed after latest chambering that the round chambered had a "ding" in the primer--he was surprised it did not cause the round to discharge! He stated the only thing he can think of is that the rifle firing pin "dinged" the primer when he chambered the round.

Obviously, he's a bit upset and very concerned.

I've chambered live rounds (loading from magazine) in my Bushmaster M4 to check function, and I don't see any of them where the primers appear damaged. I'm sure if this has happened to others, you folks will know about it.

Any comments or thoughts? I'll pass on to my buddy if so. Thanks, all. Y'all be safe and have a good start on the weekend.

Mick

[Buck]

This is a very common occurrence, most M16s / M4A1s that I have used do the same thing... I have personally observed innumerable rounds of duty ammunition chambered in work guns and never seen, or ever heard of anyone having an AD from this…

That being said..

Rule # 2 ) Never allow the muzzle to cover anything that you are not willing to destroy…

B

[Failure2Stop]

It's absolutely normal for the inertia of the firing pin to dimple the primer upon chambering.

No cause to be alarmed.

[Steve in PA]

All rifles with a free floating firing pin can and often will, leave a slight mark on a chmabered case. AR's, Garand's, Carbine's, SKS's, etc.

[Ring]

on my varmint upper i solved this by adding a titanium firing pin

[Mick_In_Texas]

I'll pass on y'all's sage advice.

I think Buck's "#2" is good guidance, though! Loaded gun=don't point at anything you don't want to shoot... be it dresser, floor, wall, or...

Good folks here. The gentleman also has (Steve in PA) a Springfield M1A and some kind of ".222" rifle... I myself have a Chinese SKS as well in 7.62X39mm NATO. I know on the M1A he's had feeding issues with less than "mil-spec" ball ammo; don't know that he's mentioned primer dings on the .308/7.62X51s there... but, I know he's said his probs are partially because that bolt on that thing SLAMS HARD. Me, I like factory loads in standard chamberings, from my 9mm, 1911s, to my Mossberg shotgun and my SKS and M4A2.

Again, thank you all. There may be more responses, but hope to see the dude tomorrow. I'll definitely share this information with him, not only in re: his AR15 but his other two... I'm thinking to take my M4 to work tomorrow, too, just for kicks. He's never seen an M4 version in real life. He's good folks. 'Course, I'll have to park "off-site". That's okay. I need to get it to my FFL/gunsmith for a little castle nut staking.

Y'all are good folks. Take care and have a great start on the week.

Mick

[Mick_In_Texas]

on my varmint upper i solved this by adding a titanium firing pin

You like that titanium firing pin? My two Springfield 1911 pistols have those... which my other 1911s don't. My SAs work fine. Did you change your fp spring for it? Just curious, and learning. Thank you Sir. You and yours take care and be safe.

Mick

[carbinero]

My four ARs all did that, and for peace of mind, I rotate the top round, so no round gets the dimpling twice.

Freaked me out a little the first time, too.

I don't see a good reason to go titanium FP, so if any M4C pros out there do, please tell.

[Parabellum9x19mm]

titanium firing pins are bad mojo. dimpled primers are normal, so its not a "problem" that needs "solving".

what the point of the Ti firing pins? decreased lock time or some other such mumbo jumbo :rolleyes:

i wouldn't ever use one. that's just me tho. use whatever works for you, but i dont see the point

[sff70]

Very normal and not a concern. You can also rechamber the same cartridge repeated and there will be no further dimpling/no detonation of the primer.

That's what the Colt AR15/M16 armorer's class teaches.

My 19 yrs of experience with ARs and M16s has squared with this.

[Ring]

You like that titanium firing pin? My two Springfield 1911 pistols have those... which my other 1911s don't. My SAs work fine. Did you change your fp spring for it? Just curious, and learning. Thank you Sir. You and yours take care and be safe.

Mick

the Ti pins does nothing for your gun other then stop the primer dents, the only reason i have it, was i got it for free.......

[Failure2Stop]

I myself have a Chinese SKS as well in 7.62X39mm NATO.

Just a little nit-pick- there is no such thing as a 7.62X39 mm NATO. The established NATO small-arms rifle ammunition is limited to 5.56X45 mm, 7.62X51 mm, .50 BMG, and 40 mm. Whether 40 mm falls into "small arms" category is debatable, but generally accepted.

As far a titanium firing pins in an AR- there have been instances of the firing pins chipping and resulting in pierced primers, which is sub-optimal.

Just FYI.

[Mick_In_Texas]

My buddy took the day off today, since we're off for Veterans Day. That is apropos.

Interesting to know, that the 7.62X39mm round for the SKS and AK47 is NOT a NATO round, like I really care what NATO "approves", LoL...

DOES sound like my buddy's primer dimpling is a fairly-common occurence, though. I do agree with exercising common safety procedures, like pointing a weapon in a safe direction from my Ruger GP100 through my 1911s to my shotgun, SKS, and M4A2 when chambering a round. Just makes sense.

Frankly, I like steel or stainless steel firing pins. I have an ss M16 fp to help disassemble my 1911 platform pistols; while my Springfield Armory 1911s have titanium (and more 9mm than .45ACP) firing pins, and work well and very reliably, I like OEM stuff in my guns... as long as they work. I wouldn't knock the titanium in an AR15/M4, but if it ain't broke, don't fix it is pretty much my motto.

I think my work buddy just needs to exercise sound safety and handling procedures when chambering a round in that AR15. That goes for any of us, with any firearm. Duly noted, for my M4, though, in the future! Like we all know, the ULTIMATE safety is our own common sense and knowledge of safe handling.

You folks are the salt of the earth! Thank you. I know my work buddy will appreciate the information. Frankly, I hope to go to a pistol range tomorrow... to celebrate a special day in the U.S.... but, y'all, I am so itching to fire my own M4. Hard nowadays in an urban environment... and that's really sad for law-abiding citizens. We'll see, though. Still want to take my M4 and show it to the guy. And get some 20-rd Magpul polymers to supplement my 30s from G&R Tactical.

Me, my buddy, and y'all are NO threat to anyone... legitimate. There you go. Y'all all take care and be safe.

Mick