Dimple in primer...

[Preacherman]

New Ar 15 pistol build
Whenever a round is chambered the firing pin is putting a shallow dimple on the primer. After inspection the firing pin is bent a little and my guess is that the buffer spring is too long causing to much force. Any other ideas or is it too long of spring?

This is not an admission that I own this fire arm. I really don't but my nephew maybe does.

 

[O4L]

From what I understand this is normal for some AR guns because the firing pin floats and when the bolt is closed with full force the pin slides forward putting a slight ding in the primer.

 

[Preacherman]

Thank you. I tested two others and they do the same thing. I never knew that but I guess I would if I owned any firearms.

 

[HFS]

From what I understand this is normal for some AR guns because the firing pin floats and when the bolt is closed with full force the pin slides forward putting a slight ding in the primer.

That's my understanding as well.
I've been told that dimple on the primer from the floating firing pin is the reason 9mm AR bolts usually have a firing pin spring (pistol primers are made of thinner stuff I guess and the dimple might be bad news).

 

[SPDguns]

From what I understand this is normal for some AR guns because the firing pin floats and when the bolt is closed with full force the pin slides forward putting a slight ding in the primer.

This is correct.

 

[mr ed]

It's dangerous get rid of it. Give it to me, we're going on a boating trip to Grand Lake this weekend.

 

[Rez Exelon]

I had the same question and went full on into "oh crap" mode when I first noticed this until some people pointed out it was normal and common. I hadn't noticed it for years but sure enough when I tested a few ARs they all did it.

 

[dennishoddy]

You wouldn’t believe the tub of .223 and 5.56 unfired rounds I have with the little dimples in primers. I guess they think they are duds and put them into the live round containers scattered on each range.