What causes light primer strikes?

[combatvet]

Why would an AR15 have a light primer strike and what causes it.

Ammo?

[talbalos]

The free floating firing pin. It's normal.

This is why you never let your muzzle cover anything you don't want to destroy. Especially when chambering you want the muzzle aiming down range or in a safe direction.

Military ammo uses harder primers. Fortunately modern primers are also designed to be safe with free floating firing pin designs.

[Eric]

If you're talking about light primer hits upon pulling the trigger, it can be caused by a weak hammer spring or improper installed (in backwards) hammer spring.

If you're talking about the tiny marks left on the primer when chambering a round... what talbalos said.

[TWR]

nevermind

[Snake RAH]

Add two more:

Blunted firing pin.

Excessive headspace.

Firing pins wear out. They make a gauge for it, called the "firing pin protrusion gauge."

Excessive headspace won't always be the cause of light primer strikes, but if it is excessive enough, you will occasionally have a "click" instead of a "bang" and you'll find a unfired cartridge in your chamber. EH is least likely here if you have a decent AR.

[Robb Jensen]

Why would an AR15 have a light primer strike and what causes it.

Ammo?



Weak hammer spring
Incorrectly installed hammer spring
Hard primer, (bad ammo)
Bad firing pin (not enough firing pin protrusion)

If shooting reloads:
Low primer (sits below the edge of the casing)

[combatvet]

GotM4,

You were correct CJGarza's rifle was experiencing LPS, the hammer springs were on incorrectly, he fixed them, this is dead issue. Thanks.

[Kisara]

This caused it for me:
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=7582&title=AR-15+REDUCED+POWER+SPRING+KIT

It did make a notable difference in feel, especially with longer range followup shots. But this item should be used strictly for a range/target gun, not on a fighting weapon you would trust your life with. I stick with factory Colt LPK.

[HAMMERDROP]

carbon build up inside the bolt around the firing pin, is it the first round in the magazine with light primer strikes or 5-10 rounds down the column if its first round pull the firing pin clean and clean the inside of the bolt to allow proper function. If the incident occurs several rounds into the mag could be hammer spring like TWR said ...

[Heavy Metal]

Incorret lub on firing pin in cold weather. Ask me about Bill Horn's special IPSC sauce and a near freezing day.

Did not run his AR so well.