Slam fires in Mini-30

[Old Griz]

I was trying to sight in my Mini-30 last week and it began slam firing. Did it 2-3 times per 10 round mag. What could be causing this and what can be done about it?

[Bugflipper]

 I would look into the firing pin first. Make sure the bolt isn't gummed up bad on the inside with powder, making it want to stick. http://www.midwayusa.com/General.mvc/Index/Schematics~ruger_mini_14

[Hooker]

Remove the bolt and check it the firing pin is a free floating style.
If you turn the face of the bolt upward the firing pin should fall back into the bolt with nothing sticking out the face of the bolt
Then turn the bolt face down the firing pin should protrude out of the face of the bolt.
The try forcing the firing pin forward to see if it sticks.
The firing pin should move freely if it's hanging any in either position it may be dirty or bent.
Firing surplus ammo or Wolf ammo is very hard on the firing pin as the primers on these types of ammo are very hard and have been known to cause firing pins to break.

Pat