Bushmaster misfire

[ebuckler]

what might cause a clean and not very old AR to misfire occasionally? I had some very old rounds and at first I thought perhaps that was it but after discounting that I noticed on the next failure that the primer seemed to have not been touched. Chambered a new round, and fired no problem. It doesn't happen often but it happens. It has been cleaned completely and as far as I can see no damage or undue wear on any part. Ideas or places to start? Please.

 

[KillerFord1977]

Firing Pin not seated correctly would be my initial gut reaction.
Have you taken it apart ever to clean ? not seated correctly after put back together ?

 

[10mmLife]

Is your rifle going into battery completely?

Are you riding the charging handle back or do you sling shot it?

 

[ebuckler]

I have several times, but if the pin wasn't seated correctly wouldn't it misfire on every shot? it just does it sometimes. I might fire off 10 or 15 rounds then *click*. extract and chamber next round then *bang*.

 

[ebuckler]

Is your rifle going into battery completely?

Are you riding the charging handle back or do you sling shot it?

I draw the charging handle back then let it go.