I stumbled apon a bag of rifle rounds. the only marking they have is on the bottom 60 66. any help?

Here is a SWAG (Scientific Wild A** Guess).

What you have is round with what's called a 2 element headstamp (That's the name of the marking's) with one element being the manufactuer code and one being the year.

That is generally Communist made ammo (ComBloc, China, North Korea). 60 is the manufacturers code for the Russian State Factory at Frunze, Kirgisia, Russia. 66 would be the year.

So my guess would be 7.62x39 from the AK-47. It could be 5.56 NATO (.223) but I highly doubt it seeing it was designed in '64 and I see no reason for the USSR to be copying it. If you post the length I will be able to tell you what it is with more certainy. A pic would help as well

PS. It's called a "primer" not a striker plate. But we knew what you meant.

If they're in an unmarked bag, they're probably someone's reloads. Take them to your local range and ask them to dispose of them for you. You don't know who reloaded them or to what pressures or whether they made any mistakes.

I wouldn't risk my life, not to mention my rifle, on something like that. I advise you not to either.

Get out a ruler and go to the link in first answer and take some measurements or take one to a gun store.

Where did they come from? Ask all occupants current and previous what they fit.....or just send them to me :):):).

If you are unsure, I would take a round the your local gun shop. They should be able to identify the round by looking at it or by comparing it to other rifle rounds.

Get a caliper and compare dimensions to this web page of cartridges.

http://www.stevespages.com/page8d.htm