in the game it talks about the events in the cold war...now is most of this information true like when GEN.Volgin used the davy crocket on the professors weapons lab...or is there anything similiar to that...any other information is also good to...

Well, that isn't true.
And most of the stuff happening in MGS3 in which Snake, Volgin or The Boss etc were involved in, any information that happened there were kept under wrapts by the American Government, so to speak.
So, that kinda stuff were never put in the history books, or released to the news.
The American Government would not even let that information out, since they were partly behind it to sett up a plan to let The Boss defect to the Soviet Union, but the plan kinda backfired when Volgin suddenly fired the Davy Crockett, and then that plan got expanded, in which Snake got the orders to take out Volgin and the shagohod, and elimating the Boss, to avoid a nucluer war, and the Boss knew that she had no choice but to play out her part, and let herself be terminated by her own Apparentice, she knows that's the only way to stop a World War 3 or worst to becoming from happening.

But the stuff about John F. Kennedy avoiding a Nuculear holocaus and stuff like that were true, and those black and white movies from that era.

And the events that the Boss was talking about in the end with actuall footage in some were partly true, but what she did were never put in the history books, she says that a couple of times.

This story is fictional, but it has some actuall historical elements and events in it, but those are merely background stuff because of the era the game plays in.