what will make a string come off when you shoot?

If you were in the woods maybe a twig came in between the string and your bow while drawing. Its happened to me once before

Twisted limbs?

loops too big?

Take a close look at the string in relationship to the limbs when strung.... I'm betting this is a recurve. If the string doesn't track straight down the middle of the curve then you have a twist in the limb.

That's the most likely culprit.

Sounds severe, but might be fixed by warming the limb under hot water from the tap and twisting it back into place... you will have to over twist it.

The bow has probably been subjected to improper stringing. If you don't have one, buy a bowstringer.

nope charlie itsa long bow,  and no there was nothing between the string and the bow. it happened 3 times in a row.

Follow the suggestions above and check your limbs for straight.
Your string grooves could be worn and/or built up with wax. Either way you can check it out and if need be, file it yourself with a chainsaw file, or have someone who knows do it for you.
Just make sure there are no sharp edges and everything is smooth smooth when done.

thnaks bjorn,,  i was thinking about the string groves,cause they are extrem; small.

I've experienced this once, and heard about it once.  On the bow I experienced it with, the string grooves were cut at the wrong angle on the top limb--had it worked on, problem solved.

On the one I heard about, the string grooves were very shallow and the string was too "fat" in the loops, so it wouldn't stay in the shallow grooves.  A smaller diameter string fixed that one.

Chad

I've seen it happen with one longbow: string loops that were too big on a bow with the grooves cut at too steep of an angle.

thanks alot guys,  i do beleave that it is a combination of string loop too big and string nock too shallow