scope focussing

[sandman]

hi all
have a problem with my besonder scope 10-40x50 after each shot it will go out of focus for a few seconds & some times when aiming can any one tell me why thanks

[The Burpster]

My guess without seeing it or you, is that it is
a) a shonky scope.... (even very expensive scopes are sometimes defective!)
b) something to do with your technique for settling to shoot, and your eye relief is fluctuating a bit... any small issues will be greatly embellished with big mag 'scopes.

[Gary C]

You have a very cheap scope with a very high mag. It's a somewhat "fraught" combination.

[sidesy]

try it on a lower mag and slowly go up in magnification...
adjust parallax , see where it "goes " awry...
could be as described ..YOU..not putting your head back in the exact same position (sounds impossible but we do)
or, a mechanical problem...OR, perhaps both. Can only be vary vague without seeing you and it, in action..
To be honest, its a hell of a spec for a low grade scope (no disrespect)...get someone else to look through it or change / borrow a scope......