Box Mags Fall Out of Big Game

[Essex]

I have an Impulse Big Game in 30-06 that uses the standard Savage large box mags. I periodically have a problem where the mag just falls out of the receiver when I fire. I have tried multiple mags, make sure its locked in as much as possible everytime I load, and it still happens, maybe 1 out of 4 shots. Anyone else have this problem, thoughts on a fix?

[shoots100]

Savage factory magazines are well known for their lack of quality. so I think it would be prudent to buy some spares and work on them to find a fix.
It locks in, so I would look at manipulating the locking area if possible.
As was stated in earlier posts, that's the main reason I bought the Predator model, No dealing with factory mags.

SJC