Someone once told me that if you opened a tin of beans or whatever today, which was tinned in 1940 they would be absolutely fine to eat. I'm not too worried about eating certain tinned food if only out of date by a few months but is that true of all tinned food? For example could the same be said for luncheon meat or corned beef?
Use before is different from Best before. I use all sorts of out of date things if they are best before, but would be very careful of use before, especially sausages and meat products. After all, who knows what goes into them?