375Brno, I didn´t realise it was so hard to get 2 1/2 " shells there (or in USA for that matter) ?? What sort of value is the gun you are using ? If it is not a top end name but in good condition it is a realatievely easy job to take the chambers out to 2 3/4". It won´t be possible to sell it in UK as it will be out of proof, do you have a proof house in Oz ?? You need a GOOD gunsmith to do this and to know the barrels are OK but if they are, this would be a far cheaper route though if you are going to shoot a pallet or so, why bother ! best, Mike