Ditto what stubblejumper said. Your gun friend hasn't got a clue.

The 270 is way more than enough gun to take deer. Mine takes an elk every year with no problems and unless the elk are shrinking......... The 303 british is a low pressure cartridge and if you do some research on the two cartridges you will find that the 270 will provide better velosity, energy, and balistics than the 303 british. The gun (receiver) itself is of a weak design and I would stay away from it all together.