In 2010 Tranter was approached by the proprietors of Boss and Co to examine the reintroduction of the Robertson shot gun line. The family Robertson owned Boss over a century ago and had produced a range of very high quality box lock shot guns that were produced in Birmingham and finished in London. Tranter took the basic Boss concept and in conjunction with Boss engineers produced a range of 20 bore side-by-side shotguns and a limited number of 12 bore over and under shotguns. Various illustrations of the development work and complete firearms may be viewed under the gallery section. When Boss was sold in 2016 the Robertson activity was put on hold pending the requirements of the new owners.
Tranter is currently developing its own proprietary range of over and under shotguns.