Bakers gun wasnt a 2 bore unfortunately. Folks read the 1/2 pound and do the math assuming a roundball but Baker never says roundball in connection with it or uses the term 2 bore in any of his writings. I think even Treusdale and Jack Lott have misquoted it over the years.

This was hashed out a few times on AR over about 20 years and someone actually referenced it and its seriel number and it checks out closer to 3 bore. apparently Which means the projectile or shell as he refers to it as was conical or some other longer shape of smaller diametre.

As to whether 2 bores existed, the calibre is certainly covered in punt gun sizes. As to whether there was a dedicated 2 bore used for safari purposes I have not seen any evidence except for one passage which I read in the early days of the net, and have not been able to find since. Mentioning a gentleman 'Gibbs' using a true 2 bore with half round ball, they even mentioned the load of black he liked. However it was just a few lines on the old style AR website and I am not sure if it was fact or a line of fiction from a book. I could not find it in 2004 when the subject was raised again nor any searches I have done since.