Jerry The 9lb 1835 bronze field gun and the 9lb confederate bronze field howlitzer had 4in. bores. The solid shot fired in these measured around 3.940 in diameter. The confederate two barrel 4 pounder had a bore of 3.13 and fired solid shot sround 3.090 in diameter (one of these guns still exist) In the Warman's civil war collectibles 2003 edition book on page 117 they list an 8lb solid shot from the Augusta Arsenal.(The picture they show appears not to be a solid shot.) On page 121 they list a 4lb solid shot from here in Missouri, lexington (the battle of Lexington) they have the size at 3-1/8. The civil war artillery page under encyclopedia shows bore sizes. From what I understand a lot of these old guns no longer exist. I am no expert but I try to research as much as I can on the the items I own. I appreciate all the help anyone can give me. The sizes and concentricity of solid shot vary due to casting. I measure each cannonball and artillery shell that I can to try to find consistencies. THANKS lARRY