I likely used an incorrect term for accuracy testing. As I understand it, the 1855 model was the first mass produced infantry musket to have rear sights. I don’t know if there is documentation for that decision, but it might represent the first glacial movement toward interest in longer range accuracy for line troops. The Army did extensive range testing of each new model, so the arrangement of the sights must have been a well established specification that finished rifles were compared against. Ideally. It may very well be that windage correction capability did not have a high priority at that time, so my rifle might simply shoot left. As we know, the muzzle loading infantry rifle was obsolete before 1861, but it had the advantage of faster production at 1/3 the cost. The start of wars are certainly come as you are affairs. My thanks to everyone!I thought "proofing" was to certify chamber pressure safety not barrel accuracy.