did winchester mark there receiver and barrel with a 1/2″ line to know properly mate the two?  I recently purchased a touted 98% gun by LSB and at the 4 o clock position hidden by stock was the line.  I have not noticed this line on other guns, but I did see a pic of the line on another model 72A…not sure if it what some gunsmiths do when they reblue a barrel, etc?  thanks.