I have shot 3 different guns in the few years that I have been shooting. The Beretta had certain chokes, loads and shot that it liked. My .740 bore Kolar only liked #8 shot. The new .750 bore Kolar has, so far loved everything I have fed her. Bill Malcolm
Some approach the job of back boring a barrel incorrectly (my opinion). Step one is to pattern the gun with a specific load you intend to shoot. Next, analyze the pattern and determine how it needs to improve. Then have the skill and knowledge to know how the internal shape of the barrel can be changed to achieve the desired result.
Good barrel men will do very different things to different barrels to get the result they want. At least one (Tom W.) has sent many barrels back to their owners and told them nothing needs to be done.
Unless you identify the problem first, how can you solve the problem. There are some others who just want a barrel and will cut some metal out of the barrel and tell you it is back bored.
thanks guys but here is the whole truth, I Just bought a Remington 11-87 Trap and called Remington with the serial number to get the date it was made, I also ask them if this model was factory backbored and they said yes. In the past I bought a new Remington 870tc that was backbored and came with 3 chokes, trap full, trap extra full and trap super full, If you checked the constriction of these chokes the super full was about the same as an imp.cyl Regular chokes shot terrible in this gun and these chokes shot terrible in regular guns. I have'nt had a chance to pattern this 11-87 I bought but was just wondering to start with an open choke or a tight choke? That is why I say I don't understand backbored barrels.
The choke tube function is related to how much constriction it has from the backbored barrel. So, if the barrel is bored to .740" and the choke measures .710, the constriction is .030" while if that same tube was put on a barrel that measured .730", the constriction would only be 20 thousandths. Choke size must be related to the bore size....breakemall....Bob Dodd