Welcome to Johnny's Shotgun Chokes and Forcing Cones... Twenty years ago, the most requested alteration to a shotgun barrel was screw-in choke tube installation. Twenty years ago, the least (almost never) requested alteration to the shotgun barrel was lengthening of the forcing cone. This has all changed. Over the years shooters have become much more educated in this area. In the beginning most customers didn't know what the forcing cone was and didn't understand its function or what I wanted to do to it. Now days I find that a large percentage of the people who call me already know they want the forcing cone done, they are just calling for clarification and details on their particular barrel. Twenty years ago, I was confident that lengthening the forcing cone worked but, in the beginning, most of the evidence that I had was just based on my own testing. Now, with 20 years of customer feedback from lengthening and polishing hundreds of forcing cones, the evidence is overwhelming that this forcing cone thing does work. I still make it a habit to check the forcing cone on each barrel that comes in for choke work to see if it has been lengthened. If it has not, I always mention it to the customer because not everyone is familiar with it, but this has changed drastically over the years. Now days a large percentage of my new customers get my number from a friend or from someone at some type of competition like card shoots or trap and skeet clubs. My customers are my biggest promoters. I also learn so much from my customers and it is amazing how many of them will call me to tell me how my forcing cone work improved their patterns. There are guys out there that do such extensive patterning that it is almost a second hobby. These are the guys that, over the years, have educated me as to how my work affects their barrels much more than I could ever learn by my own testing. Below I will explain the forcing cone, what it does and how it can be modified to improve the performance of a shotgun. The Mysterious Forcing Cone The forcing cone is the constriction at the end of the chamber that forces the load down from chamber size to the size of your shotgun bore. If you hold the barrel up, point the muzzle toward the light and look through it from the chamber end, the forcing cone will appear as a short, dark ring, dark because the angle of the short forcing cone is severe and is hidden from the light. The distance from the beginning to the end is about 1/4 - 1/2", give or take. Most barrels come from the factory with this abrupt constriction, or forcing cone. When the shotgun is fired, the shot load is immediately FORCED, under tremendous pressure, to squeeze through the abrupt forcing cone to the smaller size of the bore. The shot in the back of the load move first and they have to push the guys in front of them through that abrupt forcing cone. This results in some of the lead shot becoming deformed, making them ballistically unsound and causing them to fly out of the pattern. Lengthening the forcing cone by changing the abrupt angle to a more gentle, gradual constriction results in a new length of around 1 3/4" and a much more gentle angle of constriction. This optimum new length and less severe angle from chamber ID to bore ID allows the shot to make a more gradual transition from chamber to bore size, reducing shot deformation and allowing more of the shot to remain in the pattern. Cutting this new forcing cone is about half the job. The second half, which is usually overlooked, is the polishing step. It is extremely important for many reasons, which I explain on another page called "Proper Forcing Cone Polishing." I can tell you that I took a brand new barrel that I bought for my son, and being short on time and ready to go hunting I did a quick forcing cone alteration and decided to save the polishing step for the next day so we could go. We went out and hunted, the gun was fired several times, and when we got back I threw it in the safe and forgot about it. Three days later I was in the safe and remembered that I needed to finish that job by polising the forcing cone. What I saw when I looked down in there was amazing. The forcing cone was a mess with a good coating of early surface rust and contamination. Had I left it in there like that for a longer length of time it would have been a total mess. That's when I realized that the polishing step is for more than just performance, it is for closing up the pores on that bright new forcing cone to stop it from rusting and to make it easy to clean. I had to put the reamer in there and take a few more turns to get back to fresh metal again and then I put the polishing job on it. That never happened again. So be sure that if you get your forcing cone lengthened that the polishing step is part of the deal. Guys don't like to do it because it takes so much time, but it has to be done. Please read more on polishing on the other page. Continue to The Shotgun Choke>>>