Shotgun Mysteries: Which Modifications Work?
The term was allegedly coined, and certainly popularized, by the late Stan Baker, of Seattle, Washington. Mr. Baker pulled up to .070 inch or so out of his barrels, and various entities have claimed "better" patterning, less recoil, and one thing that is a matter of fact, less weight.
What factories tout as "back-bored" barrels are not back-bored at all, they are merely over-bored. From what I've experienced, this is more of a "placebo effect" than anything else, in addition to being a marketing tool. If you believe in physics, free recoil actually increases as your gun now weighs a small amount less with true back-boring.
The recoil assumption is overstated, even misrepresented, and the theoretically better patterning is a long way from being clinically proven. A 16 gauge is as superior to a 20 gauge as it is inferior to a 12 gauge in the sense of forgiveness, ability to handle larger shot sizes, and pattern efficiency with a bit heavier payloads. If you could back-bore a 20 gauge enough you might eventually reinvent the 16 gauge, obsoleting the 20 gauge if the back-bore theories held great value.
Back-boring seems to achieve nothing significant in terms of patterning, but does help balance muzzle heavy scatterguns. Certainly, both "standard" shotgun bores and overbored barrels both can produce excellent patterns. Whether a shotgun is marketed as back-bored or not has little correlation to how it might actually perform.
II. Lengthening the Forcing Cone
Factories can naturally make their forcing cones as long as they would like, at little extra cost. By now, if it was a well-documented fact that longer forcing cones clearly improved patterns, it would be absurd for any relatively expensive competition clays gun to be produced without this fabulous feature. That has never been the case.
In the quest for better patterning shotguns, lengthening forcing cones ranks low on the list. Many of today's shotguns have hard-chrome lined bores, a fairly inexpensive process that makes cleaning easy, and also deters corrosion. To modify a forcing cone, what must happen is the removal of this hard-chrome lining. Now, the polish of the forcing cone becomes critical. A rough forcing cone picks up plastic and powder residue, and may make your patterns quickly go the wrong way.
A smooth forcing cone is important to consistent performance. A bad forcing cone job is far worse than no forcing cone work at all, and it sure is difficult to sand metal back on after modifications that hurt more than they help.
It may "help patterns up to 10%" as some claim, but anytime you hear the word "may" it should also tell you that "may not" is a possibility as well. Quality operations such as Kolar Arms of Racine, Wisconsin do extensive one-on-one work and in-house pattern testing for the individual gun (and person) with whom they are working.
As with expert rifle-smiths, expert shotgun-smiths "have their ways" and pet approaches. This is an area where science and art meet, and there are many ways to break a bird. I mention Kolar Arms, not to discredit any other custom shops, but because I believe they are as good as it gets. They can help get you where you want to be, provided you know what you are looking for. Kolar shows you the "before and after" results.
III. Porting Shotgun Barrels
It may be trendy, or less so as time goes by, but as a generality porting does nothing remarkable as to function. It does irritate the shooters next to you, and puts more holes in what was a perfectly good barrel. There isn't enough residual pressure at the port area in a shotgun to reasonably equate to a high-power rifle muzzle break, and the muzzle flip on a clays gun is nothing remotely like what you'll find on a pistol.
Less felt recoil can be found so much easier with a longer stock length, proper Limbsaver or Kick-Eez pad, and gun-fitting. No fixed breech gun of the same weight compares with the longer, broken-up recoil pulse of a gas operated gun. Sure, I've invested (wasted) my fair share on ported shotgun barrels. Perhaps the extra noise obfuscates the feeling of recoil, but if it offers anything substantial, my shoulder has not been able to detect it. Necessarily, on an Over / Under shotgun, ports cannot be placed where they would do the most good, as there is an upper barrel in the way. Since recoil is obviously of interest to so many folks, it is covered elsewhere on this web site.
IV. After Market Chokes
Just like rifles, we seem to have a tough time accepting that shotguns are all individuals, no two patterns are alike, and no two shells perform identically, either. After market choke tubes can and do improve patterns, and the 100% quality control built into the better after market tubes is a clear edge over many factory tubes.
It is an easy change to make, as long as we accept that all of the variables present prohibit global judgments as to how much, if any, patterns will be improved by after market tubes. In some guns after market choke tubes significantly improve patterns and can bag more birds for us, or break more clay, as the case may be. Other guns may show no improvement at all. Briley or Carlson's can help, and there are others who make good tubes as well. Patterning is requisite to find the combination that excels for any one shotgun and specific shell.
V. Trigger Work
Once you have a really great trigger, just like air conditioning, you really don't care to be without it. It can make a huge difference in the field and on the clays courses as well. The best that I've used is Allen Timney:
Allen Timney Gunsmith
Give Allen a call if your triggers are not up to snuff, and be prepared to be amazed at what he can do. Allen has no idea he's being mentioned here, one of the reasons I've done so. He is really good at what he does. Mr. Timney will make a "trigger" believer out of you, too.
Copyright 2006 by Randy Wakeman. All rights reserved.