First try to understand it on a basic physical level. Every time you shoot, the last link of direction that your wad of shot receives is from that thin cylinder of steel at the end of your gun.
"Today, most choke tubes on the market will be made with 17-4 stainless steel," says Roberts. "It is a must to try and find a tube that is also heat treated for maximum strength and reliability."
Roberts asserts that this specification will make for harder and more consistent steel, ultimately translating into better patterns.
Another major attribute to consider for choke tubes are the lengths of their parallel section. This is the part of the tube that extends out past the gun barrel. Roberts is a firm believer that the ideal length of a parallel section should be 1" to 1-1/8".
"I have researched and tested every possible parallel section length from a ½" to 2½" and have found that the best patterns are always present with the 1" to 1-1/8" lengths."
An additional feature of choke tubes that has both an aesthetic and functional impact is whether they're ported or non-ported.
"The whole idea behind a ported choke is the purpose of a wad stripper," says Roberts. "This means that the wad is separated more dramatically from the pellets at the exit point than a non-ported choke. Other than that basic feature, there are no other proven differences like a reduction in recoil or back pressure."
Roberts, who stands behind the performance of his non-ported choke tubes, says that the biggest factor is knowing what you want to get out of your gun's pattern, taking into consideration choke constriction and your gunning abilities.
Whether you are a waterfowler who desires to get a softball-sized pattern at 40 yards or one who needs a more open pattern for the in-your-face decoying shots, any pattern can be accomplished with the right combination of choke tube and load. Without having a basic understanding of how a choke tube functions or what to look for, it can become a guessing game with the potential for inconsistency and frustration.