The top extensions are (in no special order):
The Remington Factory.
Second best is the Tac-Star.
In a very distant third place is the ATI plastic unit.
The Vang, Remington factory, and Wilson are EXPENSIVE.
The Choate and Tac-Star are around $40.00.
The ATI is around $25.00.
The Wilson, Vang, Choate, and Tac-Star are easy to get.
The Remington factory is hard to get due to Remington not wanting to sell them too widely.
The Tac-Star has some history of factory defective units.
The ATI is a plastic unit moulded around a steel coupling nut.
Price-wise my pick for best is the Choate.
The Choate is strong, and has been made and widely used for more than 30 years.
It comes as a complete kit, with the extension, high-quality long spring, a stronger follower, AND the all-important barrel clamp with a sling swivel.
The others come without the clamp, and often without the swivel.
The Choate is available in black sulfate or parkerized finishes, and in any length from a 7 shot for 18" barrels, up to a 10 shot model for 26" barrels.
Whatever you buy, USE THE CLAMP. If the extension doesn't come with one, BUY ONE.
People look at the Wilson or Vang and assume that since they don't come with a clamp and they are strongly built, they don't need a clamp.
It doesn't matter HOW strong the extension is, it could be a solid steel bar.
It's still screwed to the end of the gun's magazine tube, and the magazine tube is thin steel, further weakened by the deep square threads.
Give a extension a not-to-hard bump, and the extension can be knocked out of line, or worse, knocked completely OFF the gun.
Invariably, this damages the gun's magazine tube, and this requires a trip back to the factory for a replacement.
This is expensive.
Knocking the extension off a gun not fitted with a clamp is not all that uncommon. I've personally seen several cases of it happening.
Bottom line on clamps: There's NO valid reason NOT to use one, and several excellent reasons TO use one.
I don't know if he's still in business, but this man sells all the Choate accessories and clamps at great discounted prices:
Eldon King -- [email protected]
Brownell's sell about everything available for shotguns also, including most of the extensions.