Pump-action shotgun: Press the shell latch behind the magazine and pull out all the shells as they emerge. After that, hold down the bolt release (near the trigger guard) and slide the pump back—a shell will eject each time you do this, until the chamber is empty. Visually inspect both the magazine and chamber. Auto-loading shotgun: Slide back and release the bolt grip to eject a shell, and keep repeating the process until no more shells eject. Visually confirm that the chamber and magazine are empty. Break-action shotgun: Open the hinge and pull out the shell(s) in the single or double barrels.
For the best results, use the choke tool that came with your shotgun and its accompanying set of interchangeable choke tubes. Otherwise, contact the shotgun/choke tube manufacturer and order a replacement tool.
If the choke tube is stuck in place and you can’t get it to budge, your best bet is to take it to a gunsmith—trying to force the tube loose yourself is likely to damage the barrel.
If your choke tool doesn’t have a threaded end, use the choke tube you’re about to install to accomplish the same task. Wipe down its threads thoroughly (if it’s not brand new), finger-tighten it in the muzzle several turns, unscrew it, and wipe down its threads once again.
Don’t skip this small but important step. Lubricating the threads will make it much easier to install and uninstall the choke tube.
Starting out by hand (instead of using the choke tool) makes it easier to feel that the threads have taken hold. This will prevent you from mis-aligning the new choke tube and potentially damaging the threads.
Some specialty choke tubes are designed to extend beyond the muzzle tip. In this case, just focus on fully tightening (but not over-tightening) the tube. Unscrew the tube and either try again or consult a gunsmith if one or both of the following happen: You can’t screw in the tube any further unless you use maximum force, but the tube isn’t yet flush with the muzzle tip. The tube is already flush with the muzzle tip but still feels like it can be tightened further.
It’s easy for a DIYer to cut the new threads improperly so that the choke tube doesn’t fit right. Even worse, you might hollow out the end of the barrel too much, causing it to crack or even explode when you fire a shell.
The choke tube names listed here—skeet, cylinder, etc. —aren’t universal, but are commonly used. In general terms, choose a choke tube that’s less constricted for greater shot spread, and more constricted (or full) for narrower shot spread.
