Beretta currently uses (or recently has used) 3 different choke tube types on different models of shotguns. They can be identified by the image below. Note that all the tubes pictured here are flush tubes. There are several styles of extended tubes with different styles of extension, but the part of an extended tube that goes inside the barrel will match one of the flush tubes illustrated below.
Thanks to Worc for helping with the picture.
There is a fourth choke tube type that was used on a few of the first guns Beretta made with choke tubes. The tube itself has no threads on it, but it is held in place by a collar that screws onto threads on the outside of the barrel.
A warning about interchanging tube types.
Beretta has created a confusing situation with the use of three different choke tube systems (four, counting the old drop-in, collared type). It gets even more confusing when you consider Benelli choke tubes. Benelli is owned by Beretta, and they have recently brought out several choke tube types that appear similar to the Beretta Optima and Optima Plus tubes, but are designed to be used with a bore diameter that is different from the Beretta Optima bore. To make matters worse, as far as I can determine Beretta/Benelli has not provided the public with information on how to tell the Benelli choke types apart, nor which gun models use which choke type. Even the names of Benelli's tube types are confusing - Trulock, which makes some of the tubes for Benelli, uses a name that Benelli USA does not use on its web site. The result of all this is mass confusion about which tubes can be interchanged.
Of course it has been known for a long time that the Benelli "Standard" tubes that were used for years are identical to Beretta's MobilChoke tubes, and can be safely interchanged. In fact, some aftermarket tube manufacturers label these tubes BER/BEN to indicate that they are for either Beretta or Benelli guns. Now that Beretta has Optima and Optima Plus tubes, and Benelli has a couple of similar tube types, some people are trying to interchange them. I do not recommend that unless you first get a gunsmith to check and make sure that the particular switch you want to make is safe, and measure the bore and choke diameters to determine the degree of choke you will get if you make that switch.
The fact that some Beretta tubes will screw into some Benelli barrels and vice versa does not mean that they can be correctly interchanged. The bores of the Beretta and Benelli guns do not have the same diameter, so switching the tubes will result in a degree of choke that is different from what is marked on the tube. More importantly, you should not assume that the tube seats correctly at the skirt nor that a sufficient length of threaded section engages to hold the tube in place. It is possible for some of these tube types (even within the same brand) to screw in place but leave a section of the tube outside the barrel. Shooting a gun that way could result in damage to the tube and/or the barrel, and is potentially dangerous to bystanders.
Maybe someday Beretta/Benelli will tell us clearly which tube types can be safely interchanged, but don't hold your breath until it happens. In the meantime, don't do it without getting it checked out by a gunsmith first.
Thanks to Worc for helping with the picture.
There is a fourth choke tube type that was used on a few of the first guns Beretta made with choke tubes. The tube itself has no threads on it, but it is held in place by a collar that screws onto threads on the outside of the barrel.
A warning about interchanging tube types.
Beretta has created a confusing situation with the use of three different choke tube systems (four, counting the old drop-in, collared type). It gets even more confusing when you consider Benelli choke tubes. Benelli is owned by Beretta, and they have recently brought out several choke tube types that appear similar to the Beretta Optima and Optima Plus tubes, but are designed to be used with a bore diameter that is different from the Beretta Optima bore. To make matters worse, as far as I can determine Beretta/Benelli has not provided the public with information on how to tell the Benelli choke types apart, nor which gun models use which choke type. Even the names of Benelli's tube types are confusing - Trulock, which makes some of the tubes for Benelli, uses a name that Benelli USA does not use on its web site. The result of all this is mass confusion about which tubes can be interchanged.
Of course it has been known for a long time that the Benelli "Standard" tubes that were used for years are identical to Beretta's MobilChoke tubes, and can be safely interchanged. In fact, some aftermarket tube manufacturers label these tubes BER/BEN to indicate that they are for either Beretta or Benelli guns. Now that Beretta has Optima and Optima Plus tubes, and Benelli has a couple of similar tube types, some people are trying to interchange them. I do not recommend that unless you first get a gunsmith to check and make sure that the particular switch you want to make is safe, and measure the bore and choke diameters to determine the degree of choke you will get if you make that switch.
The fact that some Beretta tubes will screw into some Benelli barrels and vice versa does not mean that they can be correctly interchanged. The bores of the Beretta and Benelli guns do not have the same diameter, so switching the tubes will result in a degree of choke that is different from what is marked on the tube. More importantly, you should not assume that the tube seats correctly at the skirt nor that a sufficient length of threaded section engages to hold the tube in place. It is possible for some of these tube types (even within the same brand) to screw in place but leave a section of the tube outside the barrel. Shooting a gun that way could result in damage to the tube and/or the barrel, and is potentially dangerous to bystanders.
Maybe someday Beretta/Benelli will tell us clearly which tube types can be safely interchanged, but don't hold your breath until it happens. In the meantime, don't do it without getting it checked out by a gunsmith first.