OK I am new here and looking to get a S&W snub nose. What is the difference between the 340, 442, 638, 640, and 642? Thsy are all J Frame.

They are all "J" frame. The differences are either in the metals used or in the hammer design. Go to S&W site and take a close look at each model's hammer. Some are exposed. The 638 hammer is concealed with a shroud but you can still operate the hammer by hand while the 640 has a shroud but you cannot get to the hammer. The object here is to give the buyer choices for concealed carry like in a pocket where with no adjustable sights and no exposed hammer it will not get caught when being withdrawn.

I hope that helps answer your question.

The 340 is the lightest and most expensive. It’s chambered in .357 Magnum, has an internal hammer (DAO), a titanium cylinder and an aluminum/scandium alloy frame. The 442 is a similar gun chambered in .38 Special with a carbon steel barrel and cylinder and an aluminum alloy frame. It’s the least expensive of those you mentioned. The 642 is identical to the 442, except the cylinder and barrel are stainless steel. The 638 is like the 642, except it has a shrouded hammer that can be cocked for single action shooting. The current 640 is an all stainless DAO (internal hammer) .357 Magnum that’s substantially heavier then any of the others mentioned.

Welcome!

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