The A-Bolt was built in two main series. The original A-Bolt and the A-Bolt II. Both are very similar rifles and are considered part of a design family. The new AB3 — sometimes also referred to as an A-Bolt — is a different model and design. Accessories, such as bases and rings, magazines, etc. made for the original A-Bolt and A-Bolt II will not fit the AB3. All three of these designs are totally separate from the X-Bolt rifle as well. 

To identify which rifle you have, you will either need to 1) know the serial number or 2) answer a few questions about the rifle. In a few seconds, you can easily determine what Browning rifle it is.

Locate the serial number and identify the last three digits. They represent the following rifles:

• 351 is an A-Bolt II or I (original A-Bolt)
• 358 is the AB3
• 354 is an X-Bolt

Just look closely at the rifle in front of you and you will know what it is right away by asking this:

• Is there a hinged floor plate or does the magazine pop right into you hand?
  • AB3 drops out, A-Bolt II (and original A-Bolt) is attached to the floorplate

• Is the magazine release in front or behind the magazine?
  • Next to trigger guard is A-Bolt II (or original A-Bolt), in front is AB3

• Is the magazine plastic or metal or a combination of the two?
  • All metal is A-Bolt II (or original A-Bolt), plastic and metal is AB3

• Is the bolt body in the ejection port round or are there flats?
  • If it is round it is an AB3, If it has flats it is an A-Bolt II (or original A-Bolt)

The A-Bolt shotgun is a unique design incorporating many of the design features of the original A-Bolt and the A-Bolt II rifle. However, it is simply an A-Bolt Shotgun -- a unique product. Conveniently, it does have the same scope base attachment screw setup as the A-Bolt II and general features and benefits are similar (short bolt lift, detachable magazine with hinged floorplate, etc.). 

Occasionally someone might not know how to identify the X-Bolt. Just remember that each scope base is held down by four screws -- four at the front and four at the back. If it takes eight screws to mount the bases, it is an X-Bolt. It also features a larger, curved bottom metal surrounding the magazine well which is not only elegant, but easy to identify as on an X-Bolt.