Customer Supplied Magazines:

In addition to offering new CST Modified magazines both individually and with the Auto-Bolt Stop Kits, CST will be happy to modify your existing Ruger magazines. This can be a very affordable option for any extra Ruger magazines you may have on hand. Also remember, as with new modified magazines, once your magazines are modified they will still function fine in any 10/22, with or without an auto-bolt stop installed.

The warranty covers a new modified magazine as well as a modified customer supplied magazine, as long as the supplied magazine is found to be free of defects. Every CST Modified Magazine, new or customer supplied, has been identified by "CST MOD MAG" stamped clearly on the bottom of the magazine. Using unmodified magazines or anything else won't work and voids the warranty.

In addition to the standard (BX-1) .22LR magazines, CST will also modify the Ruger 40th Anniversary and 5-round magazines. The Ruger 77/22 magazines are not compatible with the 10/22 and should not be used or modified.


All CST Modified Magazines are completely disassembled and rebuilt in 6 steps:

  1. If the magazine gets inspected and completely cleaned.
  2. The magazine throat has the necessary clearance cut CNC machined in place and then it is completely deburred and polished.
  3. A clearance cut is also cut in the rear plastic plate and then it is completely deburred, including the common burrs left from the factory underneath the hex nut.
  4. The socket head screw is carefully turned in a lathe and 100% inspected for correct height. It is then deburred and reblued.
  5. The magazine body is stamped to identify it as an authentic CST Modified Magazine.
  6. Each magazine is then reassembled with the correct spring tension on the follower (2 to 2 1/2 turns) and properly snugged for reliable function.

Customer supplied magazines can be modified for $10.95 each plus shipping.