Glock has begun a program to replace the recoil spring assembly (RSA) for Glock Gen4 pistols. If you send in your recoil spring, they will send you back a replacement. They have not specified exactly what was wrong with the previous RSA design.

GLOCK ANNOUNCES VOLUNTARY REPLACEMENT OF RECOIL SPRING ASSEMBLIES IN GEN4 PISTOLS
Replacement Program Limited to Gen4 Model with GLOCK Covering All Shipping Expenses

SMYRNA, GA – September 7, 2011 – GLOCK Inc. announces that it is voluntarily exchanging the recoil spring assembly (RSA) on its new Gen4 pistols shipped since August, 2009, to ensure each pistol’s performance meets the company’s demanding standards. With several variations of the RSA in the market today, GLOCK’s goal with this voluntary exchange is to standardize the RSA to gain the best possible performance in each pistol.

GLOCK’s product development team has modified various elements of the RSA. The new RSA compensates for all design modifications made to the Gen4 and allows the pistols to function up to GLOCK’s rigid quality standards and reliability goals.

Consumers should note that Gen4 G26 and G27 models will not require a modified recoil spring.

“We are moving proactively and quickly to standardize this part of the pistol. This is a voluntary exchange specifically for the new Gen4 models,” said Gary Fletcher Vice President GLOCK Inc. “We have developed a program for consumers to send in their existing recoil spring assemblies and receive new ones at no cost.”

The replacement of the Gen4 pistol RSA can be performed as part of the regular field-strip process; consumers do not need to take the Gen4 pistol to an armorer. Consumer’s wishing to participate in the exchange program are urged to call 1-877-745-8523 to order their new recoil spring.

For more information on the details and shipping requirements on the replacement program, visit www.teamGLOCK.com.

UPDATE: I posted an image of the wrong spring. A chart of recoil springs is at Guns, Holsters & Gear.