We recommend stretching your stock springs when installing our extensions. Please watch install video in the description of the parts. However sometimes the factory springs will have a shorter stretch. The stock springs will compress back down to original stretch over time. These extra coil springs will keep better spring tension in the 141mm USPSA mag extension length. ( Our longer extensions +3 - +6)
These are an extra coil spring for use ONLY with our M&P 9mm/.40 +6 extension, 10mm +3 (does NOT work with .45 mags)
If you are having issues with spring tension.
If your slide is not locking back on the last round.
Please note these are not needed in all magazines.
Wolff extra coil springs are designed M&P. (These are Extra Coil "length" NOT the +10% power springs sold on their website)
Not eligible for return. Limited Warranty through Wolff Springs. Details on packaging
Not eligible for discount codes.
SHIPPING INFO - We use USPS small flat rate box. In order to protect the spring we are choosing to ship in a box instead of a cheaper way in an envelope. We do not like having to charge so much for shipping, but it is the best and cheapest option we have while doing our best to protect your order. Free shipping is available for parts orders over $100.