A lightened bolt catch spring for AR15 .22 last round magazine hold open bolt catches.
S&W M&P 15-22 magazines feature chunky box springs providing plenty of strength to reliably operate regular AR15 .22 lock backs, but other magazines featuring push up mechanisms with lighter coil springs can sometimes run into lock back activation problems.
- Kriss defiance DMK 22 magazine
- Black Dog Gen III 32 round magazine
By replacing a standard weight AR15 pocket spring with this specially lightened version these magazines work much more reliably.
Designed to work with .22 bolt release catches:
- Catch22 AR15 .22 bolt release catch upgrade
- Kriss defiance bolt release mechanism