Trinity Trigger MP5 3-Position FRT

The Trinity Trigger MP5 3-Position FRT is the build-it-yourself path to MP5 forced reset, and the cheapest entry into the category if you already run, or plan to run, an AR fire control group inside an MP5-pattern lower. It is not a complete lower like the Mars or Rare Breed units. Trinity is explicit that it requires an AR-15 FCG lower adapted to the MP5 platform and does not function in a stock MP5 lower, so it pairs with an AR-FCG MP5 lower from Leber, AS Designs, or a similar maker rather than dropping into a factory housing.

The kit ships the components that convert that AR-FCG lower to forced reset: a V3 Trip Kit, a trigger (curved or flat), a cam, a lever, a curved detent, and an M16 spacer. The third position on the selector engages forced reset, where the bolt carrier mechanically resets the trigger after each shot. Parts are 4140 heat-treated steel and made in Texas. Trinity sells per-clone housings, so the catalog covers the AP5 and AP5-P families, MAC5K, ZF5K, POF5K, and the HK SP5 and SP5K.

Pricing runs from $199.99 to $529.95 depending on which trigger and configuration you select, which makes the entry point roughly a third of a complete Mars or Rare Breed unit. The trade is assembly: you supply or build the AR-FCG lower and install the trip kit yourself rather than pushing two pins on a finished lower. It is direct-only from Trinity. Verify current federal, state, and local law before purchase.