Those who take advantage of SIG’s recently announced “voluntary upgrade” may soon be taking home a little piece of the Modular Handgun System program: The company evidently plans to introduce a new trigger design developed for the MHS program as part of the upgrades, as relayed in a recent article published by Eric Graves over at Soldier Systems Daily:

While the MHS passed DoD’s TOP 3-2-045 test with the trigger currently in the commercial P320, SIG proposed an enhanced trigger via Engineering Change Request E0005. As it didn’t result in additional cost to the government and only improved the firearm’s performance, M17s currently being delivered to the US Army have this trigger. Additionally, this trigger also eliminates the “double click” felt during P320 trigger pull.

Although SIG was already working toward introducing the MHS-inspired Enhanced Trigger to the P320, this -30deg drop issue has hastened their effort. They have lightened the Trigger, Striker and Sear by about 30% overall and added a Disconnect (commercial only, not MHS). The trigger pull weight is unaffected, but rather the trigger part actually weighs less. The reason they lightened those parts is to mitigate the momentum gained by the heavier parts during a drop.

Taylor laid it out, “There is a vulnerability with the P320 at the -30deg drop.” They plan to incorporate the trigger enhancements for the M17 into the P320. They’d been working on them, but implementation wasn’t imminent. Based on what they’ve found, that has been accelerated. Details on their voluntary upgrade program will follow soon.

I recommend our readers click through to read the whole thing. It’s quite interesting.

The “voluntary upgrade” comes in the wake of the discovery of a malfunction with the P320 handgun, where the weapon can fire when dropped at certain attitudes. As far as is known, this malfunction is due to the inertia of the trigger carrying it to the rear under an impact. This malfunction is usually prevented in striker-fired handguns via the inclusion of a so-called “dingus” on the trigger, which prevents trigger movement until the lightweight dingus is depressed, unlocking the trigger. There is also evidence that this malfunction can occur without movement of the trigger somehow, as demonstrated in a test by TFB’s Patrick R. In this test, the pistol fires when struck by a hammer, without significant trigger movement. It remains to be seen whether SIG’s fix using the MHS trigger pack will completely solve the issue or not.