INTRODUCTION

The history and development of the US Army’s Grenadier Sighting System is a remarkable story spanning many years, resulting in a sighting system that is unmatched for this type of small arm. The Wilcox Grenadier Sighting System (GSS) day/night sighting system for the M320/ M320A1 grenade launcher (GL) is the result of over a decade of design refinement, development, developmental testing, operational testing, lessons learned, continuous improvement, and ongoing production in conjunction with the US Army; it is simply the most accurate, user-friendly, forward-upgradeable, and most heavily tested day/night sighting system for the M320/M320A1 GL in the world.

Also, based on the capability of the GSS to download and select from a multitude of ballistic data tables, it can be easily programmed with relevant ballistic data table(s) to accurately work with other portable 40mm GLs. Wilcox has been designing and developing day/night sights for the Department of Defense and friendly foreign nations for over 25 years. This modern-day story picks up from when the US Army started replacing the M203 GL and fielding the M320 GL.

US ARMY STARTS FIELDING NEW 40MM M320 GRENADE LAUNCHER

In 2009, the US Army started fielding a newly selected 40mm grenade launcher to replace all existing M203 GLs. This newly selected GL was designed, developed, and initially produced by Heckler & Koch (H&K). The Technical Data Package was licensed to the US Government for its use and type, designated by the US Army as the M320/M320A1 GL variants.

While the new M320 GL came with a simple mechanical leaf sight with 50-meter (m) aiming increments up to 350m for day use, it did not take long for the US Army to begin the search for an improved day/night sight. There was a different barrel length and muzzle velocity for the same ammunition, as well as other differences between the current M320/320A1 GL and the former M203 GL. This meant users employing M203 ballistic trajectory data tables from previously fielded sights for various 40mm ammunition rounds were inherently inaccurate from the moment the round exited the M320 GL muzzle; this inaccuracy grows larger with increasing target range. This was true for the most sophisticated M203 day/ night sights at that time. The idea of simply using older M203 sights not designed for the M320 GL was unacceptable to the Army. Especially when responsible parties within the Army knew a more accurate, more versatile, and overall faster engaging day/night sight could be acquired, which would increase soldier mobility, lethality, and survivability.

Also, the US Army engineers knew and had the test data to show the same ammunition has different ballistic trajectory data dependent on whether the M320/320A1 GL was used in standalone, underslung with M16 Rifle or underslung with a M41A1 Carbine. To this point, as you will learn, ultimately the GSS would be preloaded with US Army ammunition ballistic tables for the M781 Target Practice (TP) and M433 High Explosive Dual Purpose (HEDP) for each of the three three aforementioned weapon configurations. The same ammunition has meaningfully different ammunition ballistic data tables for each weapon configuration for increased accuracy.

All of these essential calculations for increasing GSS accuracy will be done internally, the user would simply set the sight to the desired range and preselect the weapon/ ammunition configuration. To make it easier for users, the Army’s threshold will require a quick selection switch, so users can rapidly select between two preselected weapon/ ammunition configurations, seen in the rear of the GSS as “Ammo 1” and “Ammo 2.” This way, users can preset weapon/ammunition configurations for enhanced accuracy, speed of change, and ease of use purposes. Other preloaded weapon/ammunition ballistic data tables will be available through the onboard menu selection and display for current and future 40mm ammunition. Back to the case study history and unfolding events.

INITIAL COTS DAY/NIGHT SIGHTS FOR M320/320A1 GL DEEMED UNSUITABLE

In 2009, the US Army issued a request for information seeking commercial sources for a new day/night sight with an integrated laser rangefinder specifically for use with the M320 GL. The US Army sought Commercial Off the Shelf (COTS) products that met its product met its product description. Subsequently, the US Army conducted a series of tests of acquired candidate’s product samples for its Grenade Launcher Rangefinder (GLRF) program in the 2010–2011 time period. The COTS offering was ranked and down-selected to two (2) candidates. Ultimately, the top-ranked GLRF COTS offering was found to be too heavy and large for effective use on the M320/320A1 GL by US Army soldier representatives. After determining a COTS solution was not going to adequately meet user requirements and needs, US Army material and capability developers jointly reassessed the approach.

APPLICATION OF LESSONS LEARNED TO DEVELOP & SELECT THE GSS

The US Army user representatives/capability developers issued a refined requirement, which removed the integrated laser rangefinder. Rather than using a COTS approach, the US Army product management and technical team developed a comprehensive program plan and product description in conjunction with user-representative capability developers. This included a multi-stage Development Effort for extensive developmental/operational testing to be followed by a Production Effort, all under the same US Army contracting effort.

The US Army engaged with Industry continuously to consider Industry inputs to a future competitive program plan. From 2012-2015, the US Army engaged with Industry publicly with no less than five (5) market surveys for Industry Response, two (2) Industry Days, and two (2) draft Request for Proposals for comment.

The GSS contractor would be responsible for Developmental Engineering, which would leverage initial candidate product samples with related improvements. The purpose is to provide test and evaluation support and manufacture prototype units to support testing and evaluation for this developmental effort.

As part of the US Army’s final Request for Proposal, the GSS developmental effort was broken into two (2) phases:

• Phase I – Candidate System Design and Evaluation

• Phase II – Developmental and Engineering Prototype Design and Evaluation.

Contractors were afforded the opportunity to modify developmental GSS hardware at various points of the program plan based on written test results and Soldier feedback. The US Army was determined to ensure the program resulted in an effective GSS, which Soldiers wanted to carry and employ with their M320/M320A1 GL. The historical milestones are broken down as follows. In June 2015, the US Army issued its extensive GSS Request for Proposal. By August 2015, competitive offerers provided proposal responses and product samples. In April 2016, the US Army made two competitive awards with the intent of down-selecting a single production awardee. After three years of extensive development, testing, and evaluation in a competitive environment, the US Army chose the Wilcox GSS as the single production awardee in June 2019.

The history of the US Army’s Grenadier Sighting System (GSS) is a remarkable story that exemplifies a successful program collaboration between the US Army and the Wilcox Special Projects Team. The Wilcox Grenadier Sighting System day/night sighting system for the M320/M320A1 grenade launcher is the result of over a decade of design refinement, development, testing, continuous improvement, and ongoing production in conjunction with the US Army; it is simply the most accurate, user-friendly, forward-upgradeable day/night sight for the M320/M320A1 GL in the world.

Learn more about the Development of the Wilcox Grenadier Sighting System or download the GSS Case Study.