Welcome to Modern Defense Systems, LLC

FFL/SOT, Firearms Manufacturing, NRA & MA State Police Certified Training, Certified Glock Armorer Services, & Consulting

(781) 214-1015


MDS Machine & Tool Division Class 3 Manufacturing

We offer custom Class 3 Manufacturing services to LE/Govt organizations who desire custom rifles for duty use. We offer an wide selection of M16, M4, and MP5 variants to suit your needs. Ask about other platforms as well.

Massachusetts LTC/FID Approved Training

Our basic firearm training course is approved by the MA State Police and qualifies LTC/FID Card applicants. Learn about Gun Safety & Massachusetts Firearm Laws

Glock Armorer Services

We offer Certified Glock Armorer Services to keep your firearm functioning and in top shape.

About Us


  • NRA & Mass State Police Certified Instructor (Home Firearm Safety & Pistol)
  • Glock Certified Armorer
  • NRA Personal Protection Inside The Home Graduate
  • Carbine I Graduate- TacDynamics
  • VCAT/Officer Down Training Graduate- TacDynamics
  • Lifelong Hunter & Shooter

High-Quality Equipment

We work with some of the world's leading manufacturers including:

  • Anderson Manufacturing
  • CMMG
  • Dakota Tactical
  • Double Star Tactical
  • Glock
  • LMT-Lewis Machine & Tool
  • Liberty Supressors
  • Stag Arms
  • Yankee Hill Machine


 VCAT Tactics & Officer Down Training Course

We have partnered with the outstanding team from Tactical Dynamics to offer an amazing array of advanced training courses.

Featured Products

New products are coming soon!

Contact us for inventory inquiries.

Contact Us

Send us a message

Modern Defense Systems LLC

Randolph, MA 02368

(781) 214-1015



8:00 am – 5:00 pm


8:00 am – 5:00 pm


8:00 am – 5:00 pm


8:00 am – 5:00 pm


8:00 am – 5:00 pm


8:00 am – 2:00 pm



By Appointment Only


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