Unfortunately, it's been three years since I have purchased anything from them. Two 300 BO barrels, two gas tubes and two gas blocks. The customer service (basically online order and shipping to me) was fine. There address via google search is listed as: 658 Griffith Rd #111. Charlotte, NC 28217.18" .223 WYLDE AR-15 BARRELED UPPER - MAS DEFENSE NERO 15" M-LOK RAIL - BALLISTIC ADVANTAGE BARREL SALE PRICE: $295.99 ... cant ask for anything more and will happily purchase again from MAS defense. Was this review helpful to you? 0 of 0 people found the following review helpful:16" 5.56 / .223 AR-15 1X8 FAXON FIREARMS GOVT / SOCOM PROFILE MID-LENGTH BARREL - 15A58M16NSQ. Faxon Firearms barrels are the pinnacle of value. Manufactured 100% in-house from cradle-to-grave, these barrels are fully stress relieved, air-gauge tested, and 11 degree target crowned to ensure superior accuracy. Quality is imbued into our …MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer with Quality Parts at Reasonable Prices! Our foundation is built on excellent customer service, honesty and integrity.30 Jun 2022 ... Comments81 · The Backpack Gun Project · Everything About Truck Guns · Faxon 6" 300 BLK AR15 Barrel Review (1:5 Twist) · MAS Defense...2. Barrel - 5.25" 9MM NATO (9x19) 1x10 4150 CrMoV Melonite Nitride Treated Steel. 3. Handguard - MAS Defense "NERO" 4.2" Slimline M-LOK Free Floating Handguard - (ID 1.25") 4. Muzzle Device - A2 Half Cage. Bolt Carrier Groups and Charging Handles are sold separately. All barreled uppers are head spaced and test fired to ensure function.MAS DEFENSE 10.5" 223 WYLDE 5.56 Barreled Upper for an AR15 pistol build.MPN: P80-BKSS-BLK. Polymer80 presents the BKSS™ 80% Subcompact Single Stack Frame. Offering compatibility with Glock® 43 Gen4 components, the PF9SS™ frame comes with an aggressive texture that emulates a stippled pattern, an extended beaver tail, double undercut trigger guard, and a thumb ledge. These features considerably enhance the ...Are you a savvy shopper looking for unbeatable deals on home goods and furniture? Look no further than the Habitat Warehouse Sale in Sharon, MA. This highly anticipated event offer...I highly recommend the Vector rail and end cap and MAS Defense fast shipping. Was this review helpful to you? 0 of 0 people found the following review helpful: Really ties the build together: ... Enter your email address for special offers from MAS Defense LLC. 8334 Pineville Matthews Rd Ste 103 #254 Charlotte, NC 28226 [email protected] Defense Supply is a division of Mas Industrial Supply LLC, which specializes in serving the defense industry and supplying critically important products. We are proud of the trust we add to human and social life by supplying high security class products needed by the defense industry with its expert staff and proven quality products and ...6 Apr 2022 ... Deadly Force in Self-Defense: What You Need to Know - Critical Mas(s) Ep. ... Randy Reviews It•170K views ... S&W M&P FPC 9mm Folding Carbine Full ...MPN: P80-NKIT-FDE. The Polymer80, Phoenix2, AR15 80% Lower and Jig System is designed as a complete kit. There's NO expensive jig kits and parts to purchase - the system is a COMPLETE, all inclusive package in one price! The Phoenix, Gen2 version features Polymer80's proprietary polymer composite, a solid core design, stiffened …When it comes to managing your energy costs, understanding the various tariffs offered by National Grid MA is crucial. These tariffs determine the rates you pay for electricity and...On February 23, 2024, Sen. Warren and Rep. John Garamendi (D-CA 8th District) sent a letter to the Secretary of Defense, expressing concerns about how the …Are you searching for properties in Randolph, MA? Look no further than 128 York Ave. This article will provide you with a complete guide on finding properties on this sought-after ...6 Apr 2022 ... Deadly Force in Self-Defense: What You Need to Know - Critical Mas(s) Ep. ... Randy Reviews It•170K views ... S&W M&P FPC 9mm Folding Carbine Full ...10 Dec 2019 ... Log in · Sign up. Conversation. MAS DEFENSE · @MASDefense. Image. 3:48 AM · Dec 10, 2019.Are you in the market for a new home in West Roxbury, MA? With its charming neighborhoods, convenient location, and strong sense of community, it’s no wonder why many people are lo...Shoot us a e-mail to [email protected] to discuss your plans. We look forward to serving you! MAS Defense is an AR-15, AR-10 and Glock parts store. We are …7 May 2023 ... ... Carry Revolvers for 2023. MadMan Review•475K views · 17:02 · Go to channel · Deadly Force in Self-Defense: What You Need to Know - Critical ...10.5' 300 BLACKOUT BARRELED UPPER - MAS NERO 9.87' M-LOK RAIL. A4 Forged Upper Receiver. 4150 CMV Nitride or 416R Stainless Steel Barrel. M4 Ramps. MAS Defense Nero 9.87' M-LOK Handguard. .750 Low Profile Steel Melonite Gas Block. Pistol Gas System.This device is designed to direct gasses and noise forward away from the shooter. The inside bore is drilled out in the form of a funnel eliminating the need for extra pieces. 6061 Aluminum. Solid One Piece Construction. Anodized Finish. Measures 3.25" x 1.20". 1/2 x 28 Thread - 5.56 / .223. Weight 3oz. MPN: MAS0002202. The MAS Defense Complete 80% Jig Kit is all you need to complete the final machining process on your 80% AR-15 and AR-9 receiver. Includes: - Aluminum side plates with steel bushings. - Three top plate templates. - All necessary hardware. - Made In the USA. MAS Defense AR15 Slick Side Upper Receiver. No forward assist or ejection door capabilities. Forged From High-Grade 7075 T6 Aluminum. M4 Feed Ramps. No T-Marks. Black Hardcoat Anodized Mil-Std-171 Type III. mas defense 9mm 416r stainless steel barrel - glock 19 fitment - matte gray pvd - threaded MAS DEFENSE 9MM 416R STAINLESS STEEL BARREL - GLOCK 19 FITMENT - MELONITE NITRIDE Our Price : $119.99 MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer with Quality Parts at Reasonable Prices! Our foundation is built on excellent customer service, honesty and integrity. by David Crane defrev (at) gmail (dot) com August 13, 2004 DefenseReview did not receive any of the information contained in the first two paragraphs of this story from Le Mas Ltd., or from Stan Bulmer. Le Mas/Stan Bulmer will not discuss military operational use of, or field performance data relating to, the Blended Metal Technology (BMT) or BMT APLP (Armor-Piercing Limited-Penetration ...VECTOR 15" FREE FLOAT QUAD RAIL. View Larger Photo Email A Friend. MSRP: $75.00. Our Price: $64.99. Stock Status: (Out of Stock) Product Code: HG-VQRER.MSRP: $149.00. Our Price: $129.99. SALE PRICE: $69.99. In Stock. (63) MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer …MPN: P80-NKIT-BLK. The Polymer80, Phoenix2, AR15 80% Lower and Jig System is designed as a complete kit. There's NO expensive jig kits and parts to purchase - the system is a COMPLETE, all inclusive package in one price! The Phoenix, Gen2 version features Polymer80's proprietary polymer composite, a solid core design, stiffened …MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer with Quality Parts at Reasonable Prices! Our foundation is built on excellent customer service, honesty and integrity.MAS Defense: .300 BLK Lower Review. I got my .300 blk lower from MAS defense and I wanted to just give a little review/ comparison of the budget vs high end. I …MAS DEFENSE 9.87" SQUADRON LIGHTWEIGHT QUAD RAIL - BLACK. Proudly Made In The USA. Our "SQUADRON" quad rail with lightweight cuts make it feel as it it's floating on air. It is machined from 6061 aluminum and anodized with a Type III Class 2 Hardcoat. The rail itself weighs in at 11oz. Add the barrel nut and attaching screws for a total of 13oz. MPN: MAG417-BLK. The MOE Trigger Guard (Magpul Original Equipment) is an enhanced polymer drop in replacement for the AR15/M4 weapons platform. It features a shallow "V" shape for better use of gloves in tactical shooting or cold weather operations. The MOE Trigger Guard is non-folding, has rounded edges, and fills the annoying "gap" at the ... Dec 18, 2022 · MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer with Quality Parts at Reasonable Prices! Our foundation is built on excellent customer service, honesty and integrity. MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer with Quality Parts at Reasonable Prices! Our foundation is built on excellent customer service, honesty and integrity.Barrel - 8.5" - 9.5" 300 Blackout Barrel. Click on the drop down box above to choose from our selection. 3. Handguard - MAS Defense "RIDGELINE" 9.87" Slimline M-LOK Free Floating Handguard - (ID 1.25") 4. Gas Block - .750 Low Profile Steel Melonite Nitride Treated Gas Block. 5. Gas Tube - Pistol Length Stainless Steel Gas Tube.MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer with Quality Parts at Reasonable Prices! Our foundation is built on … MAS DEFENSE 80% LOWER COMPLETION JIG AR-15 / AR-9 MPN: MAS0002202 The MAS Defense Complete 80% Jig Kit is all you need to complete the final machining process on your 80% AR-15 and AR-9 receiver. Includes: - Aluminum side plates with steel bushings - Three top plate templates - All necessary hardware - Made In the USA Drill Bits Needed: mas defense 15" nero m-lok free float - black 16" 300 blackout ar-15 barreled upper - mas defense nero 12.62" m-lok rail 16" 5.56 / .223 ar-15 barreled upper - mas defense nero 15" m-lok rail - mid length gas lower parts kit mil-spec ar-15 - minus fire control group - gripAre you searching for properties in Randolph, MA? Look no further than 128 York Ave. This article will provide you with a complete guide on finding properties on this sought-after ...MPN: MAS0002202. The MAS Defense Complete 80% Jig Kit is all you need to complete the final machining process on your 80% AR-15 and AR-9 receiver. Includes: - Aluminum side plates with steel bushings. - Three top plate templates. - All necessary hardware. - Made In the USA. The Magpul MOE Stock – Mil-Spec Model is a drop-in replacement buttstock for AR15/M16 carbines using mil-spec sized receiver extension tubes. Designed for light, fast action the streamlined A-frame profile avoids snagging and shields the release latch to prevent accidental activation. MAS Defense Uppers. Thread starter neal007; Start date May 29, 2014; Forums. The Hide Armory. Semi-Automatic Rifles . N. neal007 Private. Full Member. Minuteman. Feb ...Mas Defense Supply is a division of Mas Industrial Supply LLC, which specializes in serving the defense industry and supplying critically important products. We are proud of the trust we add to human and social life by supplying high security class products needed by the defense industry with its expert staff and proven quality products and ...razzlee21. • 10 yr. ago. I had a very good experience with MAS Defense. Very quick turn around from order to delivery. My shipping address and payment address were different so they required a phone call. Got through in three rings and had a pleasant conversation. I will be buying from them, again.Best AR-15 Bolt Carrier Groups (BCG) 1. Bravo Company Manufacturing (BCM) M16 BCG. Let’s just start with our editor’s pick for a branded mil-spec BCG. If you ask most people online what’s their go-to BCG…the vast majority is going to be BCM’s M16 BCG. BCM M16 BCG.30 Oct 2023 ... Go to channel · Deadly Force in Self-Defense: What You Need to Know - Critical Mas(s) Ep. 03 with Massad Ayoob. Wilson Combat•920K views · 25:21. Location of This Business. 8334 Pineville Matthews Rd Ste 103 PMB 254, Charlotte, NC 28226-3764. BBB File Opened: 5/3/2024. Business Incorporated: 6/7/2013. Type of Entity: Limited Liability ... 16" 300 BLACKOUT AR-15 BARRELED UPPER - MAS DEFENSE NERO 12.62" M-LOK RAIL MAS DEFENSE 15" NERO M-LOK FREE FLOAT - BLACK AR-15 BOLT CARRIER GROUP 5.56 & 300 BLACKOUT BCG - MELONITE NITRIDE ... Was this review helpful to you? 0 of 0 people found the following review helpful: Hybrid polished chrome BCG: …Jun 13, 2020 · MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer with Quality Parts at Reasonable Prices! Our foundation is built on excellent customer service, honesty and integrity. On February 23, 2024, Sen. Warren and Rep. John Garamendi (D-CA 8th District) sent a letter to the Secretary of Defense, expressing concerns about how the …18" .223 WYLDE AR-15 BARRELED UPPER - MAS DEFENSE NERO 15" M-LOK RAIL - BALLISTIC ADVANTAGE BARREL SALE PRICE: $295.99 ... cant ask for anything more and will happily purchase again from MAS defense. Was this review helpful to you? 0 of 0 people found the following review helpful: This complete 80% jig kit is all you need to complete the final machining process to turn your 80% AR-15 Receiver into a working stripped lower receiver. Includes: Left and Right side fixture plates / vice jaws. Three top plate templates. All hardware necessary to secure jig and top plate. POLYMER80 80% PISTOL FRAME KIT WITH JIG SUB-COMPACT G26 / G27 PF940SC P80-PF940SC-FDE - FLAT DARK EARTH + JIG Glock 26 Glock 27 P80AR-15 UPPER PARTS. >. AR-15 GAS BLOCKS / TUBES. >. GAS BLOCK ASSEMBLY FIXTURE - EASY ROLL PIN INSTALLATION WITH PUNCH. Installing gas block roll pins has never been easier! This jig allows you to hold the gas block in place while inserting the roll pin. Without the fixture I destroyed two roll pins and marred up my gas block and gas …Barrel - 8.5" - 9.5" 300 Blackout Barrel. Click on the drop down box above to choose from our selection. 3. Handguard - MAS Defense "RIDGELINE" 9.87" Slimline M-LOK Free Floating Handguard - (ID 1.25") 4. Gas Block - .750 Low Profile Steel Melonite Nitride Treated Gas Block. 5. Gas Tube - Pistol Length Stainless Steel Gas Tube.18 Feb 2024 ... ... reviews for the PEOPLE, not the industry? Make sure ... Defense With Doug Marcaida and Tomas Alas ... Mas Episode 17. Wilson Combat•1.1M views · 21 ...MAS Defense: .300 BLK Lower Review. I got my .300 blk lower from MAS defense and I wanted to just give a little review/ comparison of the budget vs high end. I …Jul 4, 2023 · Best AR-15 Bolt Carrier Groups (BCG) 1. Bravo Company Manufacturing (BCM) M16 BCG. Let’s just start with our editor’s pick for a branded mil-spec BCG. If you ask most people online what’s their go-to BCG…the vast majority is going to be BCM’s M16 BCG. BCM M16 BCG. MAS DEFENSE RIOT 9MM MUZZLE BRAKE - MELONITE NITRIDE - 1/2x36 TPI. 1/2 x 36 TPI for 9MM. Installation without leaving tool marks. - Wrap the bag around the wrench flats at the end of the brake. - Place your wrench over the bag and brake. - Torque the brake down until the ports are at top dead center. Great quality!March 28, 2016. : Eric S. Couldn't be happier. Range d with the .300 BLK and Ozark Ordnance 147gr FMJ. Zeroed at 50yds and moved to 100yds using a 4 MOA dot optical sight with no magnification. All shooting inside the 4inch circle with my old eyes and I'm impressed. Function with my Olympic lower, full length stock and rifle buffer was flawless.13 Mar 2021 ... Remington model 512X Disassembly. Rusty Guns•13K views · 7:17. Go to channel · How To Buy A Home Defense Handgun. Colion Noir New 69K views · 1...MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer with Quality Parts at Reasonable Prices! Our foundation is built on excellent customer service, honesty and integrity.There's an issue and the page could not be loaded. Reload page. 6,467 Followers, 247 Following, 174 Posts - See Instagram photos and videos from MAS Defense (@masdefense)9" 300 BLACKOUT AR-15 1X8 FAXON FIREARMS MATCH SERIES 5R 416R PISTOL LENGTH BARREL - 15B38P9NGQ-5R-NP3. Faxon Firearms barrels are the pinnacle of value. Manufactured 100% in-house from cradle-to-grave, these barrels are fully stress relieved, air-gauge tested, and 11 degree target crowned to ensure superior accuracy.(SOLD OUT) MAS DEFENSE 4140 NITRIDE FRONT LOCKING BLOCK W/ P80 REAR RAIL & PINS [Add $62.99] *** ADD A JIG: Qty: E-MAIL ME WHEN BACK IN STOCK *** DESCRIPTION *** YOUR BILLING AND SHIPPING ADDRESSES MUST MATCH.*** ... Was this review helpful to you? 0 of 0 people found the following review helpful: Great …MAS Defense LLC is not and will not be held responsible for any city, county, state and/or federal laws that you (the purchaser) do not comply with. Due to the volatile nature and ever-changing laws regarding unfinished frames and lowers, these items are not returnable. ... Was this review helpful to you? 0 of 0 people found the following ...Are you a restaurant owner or a foodservice professional in the Chicopee, MA area? Look no further than Restaurant Depot. Located conveniently in Chicopee, MA, Restaurant Depot is ...MAS Defense LLC, Charlotte, North Carolina. 7,722 likes · 8 were here. AR-15, AR-10 and Glock Parts "Quality Parts at Reasonable Prices." MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer with Quality Parts at Reasonable Prices! Our foundation is built on excellent customer service, honesty and integrity. MAS Defense LLC is not and will not be held responsible for any city, county, state and/or federal laws that you (the purchaser) do not comply with. A 15% cancellation fee will be charged to orders containing this part with shipping addresses in the above outlined cities or states. Polymer80 handles all warranty claims directly. I asked here a while ago about mas defense uppers as they didn't have a lot of reviews anywhere. they had the 13.7" barrel I was looking for so I wanted to throw a quick hands on review for anyone else looking into them. 30 Jun 2022 ... Comments81 · The Backpack Gun Project · Everything About Truck Guns · Faxon 6" 300 BLK AR15 Barrel Review (1:5 Twist) · MAS Defense...Polymer80 presents the BKSS™ 80% Subcompact Single Stack Frame. Offering compatibility with Glock® 43 Gen4 components, the PF9SS™ frame comes with an aggressive texture that emulates a stippled pattern, an extended beaver tail, double undercut trigger guard, and a thumb ledge. These features considerably enhance the …18" .223 WYLDE AR-15 BARRELED UPPER - MAS DEFENSE NERO 15" M-LOK RAIL - BALLISTIC ADVANTAGE BARREL SALE PRICE: $295.99 ... cant ask for anything more and will happily purchase again from MAS defense. Was this review helpful to you? 0 of 0 people found the following review helpful:MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer with Quality Parts at Reasonable Prices! Our foundation is built on excellent customer service, honesty and integrity.AR-15 » Rifles, Uppers, Lowers, Barrels, and more. AR Sponsor: [ARCHIVED THREAD] - MAS Defense Barrels. ARCHIVED. Posted: 8/10/2017 7:06:12 AM EDT. Anyone have experience with or heard of MAS Defense? Looking at their 20" Spiral Fluted 223 Wylde Barrel, but never heard of the company.Jun 13, 2020 · MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer with Quality Parts at Reasonable Prices! Our foundation is built on excellent customer service, honesty and integrity. March 28, 2016. : Eric S. Couldn't be happier. Range d with the .300 BLK and Ozark Ordnance 147gr FMJ. Zeroed at 50yds and moved to 100yds using a 4 MOA dot optical sight with no magnification. All shooting inside the 4inch circle with my old eyes and I'm impressed. Function with my Olympic lower, full length stock and rifle buffer was flawless.
razzlee21. • 10 yr. ago. I had a very good experience with MAS Defense. Very quick turn around from order to delivery. My shipping address and payment address were different …. Terraces at forest springs
MAS Defense LLC is not and will not be held responsible for any city, county, state and/or federal laws that you (the purchaser) do not comply with. Due to the volatile nature and ever-changing laws regarding unfinished frames and lowers, these items are not returnable. ... Was this review helpful to you? 0 of 0 people found the following ...Are you searching for properties in Randolph, MA? Look no further than 128 York Ave. This article will provide you with a complete guide on finding properties on this sought-after ...Neither MAS Defense LLC, nor this site are affiliated in any manner with, or otherwise endorsed by, GLOCK, Inc. or GLOCK Ges.m.b.H. The use of “GLOCK” on this page is merely to advertise the sale of GLOCK pistols, parts, or components. ... Another solid product from MAS Defense! Was this review helpful to you? 0 of 0 people found the ... March 28, 2016. : Eric S. Couldn't be happier. Range d with the .300 BLK and Ozark Ordnance 147gr FMJ. Zeroed at 50yds and moved to 100yds using a 4 MOA dot optical sight with no magnification. All shooting inside the 4inch circle with my old eyes and I'm impressed. Function with my Olympic lower, full length stock and rifle buffer was flawless. This AR15 Upper Receiver comes with the ejection door already installed. This specific model does NOT have the ability to install a Forward Assist. Platform: AR15. M4 Feedramps. .250” takedown pin holes. Material: Machined from 7075-T6 forged aluminum. Coating: Anodized Black. Laser Engraved T-marks.MPN: P80-NKIT-FDE. The Polymer80, Phoenix2, AR15 80% Lower and Jig System is designed as a complete kit. There's NO expensive jig kits and parts to purchase - the system is a COMPLETE, all inclusive package in one price! The Phoenix, Gen2 version features Polymer80's proprietary polymer composite, a solid core design, stiffened … MPN: MAG417-BLK. The MOE Trigger Guard (Magpul Original Equipment) is an enhanced polymer drop in replacement for the AR15/M4 weapons platform. It features a shallow "V" shape for better use of gloves in tactical shooting or cold weather operations. The MOE Trigger Guard is non-folding, has rounded edges, and fills the annoying "gap" at the ... Black Hardcoat Anodized Mil-Std-171 Type III. M4 Ramps, Forward Assist, Ejection Door. 2. Barrel - 10.5" 5.56 / .223 Barrel. Click on the drop down box above to choose from our selection. 3. Handguard - MAS Defense "Ridgeline" 12.62" Slimline M-LOK Free Floating Handguard - (ID 1.25") 4. Gas Block - .750 Low Profile Steel Melonite Nitride ...Includes the parts listed below. You can customize the kit to fit your needs by clicking on the drop down boxes above. - Complete Kit for AR15 - Black. - Gear Head Works Tailhook MOD 1 Pistol Brace. - 8.2" Pistol Buffer Tube - Fluted. - 3oz Carbine Buffer. - Standard Buffer Spring. - Standard End Plate.7 Feb 2024 ... Comments420 · Is the Daniel Defense H9 any good? · Canik TTI Combat Review · Jailed For Assembling A Frame Or Receiver? · What You Need T...Was this review helpful to you? 0 of 0 people found the following review helpful: Great!! July 8, 2023 ... Enter your email address for special offers from MAS Defense LLC. 8334 Pineville Matthews Rd Ste 103 #254 Charlotte, NC 28226 [email protected]. Let's Stay In Touch.MAS Defense LLC is not and will not be held responsible for any city, county, state and/or federal laws that you (the purchaser) do not comply with. Due to the volatile nature and ever-changing laws regarding unfinished frames and lowers, these items are not returnable. ... Was this review helpful to you? 0 of 0 people found the following ...2. Barrel - 5.25" 9MM NATO (9x19) 1x10 4150 CrMoV Melonite Nitride Treated Steel. 3. Handguard - MAS Defense "NERO" 4.2" Slimline M-LOK Free Floating Handguard - (ID 1.25") 4. Muzzle Device - A2 Half Cage. Bolt Carrier Groups and Charging Handles are sold separately. All barreled uppers are head spaced and test fired to ensure function.Anyone dealt with MAS Defense? They are out of Charlotte, seems to be a home run type deal with no store front. I have seen some good reviews over on AR15.com, etc but looking to hear some reviews out of you guys. Prices seem to be great as well as the machining and work.5 Feb 2018 ... Please click on the link: http://shop. masdefense.com/MAS-DEFENSE-42- NERO-M-LOK-FREE-FLOAT-PISTOL-MAS Defense is an AR-15, AR-10 and Glock parts store. We are committed to providing every customer with Quality Parts at Reasonable Prices! Our foundation is built on excellent customer service, honesty and integrity.Defensive behavior occurs when an individual reacts to a perceived threat and begins using self-protective measures. Defensive behaviors come in a variety of forms, but typically t...mas defense upper update/review. I asked here a while ago about mas defense uppers as they didn't have a lot of reviews anywhere. they had the 13.7" barrel I was looking for so I wanted to throw a quick hands on review for anyone else looking into them..