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2-t-series-lg-straight_left_web 2-o-series-sm-curved_left_web T series straight handle option for BTB semi-automatic air-cooled MIG guns O series small curved handle option for BTB semi-automatic air-cooled MIG guns O series curved handle option for BTB semi-automatic air-cooled MIG guns

S-Gun Semi-Automatic Air-Cooled MIG Guns

Optimize for Productivity. Standardize for Simplicity.

Bernard® S-Gun™ semi-automatic air-cooled MIG guns are engineered for superior performance in hard-to-feed applications. 

Available in a 300 amp and 400 amp, with T-Series (standard, locking triggers) or O-Series (stand trigger) handles, the S-Gun MIG guns are built-to-order.

Multiple handle and trigger options

  • Choose between seven different curved and straight handle styles
  • Wide selection of handles and easy-to-change trigger options allow guns to be matched to user preference and welding application

Fixed or rotatable necks

  • Wide variety of angle and length options
  • No tools required to adjust rotatable necks
Rotatable neck for BTB semi-automatic air-cooled MIG gun shown in several different positons to demonstrate rotatability

High-performance consumables

AccuLock S consumables family including contact tip, nozzle, diffuser, liner and power pin

Durable steel monocoil cable design

  • Steel monocoil cable for extra pinch/kink resistance
Cutaway of steel monocoil cable showing internal cable, trigger leads and copper

Liner options

AccuLock S liner family

Processes

  • MIG (GMAW) welding

Duty Cycle Rating

  • 300 amp model – 100%: 300 amp with CO2, 60%: 300 amp with mixed gases
  • 400 amp model – 100%: 400 amp with CO2, 60%: 400 amp with mixed gases

Cable Length Options

  • 15, 20 and 25 feet

Wire Size Ranges

  • 0.030″ (0.8 mm) to 5/64″ (2.0 mm)

S-Gun™ Semi-Automatic Air-Cooled MIG Gun Configurator

Configure the S-Gun semi-automatic air-cooled MIG gun part number your need, or reverse lookup your existing gun part number – plus get access to additional resources and an expanded replacement parts list with diagram.

This mobile-friendly online configurator, now including Bernard® AccuLock™ S Consumable options, provides downloadable exploded view diagrams and other valuable takeaways that you can print, save in PDF format for later, or share via email.

Part Numbers

Consumables Systems

MIG Gun Liners

AccuLock S liner family
Front Load Liners
Family of color-coded Bernard conventional liners
Bernard® Rear Load Liners
Set of two Tregaskiss conventional liners for MIG welding guns
Rear Load Liners for Aluminum Wire

Consumables Systems

MIG Gun Liners

Important: Front load liners are a critical component of the complete AccuLock S consumables system, and can only be used with AccuLock contact tips, diffusers, nozzles, neck insulators, power pins and power pin caps specific to the system.

>> See Front load liner part numbers

Part NumberDescription
L2A-15for 0.030″ – 0.035″ wire; 15 ft length
L2A-25for 0.030″ – 0.035″ wire; 25 ft length
L3A-15for 0.035″ – 0.045″ wire; 15 ft length
L3A-25for 0.035″ – 0.045″ wire; 25 ft length
L4A-15for 0.045″ – 1/16″ wire; 15 ft length
L4A-25for 5/64″ wire; 25 ft length
L6A-15for 5/64″ wire; 55 ft length
L6A-25for 5/64″ wire; 25 ft length
Part NumberDescription
415-35-2Steel wrapped nylon liner for 0.035″ – 0.045″ wire, 15 ft length
415-45-03Polymer liner for 0.035″ – 3/64″ wire, 15 ft length
415-45-04Steel wrapped nylon liner for 0.035″ – 0.045″ wire, 25 ft length
415-116-2Steel wrapped nylon liner for 0.045″ – 1/16″ wire, 15 ft length
415-116-23Polymer liner for 3/64″ – 1/16″ wire, 15 ft length

In addition to the options and features included in our configurator, customers can choose from a variety of gun options and accessories that can help to further customize their gun to their personal preferences and the job at hand:

  • Q-neck coupler and grip
  • Flex necks
  • Jump liners
  • Heat shield
  • Neck guard
  • Specialty nozzles
  • Gun hanger
  • Repair kits

Documentation

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Consumables

How-Tos

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Videos

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Related Products

Product Updates

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Additional Resources

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Copyright 2025 Tregaskiss | All Rights Reserved

As manufacturers of semi-automatic, fixed automatic and robotic MIG guns and consumables, Tregaskiss and Bernard have earned a reputation as an experienced, dependable partner to its customers in the automotive, construction and fabrication, heavy equipment, ship, rail, general manufacturing, commercial truck and trailer, and oil and gas industries. Tregaskiss and Bernard offer air-cooled semi-automatic, fixed automatic and robotic MIG guns, water-cooled semi-automatic, fixed automatic and robotic MIG guns, reamers, nozzle cleaning stations, anti-spatter liquid, wire cutters, anti-spatter sprayers, clutches, welding consumables, nozzles, MIG welding tips, and MIG welding torches.