S4015MS3EMC - Bernard BTB 400A MIG Gun, 15ft, Miller Style, 60 Degree Neck

Industrial Grade 400A MIG Welding Gun

The Bernard BTB (Best of the Best) Series MIG Gun represents a consolidation of the most reliable features from the legacy Q-Gun, S-Gun, and T-Gun platforms into a single, highly configurable solution. This specific configuration, identified by the SKU S4015MS3EMC, is an air-cooled, semi-automatic MIG gun rated for 400 amperes. It is engineered to withstand the rigors of heavy industrial welding applications, including structural steel fabrication, heavy equipment manufacturing, and shipbuilding.

The gun assembly features a 15-foot (4.6 meter) industrial-grade cable that ensures consistent wire feeding and durability against abrasion and heat. The power pin is a direct-connect Miller style, making it immediately compatible with a wide range of Miller wire feeders and integrated power sources without the need for adapters. The "S" in the part number typically denotes a specific handle profile, often the Small Curved handle, which is designed to fit comfortably in the welder's hand, promoting better control and reducing wrist strain during extended welding shifts.

At the front end, the gun is equipped with a 60-degree medium neck. This neck angle is the most versatile for general fabrication, allowing the operator to maintain proper gun angles in flat, horizontal, and vertical positions. The neck is rotatable, allowing for tool-free adjustment to access difficult joints. The consumable system is Bernard's proprietary Centerfire system, known for its "drop-in" contact tip design that eliminates cross-threading and ensures excellent electrical conductivity. The nozzle design typically features a built-in spatter shield to protect the gas diffuser.

Technical specifications include a 100% duty cycle rating when using CO2 shielding gas, and roughly 60% with mixed gases, ensuring the gun remains cool under continuous high-amperage use. The liner system is designed for smooth wire delivery, minimizing bird-nesting and feed issues. This gun is an essential tool for professional welders seeking reliability, ease of maintenance, and superior arc performance in a 400-amp package.