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Firearms & Field Optics

Designing and building firearms and field optics are precision arts. You’re working with tight, exacting tolerances with the barrel, bore and rounds and small clearances in moving assemblies. Outside of those areas, tolerances can be looser and designs must account for repeated assembly and disassembly. Weapons are traditional mechanical devices and the design focus is on clearances and fits, where size, location, orientation and form (SLOF) are critical considerations. Mistakes can mean massive liability, so even if you’re sourcing parts, you’re doing the machining and fitting in house.

The focus of optics design is precise alignment for lensing. The inspection of optics is extraordinarily difficult because the tolerance band for parts is so tight that many CMM’s can’t measure it. And whether you’re making the barrel, or the brackets and scope that sit on top of it, the end optic is critical and every part must be aligned on a 100 percent basis. Mistakes in alignment compound quickly, so using datums ensures attachment points preserve the alignment of every critical component.

For firearm OEMs, coaxial alignment and modular design are the name of the game, because magazines, grips, barrels, sights and scopes must all be replaceable and interchangeable, and you’ve got to account for variation in assemblies. The challenge is even greater when you’re a 3rd party part maker -- you have to guarantee fit for your customers even though you’re bolting onto a gun design that you have no control over.

At GD&T Basics, we count Leupold and Winchester among our many clients the industry. Gunsmithing has a storied history, and we know that craftsmanship is a core value of the industry. We also know how that sort of culture can silo knowledge and prevent standardized processes and communication – which makes getting new people up to speed a challenge. And with manufacturers doing 100% functional inspections during assembly, you need every part to be well-toleranced so they fit together the first time.

GD&T was literally invented to create alignment in systems. It also standardizes your communication and gets everyone on the same page. Good documentation of your designs makes part production more predictable and helps guarantee that assembly goes smoothly. GD&T also lets you develop clear and concise inspection plans and eliminate the complications of using coordinate or polar dimensioning. Just using GD&T’s max material condition can be a huge time and money saver because it gives you clear, unambiguous, rejectable criteria on the design.

At GD&T Basics, we teach your people what they need to know of the ASME 14.5Y standard, and provide them the context needed to understand how the part will function, and how it’ll be made, tested and inspected. Understanding the context of an entire project streamlines communication with suppliers, clients, and co-workers, and helps avoid problems before they start. Our instructors have a lot of experience with runout and cylindricity, the types of tolerances most needed in making firearms and field optics. We’ve seen plenty of good and bad drawings during our decades as engineers and GD&T consultants, and that’s how we can specialize in real-world application of GD&T concepts.

We understand that there may be a lot of inertia behind your existing systems and methods, but we also know how to show students that coordinate and polar dimensioning simply don’t work as well as GD&T. GD&T eliminates complexity and ambiguity, and our trainers specialize in making GD&T simple, straightforward and relevant to the work you do. Our aim is not to tell you to change all of your drawings, but to show you the changes you can make to improve the quality of your work and the efficiency of your operation.

Contact us today and we’ll work together to build your team’s perfect training program.