Nestled among the prime goose hunting fields and Amish carriages of Maryland’s Eastern Shore, a nondescript warehouse just a few blocks behind the main road houses one of the state’s best kept secrets.

It’s a company whose name is a mouthful of acronymic letters that if you polled 100 gun enthusiasts, maybe five would know what it means. But show them one of the company’s firearms, and you’ll get near universal recognition.

And that’s just how LWRC International...