In a patent infringement action against the US Army for its use of lead-free “green bullets,” the US Court of Appeals for the Federal Circuit concluded that the trial court erred in broadly construing a term of degree and the open-ended term “including.” Liberty Ammunition, Inc. v. United States, Case Nos. 15-5057; -5061 (Fed. Cir., Aug. 26, 2016) (Stoll, J).

This case stems from the US Army’s “green bullet” initiative from the 1990s and 2000s to eliminate lead from military ammunition. Prior to the development of so-called green bullets, the Army’s standard-issue ammunition was the M855 bullet. In response to the Army’s green initiative, a civilian engineer, P.J. Marx, developed and patented a lead-free bullet supposedly with the same lethality as the M855. 

After signing a non-disclosure agreement (NDA) with an Army official, Marx provided the Army with technical information and sample rounds of his bullets. Ultimately, however, the Army declined Marx’s bullets. In 2010, the Army announced the development of its own green bullet, the M855 A1. Subsequently, Liberty Ammunitions, the assignee of Marx’s patent, sued the US government in the US Court of Federal Claims for patent infringement under 28 USC § 1498 and breach of the NDA. Section 1498 waives the government’s sovereign immunity “[w]henever an invention described in and covered by a patent of the United States is used or manufactured by or for the United States without license of the owner thereof or lawful right to use or manufacture the same.”

After construing the disputed claim terms, the trial court held a bench trial and concluded that the government infringed the asserted claims. The trial court rejected the government’s construction of the claim terms “reduced area of contact” and “intermediate opposite ends.” The trial court construed the claim term “reduced area of contact” to mean that “the area of contact between the interface and the rifling of the firearm is less than that of a traditional jacketed lead bullet of calibers .17 through .50 BMG.” The government argued that this construction improperly used a range of calibers instead of the conventional M855 bullet as a baseline comparison. Further, the trial court rejected Liberty’s breach of contract claim, finding that the Army official who signed the NDA on the government’s behalf lacked authority to do so, rendering the NDA unenforceable. Both parties appealed.

In applying Phillips principles of claim construction, the Federal Circuit concluded that the disputed term “reduced area of contact” was one of degree and thus necessarily called for a comparison against a baseline. The M855 was the only prior art bullet disclosed in the patent specification, “strongly suggesting that the M855 round is the point of comparison for the claims.” Instead of using the M855 as a baseline, the trial court relied on a discussion in the patent specification of how the invention was enabled for “all calibers generally ranging from .17 through [.]50 BMG.” As the Federal Circuit explained, this was error because such a construction did not meet the “objective boundaries” standard for construing terms of degree. The Federal Circuit further explained that discussions in the patent specification of conventional bullets, such as the M855, and range of calibers were “distinct concepts,” and that the trial court erred in linking these distinct concepts in its claim construction.

The government also appealed the construction of the claim term “intermediate opposite ends.” Because the term “including” preceded the term “intermediate opposite ends,” the trial court concluded that the claimed “interface” may cover more than just the middle portion of the claimed bullet and could extend all the way to the front or end of a bullet. The government argued that the proper construction of this term should be limited so that the “interface” does not extend all the way to the front or end of a bullet.

The Federal Circuit agreed with the government, explaining that the trial court “significantly diminishes the ‘intermediate opposite ends’ limitation, almost to the point of rendering it a nullity.” The Federal Circuit reiterated its prior warning against using open terms, such as “comprising” or “including,” as “weasel word[s] with which to abrogate claim limitations.” 

The Federal Circuit construed the term “intermediate opposite ends” to mean that “the interface is positioned between the front end and the rear end of the projectile body such that the interface does not extend all of the way to the front end or to the rear end of the projectile.” Based on the correct claim construction, the Federal Circuit reversed the trial court’s finding of infringement. 

The Court also affirmed the trial court’s determination that the NDA was unenforceable for lack of implied actual authority. Judge Newman dissented from this aspect of the decision on the ground that the record contained sufficient evidence that the Army official had implied actual authority to sign the NDA.