Discreet blank firing adapter

Description (excerpt)

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority to U.S. Provisional Patent Application Ser. No. 63/523,760, filed Jun. 28, 2023, entitled “ISCREET BLANK FIRING ADAPTER,” and U.S. Provisional Patent Application Ser. No. 63/627,848, filed Feb. 1, 2024, entitled “DISCREET BLANK FIRING ADAPTER,” the disclosure of which is expressly incorporated by reference herein. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT The invention described herein was made in the performance of official duties by employees of the Department of the Navy and may be manufactured, used and licensed by or for the United States Government for any governmental purpose without payment of any royalties thereon. This invention (Navy Case 211643US03) is assigned to the United States Government and is available for licensing for commercial purposes. Licensing and technical inquiries may be directed to the Technology Transfer Office, Naval Surface Warfare Center Crane, email: Crane_T2@navy.mil. FIELD OF THE INVENTION The field of invention relates generally to safety mechanisms for preventing firearms from firing live ammunition. More particularly, it pertains to a discrete blank firing adapter for a firearm that prevents a bullet or any bullet fragmentation from a fired live round from exiting a firearm barrel and traveling downrange. BACKGROUND During force on force training exercises, negligent discharges of live rounds are periodically encountered that can lead to injury or death. It is also possible that someone would intentionally attempt to load and fire live rounds during a training scenario with the intent to do harm. There is a need for a blank firing only training system that increases safety by successfully addressing the scenario of a negligent or intentional discharge of a standard combat cartridge in the training. Prior methods of discouraging the firing of standard combat ammunition in training weapons include cartridge feeding discriminators (such as modified magazines or feed trays), custom barrels with unique chambers and unique blank training ammunition, physical impediments in the barrel to prevent chambering of standard combat cartridges (such as U.S. Pat. Nos. 8,683,728 and 9,188,402), and various gas venting methods (such as U.S. Pat. No. 5,740,626) that attempt to slow down or prevent the bullet from a standard combat cartridge from exiting the barrel. With exception to a custom barrel and unique cartridge chamber with unique blank ammunition (of a non-standard configuration), the other proposed solutions are not completely reliable. Even the solutions that suggest a physical impediment just forward of the cartridge chamber (to interfere with the bullet of an incoming standard combat cartridge) do not always reliably induce the desired effect and will sometimes allow for the bullet to be farther seated within the cartridge case during chambering and still be fired. Methods such as gas venting are also problematic in that these solutions allow for the possibility of bullet stack-up to occur within the barrel, which can lead to dramatic overpressure situations and catastrophic failure. This can lead to safety risks for both the operator and those who may be in close proximity. While solutions relying on custom barrels with unique cartridge chambers and unique ammunition can prevent the chambering of standard combat ammunition, these solutions are costly and inherently demand dependence on unique and often proprietary, non-standard blank cartridges. This drives up lifecycle costs and introduces unwanted logistics and acquisition challenges in order to fund and maintain the required barrel and ammunition inventories. Other methods currently employed include the use of external blank fire adapters (BFAs). For most current military applications, the BFA is attached externally, with respect to the barrel bore, in a manner allowing for intentional visibility. Often times, the BFA is attached to the barrel in one of two ways. Either it attaches to an existing muzzle device, such as a flash hider, or it replaces that existing muzzle device and attaches directly to the external muzzle threads that are there. The former method is popular for systems that do not employ dedicated blank fire barrels because the BFA can be selectively attached and used as needed to support training activities with blank ammunition. The latter method is more popular for applications using dedicated blank fire barrels as it allows for a simpler and more cost-effective BFA design. The latter approach is also often used for applications desiring to permanently secure the BFA to the barrel via example methods such as welding or pinning, either with or without a threaded connection. In both prior art designs as described above, these devices require the BFA to be attached externally, which may be undesirable in instance where authenticity is sought, or where an external device is to be attached to the firearm (such as a suppressor). As can be seen from the above, there is a need for a blank firing adapter that prevents a bullet or any bullet fragmentation from a fired live round from exiting a firearm barrel and traveling downrange, is not externally visible, and allows for attachment of external devic