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to the shooter without decreasing shooter capability as long as Disclosure
added weapon length is not detrimental to mission outcomes. The authors have nothing to disclose.

Recommendations Funding
This work was supported by the Office of the Assistant Secre-
We think .50-caliber rifles can be successfully integrated into tary of Defense for Health Affairs, through the Broad Agency
operations with minimal disturbance and risk to shooters if Announcement (Award no. W81XWH-16-2-0001) for all ma-
care is taken. Where possible, avoid firing from inside enclosed terial and transportation costs.
spaces or atop rigid structures. Substantial attention should
be applied to muzzle device selection. If resources allow the Disclaimer
integration of a suppressor onto the weapon platform, it is Opinions, interpretations, conclusions, and recommendations
highly advisable. We also recommend firing from the stand- are those of the authors and are not necessarily endorsed by
ing position where possible. To facilitate a stable platform, the Department of the Army or the Department of Defense.
secondary equipment such as rifle rest/tripods (e.g., Spec-rest, No funding or discount was offered by TacFlow academy
HOG Saddle, and Reaper Grip) is worth investing in for oper- aside from access to subjects and facilities.
ational deployments. Training doctrine should also note that
when firing with multiple shooters on the line, or with spot- Author Contributions
ters and instructors near the shooter, it is possible that these ML provided access to the training facilities and overall struc-
immediate bystanders are also receiving OP of greater than ture to the research questions and writing assistance. GHK
the 4-psi threshold. In addition, due to the forces involved, provided the scientific investigation, research protocol, fund-
double ear-protection (i.e., in ear and over ear) devices are ing, material, and writing assistance. AM collected the field
strongly suggested to be used at all times for operators and data, prepared the data for analysis, and provided editorial
observers. support. CRL conducted analyses and contributed signifi-
cantly to the conceptualization and drafting of the manuscript.
ANR and MYG assisted significantly in data preparation and
Conclusion
collection. MJE drafted the manuscript and conducted the
Taken together, a capable .50-caliber rifle program can be de- analyses.
veloped that minimizes potential risk to shooter health and
effectiveness without compromising field capability and read- References
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We thank SPC Bill McQuiggan, SPC T. Reece, SGT A. Alviar, rotrauma mouse model. Sci Transl Med. 2012;4(134):134ra60.
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in this manuscript. We thank contributing staff of the Wal-
ter Reed Army Institute of Research for their assistance in the
completion of this study and the preparation of this article.

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