For several years it has been debated whether or not .22 LR could or could not penetrate soft armor vests.
Originally, in the 1970’s, Kevlar soft armor was developed to protect Officers against common street threats, which typically were .22 LR LRN, .32 ACP LRN, and .38 SPL LRN. Threat level I vests were certified to stop these ubiquitous, low-velocity threats. As time went on, the threats escalated, and more powerful rounds became common, necessitating thicker vests. But, with the advent of the internet, rumors persisted and spread that called into question whether or not the .22 LR could pose a valid threat to lower level soft armor (I and IIA).
Level I soft armor is seldom seen in this day and age. Typically comprising between 6 and 10 layers of woven aramid, it lacks the thickness to provide sufficient protection against backface deformation. Surprisingly, Level I armor will often stop rounds such as .45 ACP hardball @ 850 FPS, or even .40 S&W. However, these rounds leave a very large backface signature, regardless of whether they are stopped by the armor.
.22 LR has the distinction of being a very good penetrator, primarily due to basic physics- it has a very small frontal area, and can achieve relatively high velocities (1400 FPS from a 16-20″ barrel is not unheard of in certain loadings, I.E. CCI Velocitors). However, it is not a jacketed round, and therefore deforms fairly easily.
The NIJ specifications for Level I call for it to be able to stop .22LR LRN at or below 1050 FPS. Now, it is very important to note the velocity threshold- most longer barrels (above 10″ or so) push .22 LR above this velocity, and therefore can be expected to defeat level I armor. The ongoing debate on the Interwebs rages, but without paying much attention to the distinction between .22 out of a short barrel (handgun) vs. a long barrel (rifle). In order to (hopefully) put this debate to rest, I am posting a test.
This test is aimed at settling the longstanding debate on whether .22 LR is a threat to lower rated soft armor (I and IIA) Furthermore, it seeks to establish whether it is a viable threat only in longer barrels, or both long and short barrels, when faster ammo/more pointed rounds are used.
For this test, the ammo used is Remington Viper 36gr. Hypervelocity round, which features a solid copper washed truncated cone lead bullet and a stated MV of 1410 fps (out of a 20″ barrel). This round was chosen as the shape is more conducive to penetration (smaller frontal cross section). This is fired from a 16″ and a 4″ barrel, from 12 inches.
The panels (two level I and two level IIA) are identical, and will each be shot only once to allow for their full ballistic potential to be evaluated vs. each barrel length. The level I panels comprise 7 layers of Kevlar 29, while the level IIA panels comprise 12 layers of the same material. The backing material is Roma Plastalina #1 modeling clay, to allow backface deformation/penetration to be evaluated and observed.
Stay tuned for the results.
d-rmor gear 