June 5, 2024
By Lou Chavez, principal engineer, Security and Life Safety, Distinguished Member of Technical Staff, William Henry Merrill Society
Stopping a speeding bullet requires a mass or material that can overcome and absorb an incredible amount of kinetic energy at high velocities.
UL 752 is a test Standard for bullet-resisting equipment
The Standard’s requirements cover materials, devices, assemblies and fixtures used to form bullet-resisting barriers that protect against armed attack, such as those by snipers.
The term “bullet-resisting” signifies protection against complete penetration, passage of fragments of projectiles or spalling (fragmentation) of the protective material to the degree that a person standing directly behind the bullet-resisting barrier would not sustain any injury.
UL 752 was recently updated to include new requirements addressing ballistic attacks, with a growing demand for security against weapons used in urban settings.
Development history
In 2020, UL Standards and Engagement proposed reaffirming UL 752 as an American National Standard. During the reaffirmation process, several comments addressed new and existing ballistic risks, general improvements and clarifications of requirements throughout the current Standard. This included but was not limited to test risk specifications, performance levels, sample number, shot patterns and spacing, fair hit criteria, environmental conditioning, and witness panel specifications. In October 2020, a task group was formed with members representing Nationally Recognized Testing Laboratories (NRTLs), ballistics experts, law enforcement agencies, manufacturers, the National Institute of Standards and Technology (NIST), and UL Standards and Engagement Technical Committee members and staff. The task group focused on addressing test risk specifications and performance-level comments. Their recommendations were developed for consideration based on dynamic risk vectors and further consideration for industry input during the UL Standards and Engagement Physical Security Industry Workshop in March 2021. With the feedback gathered during the workshop, the task group was able to refine their recommendations proposed for two cycles of preliminary review and commenting before balloting.
Summary of changes
A high-level summary of the UL 752 Standard changes includes:
- Clarifications that limit the scope of the Standard, noting that UL 752 is not intended for worn or carried personal protective equipment.
- Revision of Table 11.1 terminology, proposing new performance designations that provide the standard description of firearms associated with each ballistic threat/ammunition; the new designations are identified with prefixes UL-HG for handgun, UL-RF for rifle and UL-SG for shotgun.
- Modification of Table 11.1’s organization by separating its content into three separate tables, simplifying the absorption of the information.
- Clarification and better definition of test range setup and requirements, shot patterns, fair hit requirements, conditioning procedures and witness panel descriptions.
- An informative annex with examples of firearms relative to ammunition.
See the new Tables 11.1, 11.2 and 11.3 below.
Table 11.1
Handgun Designations and Ammunition Specifications
| Handgun (HG) | ||||
| Designation | Ammunition | Weight | Reference velocity | Kinetic energy |
| UL-HG-A | 9 mm Luger FMJ RN | 124 grains (8.0 grams) | 1305 fps (398 m/s) | 467.3 ft⋅lb (633.6 J) |
| UL-HG-B | .357 Mag JSP | 158 grains (10.2 grams) | 1430 fps (436 m/s) | 715.1 ft⋅lb (969.5 J) |
| UL-HG-C | .44 MAG JHP | 240 grains (15.6 grams) | 1430 fps (436 m/s) | 1093.6 ft⋅lb (1482.7 J) |
| UL-HG-D | 9 mm Luger FMJ RN | 124 grains (8.0 grams) | 1470 fps (448 m/s) | 592.1 ft⋅lb (802.8 J) |
| Note: There is no hierarchy of threat severity in this list. |
Table 11.2
Rifle Designations and Ammunition Specifications
| Rifle (RF) | ||||
| Designation | Ammunition | Weight | Reference velocity | Kinetic energy |
| UL-RF-A | .30-06 Springfield JSP (7.62 x 63 mm) | 180 grains (11.7 grams) | 2700 fps (823 m/s) | 2922.5 ft⋅lb (3962.4 J) |
| UL-RF-B | 7.62 x 51 mm M80 Ball, NATO FMJ, Steel Jacket | 149 +0/-3 grains (9.7 +0/-0.2 grams) | 2780 fps (847 m/s) | 2566.3 ft⋅lb (3479.4 J) |
| UL-RF-C | .243 Winchester, Pointed Soft Point (PSP) | 100 grains (6.2 grams) | 3000 fps (914 m/s) | 1910.1 ft⋅lb (2589.7 J) |
| UL-RF-D | .270 Winchester, Pointed Soft Point (PSP) | 130 grains (8.4 grams) | 3100 fps (945 m/s) | 2766.4 ft⋅lb (3750.7 J) |
| UL-RF-E | 5.56 mm M193 FMJ BT, (5.56 x 45 mm) | 56 +0/-2 grains (3.6 +0/-0.1 grams) | 3390 fps (1033 m/s) | 1416.7 ft⋅lb (1920.8 J) |
| UL-RF-F | 5.56 mm M855 FMJ BT, (5.56 x 45 mm) | 61.8 ±1.5 grains (4.0 ±0.1 grams) | 3190 fps (972 m/s) | 1393.7 ft⋅lb (1889.6 J) |
| UL-RF-G | 7.62 x 39 mm Type 56, MSC FMJ, Copper- Plated Steel Jacket, Mild Steel Core Note: Surrogate round is under development. | 124 +0/-2 grains (8.04 +0/-0.1 grams) | 2480 fps (756 m/s) | 1694.6 ft⋅lb (2297.8 J) |
| UL-RF-H | 7.62 x 51 mm M80 Ball, NATO FMJ, Steel Jacket | 149 +0/-3 grains (9.7 +0/-0.2 grams) | 2780 fps (847 m/s) | 2566.3 ft⋅lb (3479.4 J) |
| UL-RF-I | .30 caliber M2 AP FMJ, (7.62 x 63 mm) | 165.7 +0/-7 grains (10.8 +0/-0.5 grams) | 2880 fps (878 m/s) | 3070.3 ft⋅lb (4162.8 J) |
| UL-RF-J | .50 caliber M33 FMJ Ball, mild steel core | 660 grains (42.7 grams) | 2910 fps (887 m/s) | 12389.2 ft⋅lb (16797.5 J) |
| Note: There is no hierarchy of threat severity in this list. |
Table 11.3
Shotgun Designations and Ammunition Specifications
| Rifle (RF) | ||||
| Designation | Ammunition | Weight | Reference velocity | Kinetic energy |
| UL-SG-A | Winchester, Ranger LE, 12 Ga., 2-3/4 Inch, 1 oz. Slug (Most common slug available) | 437.5 grains (28.3 grams) | 1200 fps (366 m/s) | 1398.0 ft⋅lb (1895.5 J) |
| UL-SG-B | 12-gauge 00 lead buckshot (12 pellets) | 650 grains (42 grams) | 1200 fps (366 m/s) | 2074.8 ft⋅lb (2813.1 J) |
| Note: There is no hierarchy of threat severity in this list. |
FAQs
Why was UL 752 revised?
UL Standards & Engagement received input that ballistic threats have changed. Code authorities and law enforcement confirmed the suggested ballistic threats and general input revisions. As a result, the Standard was updated and revised.
Is compliance with UL 752 required?
Compliance with UL 752 is voluntary. Testing and compliance enable a product to be listed and labeled for the specific ballistic resistance application(s) based on its performance designation. Typically, architects, engineers, consultants and other code authorities regard the UL label as proof of compliance with the end-product standard.
Does UL 752 cover bullet-resisting assemblies?
Yes, the 12th edition of UL 752 clarifies how bullet-resisting (B-R) assemblies are tested and evaluated. Typical assemblies include gunports, deal trays, package passers, voice panels and door-operating mechanisms.
What happened to the previous Level 1-10 ratings?
The 11th edition of UL 752 still uses Performance Level 1-10. The 12th edition uses performance designations — UL-HG-A, UL-HG-B, UL-HG-C, UL-HG-D, UL-RF-A, UL-RF-B, UL-RF-C, UL-RF-D, UL-RF-E, UL-RF-F, UL-RF-G, UL-RF-H, UL-RF-I, UL-RF-J, UL-SG-A and UL-SG-B. The change in the ratings reflects current ballistic characteristics. Code authorities, manufacturers and end users can easily recognize which standard edition was applied based on the rating designation nomenclatures to which the product was evaluated.
Portions of this article include excerpts from UL Standards. UL Standards are owned and copyrighted © by ULSE Inc. ULSE Inc. authorizes the use of these portions solely for use in this article.
Stay informed
Actionable insights on the topics you choose, delivered directly to your inbox.