UL 752 ballistic glazing — a contractor's-eye reference.

UL 752 levels, what they actually stop, and why ballistic glazing is a frame-and-wall system, not a piece of glass. Written for Florida courthouse, police, and government-facility work.

Controlling doc UL 752 Related tests ASTM F1642 (blast) · F1233 (forced entry) Author Connor Walsh · President
Sheet T-101 · The controlling document

UL 752 — Standard for Bullet-Resisting Equipment.

UL 752 is UL's Standard for Bullet-Resisting Equipment — the test standard almost every U.S. ballistic glazing spec references, whether it's written for a courthouse, a police lobby, or a pharmacy service window. UL 752 defines a set of performance levels, each tied to a specific firearm, caliber, bullet weight, and number of shots fired at a defined distance. A glazing assembly (or door, or wall panel) passes a level if it stops full penetration at that level's test parameters.

Two things matter for anyone pricing or specifying this work. First, UL 752 levels are not cumulative in a simple sense — going up a level generally means a bigger jump in material thickness and weight, not just "a little more glass." Second, UL 752 rates the material in a test rig. What actually goes into a building is a system — glazing, frame, and the wall or storefront it's anchored to — and the installed system has to be detailed to match what was tested, or the rating doesn't transfer to the field condition.

Sheet T-201 · Reference schedule

UL 752 levels — what each one is tested against.

UL 752's 11th Edition uses numbered Levels 1–10; a newer 12th Edition reorganizes the same threats into handgun (UL-HG), rifle (UL-RF), and shotgun (UL-SG) designations. Both editions are currently in specification use. Levels 1–8 cover the range seen on architectural glazing; Levels 9–10 (armor-piercing rifle, .50 caliber) are specialty military/defense applications rarely built into commercial glazing.

UL 752 protection ladder — levels 1–8 by tested projectile velocity LEVELS 1–3 — HANDGUN THREATS L19mm handgun3 shots tested1,175–1,293 fps L2.357 Magnum handgun3 shots tested1,250–1,375 fps L3.44 Magnum handgun3 shots tested1,350–1,485 fps LEVELS 4–8 — RIFLE-CLASS & HIGH-VELOCITY THREATS L4.30-caliber rifle1 shot tested2,540–2,794 fps L57.62mm rifle1 shot tested2,750–3,025 fps L69mm submachine gun5 shots tested1,400–1,540 fps L75.56mm rifle5 shots tested3,080–3,383 fps L87.62mm rifle, multi-shot5 shots tested2,750–3,025 fps BAR LENGTH = MAXIMUM TESTED PROJECTILE VELOCITY (FPS) · SOURCE: UL 752 TEST PARAMETERS ABOVE
Fig. 1 — The eight standard UL 752 levels, scaled by tested projectile velocity. Level 4 is where glazing thickness jumps.
1
9mm handgun
3 shots, 124-grain 9mm FMJ, 1,175–1,293 fps. The baseline commercial level — retail counters, pharmacies, gas stations.
2
.357 Magnum handgun
3 shots, 158-grain .357 Magnum jacketed lead soft point, 1,250–1,375 fps.
3
.44 Magnum handgun
3 shots, 240-grain .44 Magnum lead semi-wadcutter gas-checked, 1,350–1,485 fps. Common minimum for courthouses and government service counters.
4
.30-caliber rifle
1 shot, 180-grain .30-caliber rifle lead-core soft point, 2,540–2,794 fps. First rifle-rated level; a significant jump in glazing thickness from Level 3.
5
7.62mm rifle
1 shot, 150-grain 7.62mm (.308 caliber) lead-core FMJ military ball, 2,750–3,025 fps.
6
9mm submachine gun
5 shots, 124-grain 9mm FMJ, 1,400–1,540 fps — same round as Level 1, higher velocity and shot count.
7
5.56mm rifle
5 shots, 55-grain 5.56mm (.223 caliber) FMJ, 3,080–3,383 fps.
8
7.62mm rifle, multi-shot
5 shots, 150-grain 7.62mm (.308 caliber) FMJ military ball, 2,750–3,025 fps. Practical ceiling for most architectural glazing assemblies.

UL 752 also includes a supplementary shotgun rating (12-gauge rifled slug and 00 buckshot) and Levels 9–10 for armor-piercing rifle and .50-caliber threats. Level assignment and required test data always come from the project spec and the manufacturer's UL-certified test report for the specific assembly — this table is a reference starting point, not a substitute for the sealed submittal.

Sheet T-301 · Standard families

Ballistic, blast, and forced-entry are three different problems.

These three terms get used loosely on the phone and get confused in early-stage specs. They test different failure modes, and a product rated for one does not automatically satisfy another:

  • Ballistic (UL 752): Can a bullet, fired at a defined caliber and velocity, penetrate the assembly? This is a stopping-power test — the threat is a projectile.
  • Blast (ASTM F1642, ASTM F2912): Does the glazing survive an air-blast pressure wave without becoming a flying hazard inside the building? See ACG's AT/FP blast-rated glazing reference for the full standard family — UFC 4-010-01, F1642, F2248, F2912.
  • Forced entry (ASTM F1233): Can an attacker breach the opening with tools, repeated blows, or a combination of tactics within a defined time window? This is a delay-time test, not a stopping-power test. See ACG's forced-entry resistant glazing reference for F1233 and the newer F3561 systems standard.

A single assembly can be rated to more than one of these — many high-security storefronts combine a UL 752 ballistic rating with an F1233 forced-entry rating, because the realistic threat is a shooter who also tries to force the opening. But that combination has to be tested and specified explicitly. "Bullet-resistant" on a submittal doesn't tell you anything about blast or forced-entry performance, and vice versa.

Sheet T-401 · System detailing

Ballistic glazing is a system — glass, frame, and wall.

UL 752 tests a specific configuration: the glazing material, in a specific frame, anchored a specific way, in the test lab. That configuration — not just the glass makeup — is what carries the rating. A few things that follow from that:

  • Frame has to match the tested assembly. Swap a lighter-gauge frame or change the anchor pattern and the field installation is no longer the tested configuration, whatever the glass itself is rated for.
  • Wall/substrate anchorage has to develop the frame's rating. A Level 3+ ballistic frame anchored into a substrate that can't resist the reaction load defeats the point — the frame tears out before the glass fails.
  • Perimeter framing (mullions, transoms, sidelites) needs the same rating as the primary lite. A ballistic-rated door in a non-rated sidelite assembly leaves an obvious gap in the protection.
  • Doors carry weight and hinge implications most people don't budget for. Ballistic-rated glazing at Level 3 and above gets heavy fast — a Level 8 assembly can run in the mid-teens of pounds per square foot. Door hardware, hinges, closers, and the frame itself all have to be specified for that dead load, not standard-glass hardware.
Sheet T-451 · Where it's specified

Where ballistic glazing actually shows up on Florida projects.

UL 752 ballistic glazing is specified where a facility has a defined, foreseeable ballistic threat at a public-facing counter or opening — not as a blanket security upgrade for an entire building envelope. The recurring building types:

  • Courthouses — clerk's counters, security screening lobbies, judges' chambers glazing.
  • Police department lobbies and report-writing counters — public-facing transaction windows.
  • Utility payment windows and government service counters — tax collector, utility billing, DMV-type counters.
  • Pharmacies — service windows, particularly narcotics storage areas.
  • Schools — main-entry vestibules and front-office transaction windows, generally at the lower end of the level range (1–3) combined with forced-entry performance.

The controlling level is always set by a project-specific threat assessment, not a rule of thumb — but Level 1–3 (handgun-range) covers the large majority of public-counter applications; Level 4 and above is reserved for facilities with a defined rifle-range threat.

Sheet T-601 · General notes

Common Div 08 spec traps on ballistic scopes.

Glass-only specs that ignore the frame

Spec calls out a UL 752 level for "the glazing" and leaves the frame and anchorage undefined. The rating is meaningless without a tested frame-and-anchor configuration — this needs an RFI before pricing.

No-spall vs. spall ratings

Some ballistic assemblies stop the round but still shed glass fragments (spall) on the protected side; "no-spall" or "spall-resistant" configurations add a backing layer specifically to control that. If the application is an occupied counter at arm's length, confirm which behavior the spec actually wants.

Door weight and hinge capacity

Ballistic-rated doors at Level 3+ are heavy. Standard storefront hinges and closers often aren't rated for the dead load — this has to be caught at submittal, not at hang time.

Edition confusion (11th vs. 12th)

Older specs cite Levels 1–10; newer manufacturer literature uses UL-HG/UL-RF/UL-SG designations. Confirm which edition the spec and the test report are written to before assuming equivalence.

Combined ballistic + forced-entry assumed, not specified

A public counter often needs both a ballistic rating and forced-entry resistance (ASTM F1233), but the spec sometimes only calls out one. Worth flagging at bid stage if the use case clearly needs both.

What we do about it

We flag each of these in writing at the RFI stage on any ballistic scope we price — before we quote, not after award.

Impact-rated punched window openings at the Haines City Public Safety Complex and EOC Haines City EOC · Risk Category IV
Where ACG's experience sits

Essential-facility experience, stated plainly.

ACG prices ballistic glazing scopes to the project-specified UL 752 level as a Division 08 subcontractor — coordinating glazing, frame, and anchorage as the single tested system the rating actually depends on. Our verified public-sector past performance is essential-facility work — the Haines City Public Safety Complex & EOC (25,443 SF, GC Pirtle Construction, completed 2025), the Cudjoe Key fire station for Monroe County, and the Martin County Fire Training facility. Laminated impact assemblies, Risk Category IV design pressures, and the documentation chain that comes with institutional owners.

Government contractor overview
Related questions

UL 752 questions specifiers ask.

What is UL 752?

UL 752 is UL's Standard for Bullet-Resisting Equipment — the test standard used to rate glazing, doors, and barriers against specific firearm threats. It defines numbered performance levels (or, in the newer edition, handgun/rifle/shotgun designations), each tied to a specific caliber, bullet weight, velocity, and shot count. An assembly passes a level if it stops penetration under those exact test parameters.

What UL 752 level is typical for commercial and government projects?

Levels 1–3 (handgun range, up through .44 Magnum) cover the large majority of retail, pharmacy, and public-counter applications, including most courthouse and police-lobby transaction windows. Levels 4 and above are reserved for facilities with a defined rifle-range threat in a project-specific threat assessment — the controlling level is always set by that assessment, not a general rule.

Is "ballistic glass" the same as "bulletproof glass"?

"Bulletproof" is a marketing term, not a technical rating — the accurate term is bullet-resistant, and any assembly's resistance is defined by the specific UL 752 level it's tested and certified to, not an absolute claim. A Level 3 assembly resists the Level 3 test threat; it is not rated against a Level 8 rifle threat.

Does ballistic glass stop rifle rounds?

Some does, and some doesn't — it depends entirely on the tested level. UL 752 Levels 1–3 are handgun-range and are not rated against rifle fire. Levels 4–8 are specifically rifle-rated, but require significantly thicker, heavier glazing and a frame system engineered to match. A Level 1–3 assembly will not stop a rifle round; assuming otherwise is a real, documented risk in under-specified projects.

Does ACG price UL 752 ballistic glazing scopes?

Yes. ACG prices and installs ballistic glazing systems — glass, frame, and anchorage — to the project-specified UL 752 level as a Division 08 subcontractor. ACG's verified public-sector past performance is essential-facility work — the Haines City Public Safety Complex & EOC, the Cudjoe Key fire station (Monroe County), and the Martin County Fire Training facility. FL CGC #1531993.

What's the difference between ballistic, blast, and forced-entry glazing?

They test different threats. Ballistic (UL 752) tests whether a bullet penetrates the assembly. Blast (ASTM F1642/F2912) tests survival of an air-blast pressure wave. Forced entry (ASTM F1233) tests how long an assembly resists a physical breach attempt. A product rated for one does not automatically satisfy another — combined ratings have to be tested and specified explicitly.

Related pages

Sending a ballistic glazing scope to bid?

Send Division 08 to [email protected]. We read it against the specified UL 752 level, check frame and anchorage against the tested configuration, and surface any bid-stage risks in writing before we quote.

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