Can I use the four-tier stack a supplier recommends for a gun box?

Answer: Check lid load and shelf clearance. Four tiers put about 75 kg on the bottom lid, need rib spacing under 100 mm and 2.1 m of clear height.

How much smaller is the interior than the exterior?

Answer: With standard walls, expect 12 to 18 mm per side in length and width, and 25 to 30 mm in height.

How often does the gasket need replacing?

Answer: Count openings, not years. At correct compression an EPDM profile survives about 8,000 cycles, so five openings a week lasts three years.

Can the case be hosed down?

Answer: Rinse yes, but keep pressure under 0.3 MPa and avoid the gasket seam. Dry it open; 30 ml of trapped water shortens a 50 g charge by a tenth.

Does custom printing delay delivery?

Answer: Screen printing adds 5 to 7 days; in-mould labelling needs an insert, so plan from 15 days.

How to Choose a Gun Box: Five Decision Criteria

Quick answer: Fix how the gun box is stored and carried, then check footprint, base thickness, sealing and latches. Ranked in that order, the sheet narrows to two or three models before you ask for a price.

Five Decision Criteria for a Gun Box
Footprint and Stacking Before Capacity
Wall Thickness and Base Load
Sealing and Desiccant Cycles
Latches and Marking for Handover
FAQ

1. Five Decision Criteria for a Gun Box

Five gates decide whether the product works in service: storage and handling, footprint, thickness and base load, sealing, and latches with marking. The order matters, because each gate narrows the next. Stacked three high, the base carries the main load, so thickness follows the stack rather than the gasket.

Rank the five rather than scoring them. One unit put capacity first and bought two hundred oversized units; the shelving gave 1.6 m of clear height, two tiers fit, and each empty gun box weighed 3 kg more than needed.

Criterion	Settle this first	Typical value	Cost of getting it wrong
Handling	Shelved, stacked or vehicle-borne	Three-high stack	Overshoot or shortfall
Footprint	Shelf height and pallet plan	1220 x 420 x 210 mm	Wasted headroom
Thickness	Units sitting on top	4.0 mm base wall	Base bows under load

2. Footprint and Stacking Before Capacity

Footprint must satisfy shelf clearance, pallet plan and aisle radius at once. On a 1200 x 1000 mm pallet, a 1220 x 420 x 210 mm body loads twelve per tier; at 1350 mm long, only eight fit.

Gun box: a black hard case standing on a wooden range bench, top handle and two side latches, ear defenders behind

Stack height sets vertical duty. Three tiers mean the bottom unit carries two above it: at 25 kg gross the lid sees 50 kg, and a 1.5 safety factor puts rib spacing under 120 mm. Two tiers let the same gun box shed 0.4 mm of wall, and interlocking recesses hold stack offset under 5 mm.

3. Wall Thickness and Base Load

Thickness is easy to leave vague, because quotations say reinforced and never say where. Ask for three numbers: base, side and lid. For a 1220 x 420 x 210 mm body, 4.0 mm, 2.8 mm and 3.0 mm balance load against a 5.2 kg tare.

Deflection can be estimated. With four corner supports, the unsupported span runs about sixty percent of the length; at 25 kg, sag beyond 2 mm turns permanent within months and the lid stops seating. A cross-hatched rib grid 8 mm tall holds it under 0.8 mm.

Item	Light duty	Standard	Heavy duty
Base wall	2.8 mm	4.0 mm	5.0 mm
Unit weight	3.9 kg	5.2 kg	6.8 kg
Recommended stack	Two tiers	Three tiers	Four tiers

4. Sealing and Desiccant Cycles

Sealing comes from one gasket, not from cranking the latches. A 6 mm EPDM profile should sit at 25 to 30 percent compression: over-compress it and the rubber stops recovering, under-compress it and air migrates through the flange.

Gun box: an olive green long case lying in a pickup bed, two black straps lashed across, metal catches facing camera

Desiccant life is arithmetic. Fifty grams of silica gel in a 60 litre cavity saturates in about 90 days at 60 percent humidity, and in 35 days at 85 percent. Where a gun box opens daily, add a 4 mm breather port: open on arrival, close before dispatch, and the gasket stops being pushed open.

5. Latches and Marking for Handover

All-plastic catches are light and never rust, which suits frequent opening. Both styles need a 4.5 mm seal hole through the closed catch, or a gun box handover rests on signature alone.

Marking carries the rest of the trail. Reserve 100 x 60 mm on the short side for barcode and batch, repeat the number on the lid, and a two-hundred-unit count drops from 40 minutes to 12.

Trace item	Carrier	Check at handover
Batch number	Barcode label, short side	Scan on receipt
Seal state	Seal hole with tag	Visual check

Conclusion

Ranked properly, selection becomes subtraction: lock the stacking pattern, then let thickness and sealing follow it. The best unit is rarely the most expensive; it is the one whose base ribs and label position match the site. Specify the gun box by numbers, and it will behave like the one you tested.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.