Is 1.2 mm steel enough?

Answer: For the body, yes; the door needs 1.5 mm or a metre-wide leaf springs back.

Can aluminium replace stainless?

Answer: Where weight matters, yes; where washdown matters, no. Aluminium passes 480 hours of salt fog, 304 reaches 720.

Can a plastic gun case stay outdoors?

Answer: Not advised. UV chalking and cracking below -20 °C appear within two seasons; a covered walkway is the limit.

Will a plywood unit pass acceptance?

Answer: Dry indoor and short-term, yes, with a moisture report under 12 percent.

Is there a fifth route?

Answer: Glass-fibre composite at three times the cost of steel, earned only where a gun case must be light, salt-proof and metal-free.

Where does the price difference sit?

Answer: Material is about 60 percent, finishing 20, the rest in latches and shelves.

Four Lines, Three Numbers: A Gun Case Material Checklist

Quick answer: A gun case quote can differ twofold, and the material route explains most of it. Cold-rolled steel is cheap but hates washdown, aluminium saves weight at 1.6 times the price, 304 passes salt fog, and plastic or plywood suits only light, short service.

Gun Case Material Routes: Settle the Material First
Line One: Cold-Rolled Steel, Gauge and Weight
Line Two: Aluminium Alloy Against Stainless
Line Three: The Plastic Temperature Window
Line Four: Plywood and Composite Residual Value
Three Numbers: When Not to Choose a Gun Case
FAQ

1. Gun Case Material Routes: Settle the Material First

Two quotes, eighty thousand against thirty, differ almost entirely in material route. Settle that before latches and shelves.

Route	Gauge	Weight	Best for
Cold-rolled steel	1.2–1.5 mm	85 kg	fixed indoor, tight budget
Aluminium alloy	2.5 mm	38 kg	hoisting, frequent moves
Stainless 304	1.2 mm	78 kg	washdown, cleanroom
Engineering plastic	4 mm	26 kg	light duty, temporary

The order is fixed: washdown and salt fog, then movement, then shelf load. Swapped, the material comes out too expensive or too thin.

A wrong route is not patched by thicker sheet.

2. Line One: Cold-Rolled Steel, Gauge and Weight

Steel is the default. 1.2 mm with folded ribs at 150 mm centres holds stiffness; the door needs 1.5 mm because it is a cantilever.

Gun Case: a grey hard-shell trolley case in an airport waiting area, handle extended, four spinner wheels, metal-and-wood seat rows beside it

Weight belongs in the quote. An 85 kg unit takes two on the flat and four on stairs; past 120 kg it needs a pallet truck, a detail sites discover at the stairwell.

Powder coating runs 60 to 80 μm over phosphated steel; skip that and weld seams blister within two years.

Steel has one weakness: washdown.

3. Line Two: Aluminium Alloy Against Stainless

Aluminium answers weight, not corrosion. A 2.5 mm shell weighs 38 kg where steel takes 92, at 1.6 times the price, and thin aluminium cannot be welded, so load paths need insert blocks.

Four lines of division settle it:

Hoisting to a roof: aluminium, the crane bill covering the difference.
Moving every task: aluminium, with better wheel mounts and lifting points.
Pressure washing: 304, which passes 720 hours of neutral salt fog at 1.2 mm.
Light and washed: aluminium with a liner, plus 30 percent on price.

304 costs 2.4 times steel, buying the gap between 720 and 240 hours; indoor sites usually pay it for cleanroom washdown, not salt.

4. Line Three: The Plastic Temperature Window

Plastic works in light duty once the temperature window is in the contract. PP runs -20 °C to +60 °C; outside that a 1 m drop can crack it unseen by room-temperature tests.

Gun Case: a navy hard case on a baggage carousel belt, light scuffs on the lid, two front catches and a folding handle, windows behind

Item	Value	Check	Usual mistake
Wall	4 mm	calipers, three points	rim only
Window	-20 to +60 °C	drop after cycling	room-temperature drop
Shelf load	25 kg	24 h distributed	point load
Threads	M6 brass insert	800 N pull-out	tapping the plastic

Plastic fails by creep, not fracture. A shelf under 25 kg distributed sags 3 to 4 mm in a day, an allowance that belongs in the design.

Five years against ten for steel explains both price and replacement.

5. Line Four: Plywood and Composite Residual Value

Plywood survives in one setting: dry indoor, short turnaround, lowest budget. Moisture content must stay under 12 percent, or the panels warp in three months.

Glass-fibre composite sits between weight and corrosion at three times the price of steel, worth it only where a gun case must be light, salt-proof and metal-free.

Plywood's residual value is that it comes apart: flat panels ship in a third of the volume.

6. Three Numbers: When Not to Choose a Gun Case

Three numbers settle it: price multiple, weight, service life.

Three exceptions matter. Under three weapons carried by hand, a box beats a gun case because fixed cost never amortises. Past 60 minutes of fire resistance, plain steel fails and a lined cabinet is the only route. On a three-month site, plywood depreciates better.

Where the site is fixed, shelf load passes 80 kg and service runs beyond eight years, steel or 304 is never wrong.

Conclusion

After four routes the decision is a multiplication: price multiple, weight constraint, service life. The cheapest result is usually right; only where the arithmetic stays flat do washdown and salt fog decide the gun case.

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.