Multi-Shot Firework Cakes: Understanding the Impact

Two boxes, side by side, both labelled 25 shots, both about the same size, one costing twice as much as the other. Anyone who has stood in a fireworks shop has faced this and wondered whether the expensive one is better or just better marketed. Usually it is better, and the reasons are printed on the label if you know where to look.

This is a guide to what produces impact in a multi-shot cake, so you can compare products on something more useful than the shot count.

Shot count is the least important number

Every multi-shot cake is a group of tubes fired in sequence from one fuse. The shot count is simply the number of tubes. What comes out of each tube depends on its diameter and how much powder is behind it, and those two things vary enormously.

A 100-shot cake with 12mm tubes fires a hundred small, quick bursts, thin comets and crackles, over 30 or 40 seconds. It’s fun, fast and cheap. A 25-shot cake with 30mm tubes fires 25 bursts that open into full spheres of colour fifty metres across, with the report echoing off the houses. Same category of product, completely different experience. The 25-shot will cost more and be worth it.

So when you compare two cakes, look past the shot count to the calibre.

Tube size: where the impact comes from

Calibre is the internal diameter of each tube, quoted in millimeters. As a rough guide:

• 12mm to 16mm: small garden effects. Low height, tight bursts, plenty of crackles and whistle. Great as fillers between bigger pieces.
• 20mm: the standard F2 garden cake. Decent height, proper coloured bursts, still legal at 8 meters.
• 25mm: the point where cakes start to look like a display. Usually F3, 25 meters, with bursts that spread wide.
• 30mm: the top end of consumer cakes. Big, heavy stars, brocade crowns that hang in the air, and a report you feel in your chest.

The size of the burst scales with the tube because a bigger tube holds a bigger shell, and a bigger shell carries more stars and more break charge. That’s physics, not marketing.

Powder weight: the honest measure

Where a retailer lists it, the net explosive content (NEC) in grams tells you how much pyrotechnic composition the cake contains. Two cakes with identical shot counts can have NEC figures that differ by a factor of three. The one with more powder will fire higher, break bigger and last longer in the sky.

A rough rule for garden cakes: under 200g is a modest F2, 200 to 500g is a strong F2 or entry F3, and anything from 500g up to the consumer limit is proper display material. Our 1.3G category is essentially a filter for the heavier end of this scale; 1.3G is a transport classification that applies to fireworks with more powder per unit, and it’s where the big cakes live.

Effects: what’s in the tubes

The label and the product video will name the effects, and it helps to know the vocabulary.

Peony: a round burst of coloured stars, the classic firework shape. Chrysanthemum: the same but with each star leaving a trail. Willow: long golden trails that droop and hang. Brocade or brocade crown: a dense gold burst with glittering, slow-falling tails, usually the last thing you see in a finale. Crackling: a burst that breaks into hundreds of tiny popping sparks. Strobe: stars that flash on and off. Comet: a rising tail without a burst. Mine: an effect that fires upward from ground level as a spray. Crossette: stars that split into four mid-air. Dahlia: fewer but much bigger stars. Palm: thick rising trails that fan out like a tree. Time rain: falling gold glitter that lingers. Whistle and hummer: noise effects.

A well-designed cake mixes these so that the sequence has a shape. A cheap cake fires the same effect 36 times. The video will tell you which is which within ten seconds.

Firing pattern: straight, fanned or mixed

Straight-firing cakes put every shot into a vertical column. They look tall and concentrated. Fanned cakes tilt the tubes so the sequence sweeps left to right (a Z-fire) or in a W shape, spreading the effects across the sky. From the audience’s point of view a fanned cake looks bigger and more expensive than a straight one with the same powder, because it fills more of their field of view. Mixed cakes do both.

If you have room to fire only one big cake, a fanned 25-shot in 25mm or 30mm gives more visual impact per pound than almost anything else in the shop.

Noise: impact of a different kind

Cakes are usually rated 1 to 5 for noise. A 5 means titanium salutes and reports that echo across a valley. Many customers want that on Bonfire Night. Many don’t, and it’s worth saying that low noise and low impact are not the same thing. A crackling willow cake rated 2 can be one of the most beautiful pieces in a show. Our silent and low-noise range has full-size cakes with 25mm and 30mm tubes that keep the bursts and drop the bang, which is what you want near horses, hospitals, care homes or a neighbour’s newborn.

Category and distance

Whatever the numbers say, the category on the label decides where you can use it. F2 needs 8 metres between the cake and every spectator. F3 needs 25 meters. Measure it. A 25mm cake that looks tempting online is no use at all if you can’t legally stand far enough back from it in your garden.

Reading a listing in thirty seconds

Here’s how we’d assess a cake we’d never seen before. Look at the calibre first: 20mm is garden, 25mm and above is display. Then the category: does your space allow it? Then the NEC if listed. Then the firing pattern: fanned for width, straight for height. Then the duration and the video, to judge the pacing. Then the noise rating. Then the price. Doing it in that order stops you buying on shot count and price alone, which is how people end up with a 100-shot cake that fizzes for 40 seconds and leaves everyone underwhelmed.

The other common mistake is buying every cake at the same calibre. A show made entirely of 20mm cakes has no shape; a show made entirely of 30mm cakes is exhausting and expensive. Mix them and keep the biggest for last.

Setting up for maximum effect

A cake fires better and safer when it’s braced upright on flat ground. Bricks around the base or stakes and tape are plenty. Keep the fuse accessible, light with a portfire at arm’s length, and retreat. Fire fanned cakes side-on to the audience so they see the full sweep. Fire straight cakes with a clear sky above; overhanging trees will catch stars.

Where the good cakes are

All of the cakes in our Barrages and Cakes range list the category, calibre, shots and duration, and everyone has a video. We stock the big UK brands alongside our own Big Shotter range, which we design to hit hard on the calibre and NEC figures rather than pad the shot count. You can order online with insured UK delivery or come to the shop in Bradford and hold the boxes, which is still the best way to feel the difference between a 20mm cake and a 30mm one.