Which Weapons Are Worth Investing In?
Spirhalite Shards are the scarcest thing you farm, and weapon upgrades do not transfer. Where they should go, which weapons carry deep Bottomless Buffet floors, and the traps players have already fallen into. Sources read 2026-08-06.
By the SplatAtlas editorial team · Last updated: 2026-08-06
Weapon upgrading looks like a simple menu: pay Spirhalite Shards, watch the damage number climb. The catch is on the price tag. Costs scale hard with level: the official screenshot in our weapons guide shows a level-21 weapon asking 2,836 shards for three levels, and every shard you spend is welded to that one weapon. There is no respec and no refund beyond scrapping.
That makes "which weapon" a bigger decision than "how much". This page is the investment answer in four parts: what to upgrade first, which specific weapons deserve shards, how large the Primo gap really is in measured numbers, and the traps, including one player's over-investment story that is worth more than any tier list.
What Should You Upgrade First?
GameWith's investment-priority guide (updated August 6) puts your resources in this order. It is a late-game order, and here is the reasoning for each row:
| Priority | Invest in | Why this rank |
|---|---|---|
| 1 | Weapons | Hunt ★5 and Primo (絶品) copies of the top-ranked weapons and collect Weapon Powers along the way. Once ★5s drop, this is the biggest damage lever in the game. |
| 2 | Tank upgrades | Attack-up nodes first: they multiply every weapon you will ever hold, but per point they move less than a good weapon does. |
| 3 | Gadget development | New gadgets unlock whole build archetypes (the freeze meta runs on them; see the builds guide). |
| 4 | Gadget parts | Parts tune gadgets you already own. Strong, but a refinement of rank 3 rather than a new capability. |
| 5 | Hideout Ship facilities | Unlocks and conveniences. Build the upgrade and scrapping facilities early, then let this rank wait. |
| 6 | Partner bonds | GameWith's order within the rank: Big Man (マンタロー) first for his broadly useful Showstopper, then Frye (ウツホ) for crowd-clearing. |
One caveat that keeps this honest: early in the story, Game8's advice, recorded in our weapons guide, is the reverse, tank and gadgets before weapons, because pre-★5 weapons get replaced anyway. The two sources do not actually disagree: both mean "do not pour shards into anything below ★5". Weapons jump to rank 1 the day ★5 and Primo drops start arriving.
Which Specific Weapons Deserve Your Shards?
The current consensus of Game8 JP (August 6) and GameWith (August 5) rankings, read side by side on August 6. The pattern behind the list: one-big-hit classes, meaning Splatanas, Brellas, Stringers, Blasters and Chargers, pay off the Ice Breaker freeze multiplier, because the whole multiplied payload lands in one swing. Rapid-hit classes (Shooters, Splatlings, Brushes) spend the same multiplier on one small pellet and never scale the same way.
| Weapon | Class | Why it earns shards |
|---|---|---|
| Thermal Brella (シートシェルターサーモ) | Brella | Simultaneous pellets that all land inside one Ice Breaker window: the top of both rankings. |
| Alpine Stringer (アルペンストリンガー) | Stringer | The same simultaneous-hit logic as the Brella, delivered from range. |
| Butane Blaster (プロパンブラスター) | Blaster | The fast-firing one-big-hit pick; the speed spec makes it the most forgiving of the list. |
| Toy-Shark Blaster (トイブラスターシャーク) | Blaster | Long-range blasts: the same burst damage with more standoff distance. |
| Rail Splatana (レールワイパー) | Splatana | The freeze-meta headliner from our builds guide; its Primo fronts two of the three databases. |
| High-Octane 4K (ハイオク4K) | Charger | The deep-floor specialist: the weapon behind the deepest Bottomless Buffet run we have seen reported (floor 802). |
One rule from the players who have actually climbed deep: the specialisation tag matters as much as the weapon name. The Bahamut climber who reached floor 550 (July–August) poured everything into a swing-speed-spec Primo Engine Roller (絶品エンジンローラー), which carried him to floor 400, then rebuilt around a charge-speed-spec Primo freeze charger for the floors past that. Chargers are the most common pick past floor 700, though as of 2026-08-14 they are no longer the only one: a stringer cleared 800–802 and an Engine Roller reached 700. A Primo of the right weapon with the wrong spec is, in their words and in practice, not the same weapon. Check the tag before the first shard goes in.
How Much Stronger Is a Primo, Really?
The most useful numbers we have come from one Taiwanese player's controlled tests, posted on the Bahamut forum between July 26 and August 3. These are community measurements, not lab data, so treat them as such. First finding: weapon level raises base damage only. On their test weapon, one level moved base damage 2,685 → 2,781, a steady linear climb, with no hidden stats attached.
Second finding: a base weapon and its Primo share the same base stats at the same level. What the Primo adds is the extreme version of the specialisation. In their 3-second DPS test on a level-50 Water-Wing Splattershot Jr. (ぷかぷかシューター), the base weapon dealt roughly 180,000 damage and the Primo roughly 250,000, about +39% from the specialisation alone, at identical level and identical base damage.
The investment reading: levels are the floor, the Primo spec is the multiplier. A normal ★5 at high level will always lose to the same weapon's Primo at the same level, and no amount of shards closes that gap, which is exactly how the lock-in trap below happens.
What Are the Investment Traps?
Three ways to waste shards that players have already documented, so you do not have to rediscover them:
Over-investing in a normal (non-Primo) weapon
A Bahamut poster (qw12366, July 28) levelled a normal stringer-class weapon deep into the shard curve and described themselves as locked in: the sunk shards made switching feel impossible, but the weapon had a hard ceiling a Primo does not. Their fix, in their own words: scrap everything that is not a ★5 Primo and feed the main weapon. They reported a clear DPS jump immediately after. Normal ★5s are fine to use; they are not fine to max.
Slotting Concentrated Attack on a multi-hit build
Concentrated Attack (集中攻撃) counts consecutive hits on ONE target, and any damage that touches another Salmonid, including your own AoE and gadget ticks, resets the count. Two independent community sources (a bilibili commenter and a Bahamut poster, August 2) confirmed the reset. It looks strong on paper and does nothing on the AoE-heavy builds most players actually run. Single-target weapons only.
The wrong-spec Primo
Primo drops are random, and the third axis (ink / range / speed) is fixed per weapon name in the catalogue, but the deep-floor players treat spec as part of the weapon's identity when choosing what to invest in. A big-hit weapon whose spec does not serve its burst (see the spec rule above) will eat the same shards and return less. If the tag is wrong for the job, keep farming.
How Do You Feed Your Main Weapon?
The loop GameWith recommends, which is also exactly the recovery the locked-in player used:
- Pick one weapon from the consensus list (or your class's equivalent) in its ★5 Primo form with the right spec tag. That is "the main". Everything else exists to feed it.
- Keep climbing the Bottomless Buffet and running Super Spicy dungeons: ★5 and Primo drops come from progression, not from a dedicated farm. Routes are in the farming guide.
- Scrap every duplicate and every ★4-and-below drop: a ★5 returns 9 Weapon Power Shards, a ★4 returns 4. High-rarity junk is the efficient scrap, not stacks of ★1s.
- Spend Weapon Power Shards on damage powers first, which is GameWith's explicit priority, and remember only ★5 weapons can have powers swapped at the post-story facility.
- Bank Spirhalite Shards and buy weapon levels in blocks on the main, not one level at a time across five weapons.
The shape of the whole page in one sentence: many weapons drop, one weapon gets fed. What you put ON that weapon is the builds guide's territory; the full ranking lives in the best-weapons guide.
Weapon Investment FAQ
Should I upgrade weapons before my tank?
Not at first. During the story, tank attack nodes and gadget development pay more because pre-★5 weapons get replaced. Once ★5 and Primo drops start, weapons move to the top of the list. That is GameWith's current priority order, and the two sources agree on the underlying rule: never pour shards into anything below ★5.
Is a Primo really worth chasing over a normal ★5?
By the only measured numbers we have, one Taiwanese player's controlled test, yes. At the same level and identical base damage, the Primo of the same weapon dealt about 39% more damage over a 3-second burst, purely from its extreme specialisation. A normal ★5 is a bridge; a Primo with the right spec is the destination.
Which single weapon should get my shards first?
The one from the consensus list that matches how you play: Thermal Brella or Alpine Stringer for simultaneous-hit burst, Butane Blaster or Toy-Shark Blaster for blast damage, Rail Splatana for the freeze meta, High-Octane 4K for deep-floor charging. In its ★5 Primo form, with the right spec tag. Both conditions, not either.
What should I do with duplicate weapons?
Scrap them. A ★5 scraps into 9 Weapon Power Shards and a ★4 into 4, and those shards are how you re-roll and level the powers on the weapon you keep. The recovery that worked for the over-invested player was exactly this: scrap everything that is not a ★5 Primo and feed the main.
Related guides
Sources
- 育成と強化のおすすめ優先度, GameWith (Japan)
- 最強武器ランキング, GameWith (Japan)
- 最強武器ランキング, Game8 (Japan)
- 武器強化與絕品實測討論串 (BANANAww), 巴哈姆特 (Bahamut forum, community)
- 一般武器過度投資的教訓串 (qw12366), 巴哈姆特 (Bahamut forum, community)
- 無限食堂700層攻略串 (我愛數學), 巴哈姆特 (Bahamut forum, community)
- 【涂击队】无限食堂-弓 800~802 (啦一啦一啦), bilibili (community video)
- 【引擎滚筒】700层无限食堂 飞天轮椅走地鸡 敲冰棍 (WaterStone_Y), bilibili (community video)
Priority order: GameWith 育成と強化のおすすめ優先度 (updated 2026-08-06). Weapon consensus: Game8 JP (2026-08-06) × GameWith (2026-08-05) rankings, read 2026-08-06. Damage measurements, the +39% base-vs-Primo test, the lock-in account and the deep-floor spec rule: Bahamut forum posts (2026-07-26 → 08-03), community-reported single-player tests, labelled as such throughout. The Concentrated Attack reset is confirmed by two independent community sources (2026-08-02). Note: some EN outlets print contradictory Primo level caps ("ten levels", allthings.how 07-25; "indefinitely", Nintendo Life 07-27); JP sources and the measured data support the ★5 level-100 model in our weapons database.