diff --git a/src/dux/weapons/rules.js b/src/dux/weapons/rules.js
deleted file mode 100644
index 52d0633..0000000
--- a/src/dux/weapons/rules.js
+++ /dev/null
@@ -1,9 +0,0 @@
-
-
-const is_broadside = arcs => {
-    if( arcs.length !== 4 ) return false;
-
-    // that'd be A or F
-    return !arcs.some( a => a.length === 1 );
-}
-
diff --git a/src/lib/components/ShipEdit/Weaponry/Weapon/Beam/index.svelte b/src/lib/components/ShipEdit/Weaponry/Weapon/Beam/index.svelte
new file mode 100644
index 0000000..8e031d3
--- /dev/null
+++ b/src/lib/components/ShipEdit/Weaponry/Weapon/Beam/index.svelte
@@ -0,0 +1,83 @@
+<label>beam</label>
+
+<Field label="beam class">
+    <select bind:value={weaponClass}>
+        <option value={1}>1</option>
+        <option value={2}>2</option>
+        <option value={3}>3</option>
+        <option value={4}>4</option>
+    </select>
+</Field>
+
+<Field label="arcs">
+    <select bind:value={nbrArcs}>
+        {#each arc_options[weaponClass] || [] as nbrArcs (nbrArcs)}
+            <option>{nbrArcs}</option>
+        {/each}
+    </select>
+</Field>
+
+<Arcs selected={arcs} on:click_arc={({ detail }) => setArcs(detail)} />
+
+<script>
+    import { getContext } from "svelte";
+
+    import Arcs from "../Arcs.svelte";
+    import ShipItem from "$lib/components/ShipItem/index.svelte";
+    import Field from "$lib/components/Field/index.svelte";
+
+    import { createEventDispatcher } from "svelte";
+
+    const all_arcs = ["FS", "F", "FP", "AP", "A", "AS"];
+
+    export let weaponClass = 1;
+    export let arcs = ["F"];
+
+    let arc_options = {
+        1: [6],
+        2: [3, 6],
+        3: [1, 2, 3, 4, 5, 6, "broadside"],
+        4: [1, 2, 3, 4, 5, 6, "broadside"],
+    };
+
+    $: arcsCaches = arcs.join(',');
+
+    let nbrArcs = arcs.length;
+
+    $: if (!arc_options[weaponClass].includes(nbrArcs)) {
+        nbrArcs = arc_options[weaponClass][0];
+        console.log({nbrArcs, label:"in if"})
+    }
+
+    const broadside = ["FS", "FP", "AP", "AS"];
+
+
+    function setArcs(firstArc) {
+        console.log(firstArc);
+        if (nbrArcs === "broadside") {
+            arcs = broadside;
+            return;
+        }
+            let first_index = all_arcs.findIndex((arc) =>  arc === firstArc);
+            if (first_index === -1) first_index = 0;
+
+        console.log({arcs, label:"before"});
+            arcs = _.range(nbrArcs).map(
+                (i) => all_arcs[(first_index + i) % all_arcs.length]
+            );
+        arcsCaches = arcs.join(',');
+        console.log({arcs, label:"after"});
+    }
+
+    $: if (arcs.length !== nbrArcs) setArcs(arcs[0]);
+
+    $: console.log("it changed!", arcs)
+    $: console.log("it changed!", arcsCaches)
+
+    const dispatch = createEventDispatcher();
+
+    $: dispatch("change", {
+            weaponClass,
+            arcs: arcsCaches.split(','),
+        });
+</script>
diff --git a/src/lib/components/ShipEdit/Weaponry/Weapon/index.svelte b/src/lib/components/ShipEdit/Weaponry/Weapon/index.svelte
index 17081d3..dc8965a 100644
--- a/src/lib/components/ShipEdit/Weaponry/Weapon/index.svelte
+++ b/src/lib/components/ShipEdit/Weaponry/Weapon/index.svelte
@@ -19,14 +19,14 @@
   import Arc from "./Arc.svelte";
   import ShipItem from "$lib/components/ShipItem/index.svelte";
   import Field from "$lib/components/Field/index.svelte";
-  /* import Beam from "./Beam/index.svelte"; */
+   import Beam from "./Beam/index.svelte";
    import Submunition from "./Submunition.svelte";
    import PointDefenceSystem from "./PDS.svelte";
    import Scattergun from "./Scattergun.svelte";
   import Needle from "./Needle.svelte";
 
   const component = {
-    /* beam: Beam, */
+     beam: Beam,
      submunition: Submunition,
      pds: PointDefenceSystem,
      scattergun: Scattergun,
@@ -41,10 +41,10 @@
 
   $: type = weapon.type;
 
-  $: console.log(weapon);
   const remove = () => ship.dispatch.removeWeapon(id);
 
   const update = ({ detail }) => {
+      console.log({id,type})
     ship.dispatch.setWeapon({
       id,
       type,
diff --git a/src/lib/components/ShipEdit/Weaponry/Weaponry.stories.svelte b/src/lib/components/ShipEdit/Weaponry/Weaponry.stories.svelte
index 35be883..4072200 100644
--- a/src/lib/components/ShipEdit/Weaponry/Weaponry.stories.svelte
+++ b/src/lib/components/ShipEdit/Weaponry/Weaponry.stories.svelte
@@ -21,6 +21,7 @@ import { readable, get, derived } from "svelte/store";
   const store = weaponryDux.createStore();
   const state = readable(store.getState(), (set) => {
     store.subscribe(() => {
+          console.log(store.getState());
       set(store.getState());
     });
   });
diff --git a/src/lib/shipDux/weaponry/weapons.js b/src/lib/shipDux/weaponry/weapons.js
index 2ecb71b..6aa6167 100644
--- a/src/lib/shipDux/weaponry/weapons.js
+++ b/src/lib/shipDux/weaponry/weapons.js
@@ -4,7 +4,9 @@ import u from "updeep";
 const reqs = { cost: 0, mass: 0 };
 
 export const weaponTypes = [
-    { name: 'beam', type: 'beam', reqs: beam_cost_mass },
+    { name: 'beam', type: 'beam', reqs: beam_cost_mass, initial: {
+        weaponClass: 1
+    }},
     { name: 'submunition pack', type: 'submunition', reqs: { mass:1, cost:3 },
         initial: { arc: 'F' }
     },
@@ -23,8 +25,20 @@ const dux = new Updux({
     },
 });
 
-dux.setMutation('setWeapon', ({id,...rest}) =>
-    u.map( u.if( (w) => w.id === id, { ...rest }))
+dux.setMutation('setWeapon', ({id,...rest}) => state => {
+console.log(id,rest,state);
+    state = u.map( u.if( (w) => w.id === id,
+        weapon => {
+            return {
+                id,
+                ...rest,
+                reqs: weaponReqs(rest),
+            }
+        } ), state );
+    console.log(state);
+    return state;
+
+}
 );
 
 dux.setMutation('removeWeapon', id => state => [
@@ -32,13 +46,14 @@ dux.setMutation('removeWeapon', id => state => [
 ]);
 
 dux.setMutation('addWeapon', type => state => {
+    const initial = weaponTypes.find(w => w.type === type ).initial;
     return [
         ...state,
         {
             id: state.length === 0 ? 1 : state[state.length -1]+1,
             type,
-            reqs: weaponReqs({type}),
-            ...weaponTypes.find(w => w.type === type ).initial,
+            reqs: weaponReqs({type,...initial}),
+            ...initial,
         }
     ]
 });
@@ -54,21 +69,30 @@ function weaponReqs(weapon) {
     return reqs;
 }
 
-function beam_cost_mass({weapon_class, arcs}) {
+const isBroadside = arcs => {
+    if( arcs.length !== 4 ) return false;
+
+    // that'd be A or F
+    return !arcs.some( a => a.length === 1 );
+}
+
+function beam_cost_mass({weaponClass, arcs}) {
+    console.log({weaponClass,arcs})
     let mass;
-    if( weapon_class === 1 ) {
+
+    if( weaponClass === 1 ) {
         mass = 1;
     }
 
-    if( weapon_class == 2 ) {
+    if( weaponClass === 2 ) {
         mass = 2 + (arcs.length > 3 ? 1 : 0);
     }
 
 
-    if( weapon_class == 3 ) {
+    if( weaponClass == 3 ) {
         mass = 4;
 
-        if( is_broadside(arcs) ) {
+        if( isBroadside(arcs) ) {
             mass += 2;
         }
         else {
@@ -76,10 +100,10 @@ function beam_cost_mass({weapon_class, arcs}) {
         }
     }
 
-    if( weapon_class == 4 ) {
+    if( weaponClass == 4 ) {
         mass = 8;
 
-        if( is_broadside(arcs) ) {
+        if( isBroadside(arcs) ) {
             mass += 4;
         }
         else {