The Ranger I DM asked me if he would be able to Cast Lightning Arrow, then use the arrow as ammunition for Conjure Barrage.
Lightning Arrow - Casting Time: 1 bonus action - Duration: Concentration, up to 1 minute
The next time you make a ranged weapon attack during the spell’s duration, the weapon’s ammunition, or the weapon itself if it’s a thrown weapon, transforms into a bolt o f lightning. Make the attack roll as normal. The target takes 4d8 lightning damage on a hit, or half as much damage on a miss, instead o f the weapon’s normal damage. Whether you hit or miss, each creature within 10 feet o f the target must make a Dexterity saving throw. Each o f these creatures takes 2d8 lightning damage on a failed save, or half as much damage on a successful one. The piece o f ammunition or weapon then returns to its normal form. At Higher Levels. When you cast this spell using a spell slot o f 4th level or higher, the damage for both effects o f the spell increases. -PHB 255
Conjure Barrage - Casting Time: 1 action - Duration: Instantaneous
You throw a nonmagical weapon or fire a piece of nonmagical ammunition into the air to create a cone of identical weapons that shoot forward and then disappear. Each creature in a 60-foot cone must succeed on a Dexterity saving throw. A creature takes 3d8 damage on a failed save, or half as much damage on a successful one. The damage type is the same as that of the weapon or ammunition used as a component. -PHB 225
Now on Page 202 it states:
A spell cast with a bonus action is especially swift. You must use a bonus action on your turn to cast the spell, provided that you haven’t already taken a bonus action this turn. You can’t cast another spell during the same turn, except for a cantrip with a casting time of 1 action.
But then on the next page, 203 it also states:
Normal activity, such as moving and attacking, doesn’t interfere with concentration. The following factors can break concentration:
- Casting another spell that requires concentration. You lose concentration on a spell if you cast another spell that requires concentration. You can’t concentrate on two spells at once.
So, would he be able to cast both in the same turn? I interpret the last quote meaning that you can do 2 spells, if 1 is concentration and the other is not, unless a spell doesn't count as an attack. If he can't use them in the same round, could he cast Lightning Arrow, save it until the next round, then use it for Conjure Barrage?