diff --git a/PKHeX.Core/Saves/Substructures/Gen5/Encount5.cs b/PKHeX.Core/Saves/Substructures/Gen5/Encount5.cs
index adccff1af..f1d9b9d77 100644
--- a/PKHeX.Core/Saves/Substructures/Gen5/Encount5.cs
+++ b/PKHeX.Core/Saves/Substructures/Gen5/Encount5.cs
@@ -1,23 +1,16 @@
-using System;
-
-namespace PKHeX.Core
+namespace PKHeX.Core
 {
     public abstract class Encount5 : SaveBlock
     {
         protected Encount5(SAV5 SAV, int offset) : base(SAV) => Offset = offset;
 
-        public abstract uint SwarmSeed { get; set; }
+        public abstract byte SwarmSeed { get; set; }
         public abstract uint SwarmMaxCountModulo { get; }
 
         public uint SwarmIndex
         {
             get => SwarmSeed % SwarmMaxCountModulo;
-            set
-            {
-                value %= SwarmMaxCountModulo;
-                while (SwarmIndex != value)
-                    ++SwarmSeed;
-            }
+            set => SwarmSeed = (byte)(value % SwarmMaxCountModulo);
         }
     }
 
@@ -25,7 +18,7 @@ namespace PKHeX.Core
     {
         public Encount5BW(SAV5BW SAV, int offset) : base(SAV, offset) { }
 
-        public override uint SwarmSeed { get => BitConverter.ToUInt32(Data, Offset + 0x30); set => BitConverter.GetBytes(value).CopyTo(Data, Offset + 0x30); }
+        public override byte SwarmSeed { get => Data[Offset + 0x30]; set => Data[Offset + 0x30] = value; }
         public override uint SwarmMaxCountModulo => 17;
     }
 
@@ -33,7 +26,7 @@ namespace PKHeX.Core
     {
         public Encount5B2W2(SAV5B2W2 SAV, int offset) : base(SAV, offset) { }
 
-        public override uint SwarmSeed { get => BitConverter.ToUInt32(Data, Offset + 0x2C); set => BitConverter.GetBytes(value).CopyTo(Data, Offset + 0x2C); }
+        public override byte SwarmSeed { get => Data[Offset + 0x2C]; set => Data[Offset + 0x2C] = value; }
         public override uint SwarmMaxCountModulo => 19;
     }
 }