diff --git a/src/SharpCompress/Archives/Rar/RarArchive.cs b/src/SharpCompress/Archives/Rar/RarArchive.cs
index 699073cb..fb052c37 100644
--- a/src/SharpCompress/Archives/Rar/RarArchive.cs
+++ b/src/SharpCompress/Archives/Rar/RarArchive.cs
@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -12,7 +13,8 @@ namespace SharpCompress.Archives.Rar
 {
     public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
     {
-        internal IRarUnpack Unpack { get; }
+        internal Lazy<IRarUnpack> UnpackV2017 { get; } = new Lazy<IRarUnpack>(() => new SharpCompress.Compressors.Rar.UnpackV2017.Unpack());
+        internal Lazy<IRarUnpack> UnpackV1 { get; } = new Lazy<IRarUnpack>(() => new SharpCompress.Compressors.Rar.UnpackV1.Unpack());
 
 #if !NO_FILE
 
@@ -24,11 +26,6 @@ namespace SharpCompress.Archives.Rar
         internal RarArchive(FileInfo fileInfo, ReaderOptions options)
             : base(ArchiveType.Rar, fileInfo, options)
         {
-#if !RarV2017_USELEGACY
-            Unpack = new SharpCompress.Compressors.Rar.UnpackV2017.Unpack();
-#else
-            Unpack = new SharpCompress.Compressors.Rar.UnpackV1.Unpack();
-#endif
         }
 
         protected override IEnumerable<RarVolume> LoadVolumes(FileInfo file)
@@ -45,11 +42,6 @@ namespace SharpCompress.Archives.Rar
         internal RarArchive(IEnumerable<Stream> streams, ReaderOptions options)
             : base(ArchiveType.Rar, streams, options)
         {
-#if !RarV2017_USELEGACY
-            Unpack = new SharpCompress.Compressors.Rar.UnpackV2017.Unpack();
-#else
-            Unpack = new SharpCompress.Compressors.Rar.UnpackV1.Unpack();
-#endif
         }
 
         protected override IEnumerable<RarArchiveEntry> LoadEntries(IEnumerable<RarVolume> volumes)
diff --git a/src/SharpCompress/Archives/Rar/RarArchiveEntry.cs b/src/SharpCompress/Archives/Rar/RarArchiveEntry.cs
index 064dcf7a..60ece4ee 100644
--- a/src/SharpCompress/Archives/Rar/RarArchiveEntry.cs
+++ b/src/SharpCompress/Archives/Rar/RarArchiveEntry.cs
@@ -51,7 +51,7 @@ namespace SharpCompress.Archives.Rar
             get
             {
                 CheckIncomplete();
-                return parts.Aggregate(0L, (total, fp) => { return total + fp.FileHeader.CompressedSize; });
+                return parts.Aggregate(0L, (total, fp) => total + fp.FileHeader.CompressedSize);
             }
         }
 
@@ -61,7 +61,13 @@ namespace SharpCompress.Archives.Rar
             {
                 throw new InvalidOperationException("Use ExtractAllEntries to extract SOLID archives.");
             }
-            return new RarStream(archive.Unpack, FileHeader, new MultiVolumeReadOnlyStream(Parts.Cast<RarFilePart>(), archive));
+
+            if (IsRarV3)
+            {
+                return new RarStream(archive.UnpackV1.Value, FileHeader, new MultiVolumeReadOnlyStream(Parts.Cast<RarFilePart>(), archive));
+            }
+            
+            return new RarStream(archive.UnpackV2017.Value, FileHeader, new MultiVolumeReadOnlyStream(Parts.Cast<RarFilePart>(), archive));
         }
 
         public bool IsComplete 
diff --git a/src/SharpCompress/Common/Rar/Headers/MarkHeader.cs b/src/SharpCompress/Common/Rar/Headers/MarkHeader.cs
index 4e972913..c7b94149 100644
--- a/src/SharpCompress/Common/Rar/Headers/MarkHeader.cs
+++ b/src/SharpCompress/Common/Rar/Headers/MarkHeader.cs
@@ -67,10 +67,6 @@ namespace SharpCompress.Common.Rar.Headers
                             {
                                 return new MarkHeader(false); // Rar4
                             } 
-                            else 
-                            {
-                                continue;
-                            }
                         } 
                         else if (b == 0x45) 
                         {
@@ -80,19 +76,11 @@ namespace SharpCompress.Common.Rar.Headers
                             if (b != 0x5e) continue;
                             throw new InvalidFormatException("Rar format version pre-4 is unsupported.");
                         } 
-                        else 
-                        {
-                            continue;
-                        }
                     } 
                     else 
                     {
                         b = GetByte(stream); start++;
-                        continue;
                     }
-
-                    // unreachable
-                    throw new InvalidOperationException();
                 }
             }
             catch (Exception e)
diff --git a/src/SharpCompress/Common/Rar/RarEntry.cs b/src/SharpCompress/Common/Rar/RarEntry.cs
index cec1eb44..85be0bb3 100644
--- a/src/SharpCompress/Common/Rar/RarEntry.cs
+++ b/src/SharpCompress/Common/Rar/RarEntry.cs
@@ -7,6 +7,11 @@ namespace SharpCompress.Common.Rar
     {
         internal abstract FileHeader FileHeader { get; }
 
+        /// <summary>
+        /// As the V2017 port isn't complete, add this check to use the legacy Rar code.
+        /// </summary>
+        internal bool IsRarV3 => FileHeader.CompressionAlgorithm == 29 || FileHeader.CompressionAlgorithm == 36;
+        
         /// <summary>
         /// The File's 32 bit CRC Hash
         /// </summary>
diff --git a/src/SharpCompress/Compressors/Rar/UnpackV1/UnpackInline.cs b/src/SharpCompress/Compressors/Rar/UnpackV1/UnpackInline.cs
index e5ca5b1e..35b65eb7 100644
--- a/src/SharpCompress/Compressors/Rar/UnpackV1/UnpackInline.cs
+++ b/src/SharpCompress/Compressors/Rar/UnpackV1/UnpackInline.cs
@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
+
 namespace SharpCompress.Compressors.Rar.UnpackV1
 {
     internal partial class Unpack
diff --git a/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack30_cpp.cs b/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack30_cpp.cs
index 8ec81763..7e77c7d4 100644
--- a/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack30_cpp.cs
+++ b/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack30_cpp.cs
@@ -13,7 +13,7 @@ using System;
 using static SharpCompress.Compressors.Rar.UnpackV2017.PackDef;
 using static SharpCompress.Compressors.Rar.UnpackV2017.UnpackGlobal;
 //using static SharpCompress.Compressors.Rar.UnpackV2017.Unpack.Unpack30Local;
-
+/*
 namespace SharpCompress.Compressors.Rar.UnpackV2017
 {
     internal partial class Unpack
@@ -797,3 +797,4 @@ void InitFilters30(bool Solid)
 
     }
 }
+*/
\ No newline at end of file
diff --git a/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack_cpp.cs b/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack_cpp.cs
index 0fa14295..44abffa3 100644
--- a/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack_cpp.cs
+++ b/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack_cpp.cs
@@ -167,7 +167,7 @@ void DoUnpack(uint Method,bool Solid)
 #if !RarV2017_RAR5ONLY
     case 29: // rar 3.x compression
       if (!Fragmented)
-        Unpack29(Solid);
+        throw new NotImplementedException();
       break;
 #endif
     case 50: // RAR 5.0 compression algorithm.
@@ -225,7 +225,7 @@ void UnpInitData(bool Solid)
 #if !RarV2017_SFX_MODULE
   UnpInitData20(Solid);
 #endif
-  UnpInitData30(Solid);
+  //UnpInitData30(Solid);
   UnpInitData50(Solid);
 }
 
diff --git a/src/SharpCompress/Compressors/Rar/UnpackV2017/unpack_hpp.cs b/src/SharpCompress/Compressors/Rar/UnpackV2017/unpack_hpp.cs
index afea642c..06520ab5 100644
--- a/src/SharpCompress/Compressors/Rar/UnpackV2017/unpack_hpp.cs
+++ b/src/SharpCompress/Compressors/Rar/UnpackV2017/unpack_hpp.cs
@@ -196,9 +196,9 @@ class UnpackFilter30
   // in PrgStack array. Not defined for filters in Filters array.
   public uint ParentFilter;
 
-#if !RarV2017_RAR5ONLY
+/*#if !RarV2017_RAR5ONLY
   public VM_PreparedProgram Prg;
-#endif
+#endif*/
 };
 
 
@@ -374,9 +374,9 @@ internal partial class Unpack
 
     int PrevLowDist,LowDistRepCount;
 
-#if !RarV2017_RAR5ONLY
+/*#if !RarV2017_RAR5ONLY
     ModelPPM PPM;
-#endif
+#endif*/
     int PPMEscChar;
 
     readonly byte [] UnpOldTable = new byte[HUFF_TABLE_SIZE30];
@@ -390,9 +390,9 @@ internal partial class Unpack
     bool TablesRead2,TablesRead3,TablesRead5;
 
     // Virtual machine to execute filters code.
-#if !RarV2017_RAR5ONLY
+/*#if !RarV2017_RAR5ONLY
     RarVM VM;
-#endif
+#endif*/
   
     // Buffer to read VM filters code. We moved it here from AddVMCode
     // function to reduce time spent in BitInput constructor.
diff --git a/src/SharpCompress/Readers/Rar/RarReader.cs b/src/SharpCompress/Readers/Rar/RarReader.cs
index 71fe260c..05fe0daa 100644
--- a/src/SharpCompress/Readers/Rar/RarReader.cs
+++ b/src/SharpCompress/Readers/Rar/RarReader.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using SharpCompress.Common;
@@ -13,16 +14,12 @@ namespace SharpCompress.Readers.Rar
     public abstract class RarReader : AbstractReader<RarReaderEntry, RarVolume>
     {
         private RarVolume volume;
-        private readonly IRarUnpack pack;
+        internal Lazy<IRarUnpack> UnpackV2017 { get; } = new Lazy<IRarUnpack>(() => new SharpCompress.Compressors.Rar.UnpackV2017.Unpack());
+        internal Lazy<IRarUnpack> UnpackV1 { get; } = new Lazy<IRarUnpack>(() => new SharpCompress.Compressors.Rar.UnpackV1.Unpack());
 
         internal RarReader(ReaderOptions options)
             : base(options, ArchiveType.Rar)
         {
-#if !RarV2017_USELEGACY
-            this.pack = new SharpCompress.Compressors.Rar.UnpackV2017.Unpack();
-#else
-            this.pack = new SharpCompress.Compressors.Rar.UnpackV1.Unpack();
-#endif
         }
 
         internal abstract void ValidateArchive(RarVolume archive);
@@ -68,9 +65,14 @@ namespace SharpCompress.Readers.Rar
             return Entry.Parts;
         }
 
-        protected override EntryStream GetEntryStream() {
+        protected override EntryStream GetEntryStream() 
+        {
             var stream = new MultiVolumeReadOnlyStream(CreateFilePartEnumerableForCurrentEntry().Cast<RarFilePart>(), this);
-            return CreateEntryStream(new RarCrcStream(pack, Entry.FileHeader, stream));
+            if (Entry.IsRarV3)
+            {
+                return CreateEntryStream(new RarCrcStream(UnpackV1.Value, Entry.FileHeader, stream));
+            }
+            return CreateEntryStream(new RarCrcStream(UnpackV2017.Value, Entry.FileHeader, stream));
         }
     }
 }
diff --git a/src/SharpCompress/SharpCompress.csproj b/src/SharpCompress/SharpCompress.csproj
index 5c1d0815..a20a92a9 100644
--- a/src/SharpCompress/SharpCompress.csproj
+++ b/src/SharpCompress/SharpCompress.csproj
@@ -6,7 +6,7 @@
     <AssemblyVersion>0.20.0</AssemblyVersion>
     <FileVersion>0.20.0</FileVersion>
     <Authors>Adam Hathcock</Authors>
-    <TargetFrameworks Condition="'$(LibraryFrameworks)'==''">net45;net35;netstandard1.0;netstandard1.3;netstandard2.0</TargetFrameworks>
+    <TargetFrameworks Condition="'$(LibraryFrameworks)'==''">netstandard2.0</TargetFrameworks>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <AssemblyName>SharpCompress</AssemblyName>
diff --git a/src/SharpCompress/Utility.cs b/src/SharpCompress/Utility.cs
index 320a59c6..bca28a9d 100644
--- a/src/SharpCompress/Utility.cs
+++ b/src/SharpCompress/Utility.cs
@@ -427,10 +427,5 @@ namespace SharpCompress
             }
             return true;
         }
-
-        public static void CopyTo(this byte[] array, byte[] destination, int index)
-        {
-            Array.Copy(array, 0, destination, index, array.Length);
-        }
     }
 }
\ No newline at end of file