diff --git a/src/test/mempool_tests.cpp b/src/test/mempool_tests.cpp
--- a/src/test/mempool_tests.cpp
+++ b/src/test/mempool_tests.cpp
@@ -455,35 +455,6 @@
 
     pool.removeRecursive(pool.mapTx.find(tx9.GetId())->GetTx());
     pool.removeRecursive(pool.mapTx.find(tx8.GetId())->GetTx());
-    /* Now check the sort on the mining score index.
-     * Final order should be:
-     *
-     * tx7 (2M)
-     * tx2 (20k)
-     * tx4 (15000)
-     * tx1/tx5 (10000)
-     * tx3/6 (0)
-     * (Ties resolved by hash)
-     */
-    sortedOrder.clear();
-    sortedOrder.push_back(tx7.GetId().ToString());
-    sortedOrder.push_back(tx2.GetId().ToString());
-    sortedOrder.push_back(tx4.GetId().ToString());
-    if (tx1.GetId() < tx5.GetId()) {
-        sortedOrder.push_back(tx5.GetId().ToString());
-        sortedOrder.push_back(tx1.GetId().ToString());
-    } else {
-        sortedOrder.push_back(tx1.GetId().ToString());
-        sortedOrder.push_back(tx5.GetId().ToString());
-    }
-    if (tx3.GetId() < tx6.GetId()) {
-        sortedOrder.push_back(tx6.GetId().ToString());
-        sortedOrder.push_back(tx3.GetId().ToString());
-    } else {
-        sortedOrder.push_back(tx3.GetId().ToString());
-        sortedOrder.push_back(tx6.GetId().ToString());
-    }
-    CheckSort<mining_score>(pool, sortedOrder, "MempoolIndexingTest8");
 }
 
 BOOST_AUTO_TEST_CASE(MempoolAncestorIndexingTest) {
diff --git a/src/txmempool.h b/src/txmempool.h
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -323,7 +323,6 @@
 // Multi_index tag names
 struct descendant_score {};
 struct entry_time {};
-struct mining_score {};
 struct ancestor_score {};
 
 /**
@@ -398,8 +397,6 @@
  * - transaction hash
  * - feerate [we use max(feerate of tx, feerate of tx with all descendants)]
  * - time in mempool
- * - mining score (feerate modified by any fee deltas from
- * PrioritiseTransaction)
  *
  * Note: the term "descendant" refers to in-mempool transactions that depend on
  * this one, while "ancestor" refers to in-mempool transactions that a given
@@ -490,11 +487,6 @@
                                  boost::multi_index::tag<entry_time>,
                                  boost::multi_index::identity<CTxMemPoolEntry>,
                                  CompareTxMemPoolEntryByEntryTime>,
-                             // sorted by score (for mining prioritization)
-                             boost::multi_index::ordered_unique<
-                                 boost::multi_index::tag<mining_score>,
-                                 boost::multi_index::identity<CTxMemPoolEntry>,
-                                 CompareTxMemPoolEntryByScore>,
                              // sorted by fee rate with ancestors
                              boost::multi_index::ordered_non_unique<
                                  boost::multi_index::tag<ancestor_score>,
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -1037,10 +1037,10 @@
 
 size_t CTxMemPool::DynamicMemoryUsage() const {
     LOCK(cs);
-    // Estimate the overhead of mapTx to be 15 pointers + an allocation, as no
+    // Estimate the overhead of mapTx to be 12 pointers + an allocation, as no
     // exact formula for boost::multi_index_contained is implemented.
     return memusage::MallocUsage(sizeof(CTxMemPoolEntry) +
-                                 15 * sizeof(void *)) *
+                                 12 * sizeof(void *)) *
                mapTx.size() +
            memusage::DynamicUsage(mapNextTx) +
            memusage::DynamicUsage(mapDeltas) +