diff --git a/docs/source/pythonapi/examples/tally-arithmetic.ipynb b/docs/source/pythonapi/examples/tally-arithmetic.ipynb
index d1325e487..bbadd1ac4 100644
--- a/docs/source/pythonapi/examples/tally-arithmetic.ipynb
+++ b/docs/source/pythonapi/examples/tally-arithmetic.ipynb
@@ -418,15 +418,15 @@
     "\n",
     "# Instantiate flux Tally in moderator and fuel\n",
     "tally = openmc.Tally(name='flux')\n",
-    "tally.filters = [openmc.Filter(type='cell', bins=[fuel_cell.id, moderator_cell.id]),\n",
-    "                 energy_filter]\n",
+    "tally.filters = [openmc.Filter(type='cell', bins=[fuel_cell.id, moderator_cell.id])]\n",
+    "tally.filters.append(energy_filter)\n",
     "tally.scores = ['flux']\n",
     "tallies_file.add_tally(tally)\n",
     "\n",
     "# Instantiate reaction rate Tally in fuel\n",
     "tally = openmc.Tally(name='fuel rxn rates')\n",
-    "tally.filters = [openmc.Filter(type='cell', bins=[fuel_cell.id]),\n",
-    "                 energy_filter]\n",
+    "tally.filters = [openmc.Filter(type='cell', bins=[fuel_cell.id])]\n",
+    "tally.filters.append(energy_filter)\n",
     "tally.scores = ['nu-fission', 'scatter']\n",
     "tally.nuclides = [u238, u235]\n",
     "tallies_file.add_tally(tally)\n",
@@ -516,8 +516,8 @@
     "\n",
     "# Instantiate flux Tally in moderator and fuel\n",
     "tally = openmc.Tally(name='need-to-slice')\n",
-    "tally.filters = [openmc.Filter(type='cell', bins=[fuel_cell.id, moderator_cell.id]),\n",
-    "                 energy_filter]\n",
+    "tally.filters = [openmc.Filter(type='cell', bins=[fuel_cell.id, moderator_cell.id])]\n",
+    "tally.filters.append(energy_filter)\n",
     "tally.scores = ['nu-fission', 'scatter']\n",
     "tally.nuclides = [h1, u238]\n",
     "tallies_file.add_tally(tally)"
diff --git a/openmc/mgxs/mgxs.py b/openmc/mgxs/mgxs.py
index ad987d70f..68d34dce3 100644
--- a/openmc/mgxs/mgxs.py
+++ b/openmc/mgxs/mgxs.py
@@ -510,14 +510,14 @@ class MGXS(object):
         # Create each Tally needed to compute the multi group cross section
         for score, key, filters in zip(scores, keys, all_filters):
             self.tallies[key] = openmc.Tally(name=self.name)
-            self.tallies[key].scores.append(score)
+            self.tallies[key].scores = [score]
             self.tallies[key].estimator = estimator
-            self.tallies[key].filters.append(domain_filter)
+            self.tallies[key].filters = [domain_filter]
 
             # If a tally trigger was specified, add it to each tally
             if self.tally_trigger:
                 trigger_clone = copy.deepcopy(self.tally_trigger)
-                trigger_clone.scores.append(score)
+                trigger_clone.scores = [score]
                 self.tallies[key].triggers.append(trigger_clone)
 
             # Add all non-domain specific Filters (e.g., 'energy') to the Tally
diff --git a/openmc/tallies.py b/openmc/tallies.py
index 9d6ed4b7f..d56512155 100644
--- a/openmc/tallies.py
+++ b/openmc/tallies.py
@@ -449,9 +449,9 @@ class Tally(object):
 
         """
 
-        warnings.warn("Tally.add_trigger(...) has been deprecated and may be "
-                      "removed in a future version. Tally triggers should be "
-                      "defined using the triggers property directly.",
+        warnings.warn('Tally.add_trigger(...) has been deprecated and may be '
+                      'removed in a future version. Tally triggers should be '
+                      'defined using the triggers property directly.',
                       DeprecationWarning)
         self.triggers.append(trigger)
 
@@ -540,9 +540,9 @@ class Tally(object):
 
         """
 
-        warnings.warn("Tally.add_filter(...) has been deprecated and may be "
-                      "removed in a future version. Tally filters should be "
-                      "defined using the filters property directly.",
+        warnings.warn('Tally.add_filter(...) has been deprecated and may be '
+                      'removed in a future version. Tally filters should be '
+                      'defined using the filters property directly.',
                       DeprecationWarning)
         self.filters.append(new_filter)
 
@@ -565,9 +565,9 @@ class Tally(object):
 
         """
 
-        warnings.warn("Tally.add_nuclide(...) has been deprecated and may be "
-                      "removed in a future version. Tally nuclides should be "
-                      "defined using the nuclides property directly.",
+        warnings.warn('Tally.add_nuclide(...) has been deprecated and may be '
+                      'removed in a future version. Tally nuclides should be '
+                      'defined using the nuclides property directly.',
                       DeprecationWarning)
         self.nuclides.append(nuclide)
 
@@ -589,9 +589,9 @@ class Tally(object):
 
         """
 
-        warnings.warn("Tally.add_score(...) has been deprecated and may be "
-                      "removed in a future version. Tally scores should be "
-                      "defined using the scores property directly.",
+        warnings.warn('Tally.add_score(...) has been deprecated and may be '
+                      'removed in a future version. Tally scores should be '
+                      'defined using the scores property directly.',
                       DeprecationWarning)
         self.scores.append(score)
 
@@ -2324,9 +2324,9 @@ class Tally(object):
             new_tally.with_summary = self.with_summary
             new_tally.num_realization = self.num_realizations
 
-            new_tally.filters = self.filters
-            new_tally.nuclides = self.nuclides
-            new_tally.scores = self.scores
+            new_tally.filters = copy.deepcopy(self.filters)
+            new_tally.nuclides = copy.deepcopy(self.nuclides)
+            new_tally.scores = copy.deepcopy(self.scores)
 
             # If this tally operand is sparse, sparsify the new tally
             new_tally.sparse = self.sparse
@@ -2396,9 +2396,9 @@ class Tally(object):
             new_tally.with_summary = self.with_summary
             new_tally.num_realization = self.num_realizations
 
-            new_tally.filters = self.filters
-            new_tally.nuclides = self.nuclides
-            new_tally.scores = self.scores
+            new_tally.filters = copy.deepcopy(self.filters)
+            new_tally.nuclides = copy.deepcopy(self.nuclides)
+            new_tally.scores = copy.deepcopy(self.scores)
 
             # If this tally operand is sparse, sparsify the new tally
             new_tally.sparse = self.sparse
@@ -2468,9 +2468,9 @@ class Tally(object):
             new_tally.with_summary = self.with_summary
             new_tally.num_realization = self.num_realizations
 
-            new_tally.filters = self.filters
-            new_tally.nuclides = self.nuclides
-            new_tally.scores = self.scores
+            new_tally.filters = copy.deepcopy(self.filters)
+            new_tally.nuclides = copy.deepcopy(self.nuclides)
+            new_tally.scores = copy.deepcopy(self.scores)
 
             # If this tally operand is sparse, sparsify the new tally
             new_tally.sparse = self.sparse
@@ -2544,9 +2544,9 @@ class Tally(object):
             new_tally.with_summary = self.with_summary
             new_tally.num_realization = self.num_realizations
 
-            new_tally.filters = self.filters
-            new_tally.nuclides = self.nuclides
-            new_tally.scores = self.scores
+            new_tally.filters = copy.deepcopy(self.filters)
+            new_tally.nuclides = copy.deepcopy(self.nuclides)
+            new_tally.scores = copy.deepcopy(self.scores)
 
             # If original tally was sparse, sparsify the exponentiated tally
             new_tally.sparse = self.sparse