diff --git a/doc/HOWTO_MASSAGE_MA_GUN_DATA.md b/doc/HOWTO_MASSAGE_MA_GUN_DATA.md
new file mode 100644
index 0000000000000..b6bd51a3dc517
--- /dev/null
+++ b/doc/HOWTO_MASSAGE_MA_GUN_DATA.md
@@ -0,0 +1,52 @@
+These instructions are built around pretty standard linux command line tools, plus sqlite3 and moreutils.
+
+First, retrieve the .csv files from https://www.mass.gov/info-details/data-about-firearms-licensing-and-transactions
+You want both 'Download: Firearms Dealer Transactions <date range>' and 'Download: Personal Transfers and Registrations - <date range>'
+
+Translate the date fields to ISO-8601 like so `sed "s_\([^/,]*\)/\([^/,]*\)/\([^/,]*\),\(.*\)_20\3-\1-\2,\4_g" 01.01.23-12.31.23.csv`
+
+Remove frst line from all but the first sales csv like so
+tail -2 01.01.09-12.31.21.iso.date.csv | sponge 01.01.09-12.31.21.iso.date.csv
+tail -2 01.01.22-12.31.22.iso.date.csv | sponge 01.01.22-12.31.22.iso.date.csv
+tail -2 01.01.23-12.31.23.iso.date.csv | sponge 01.01.23-12.31.23.iso.date.csv
+
+Create a database, add a table like so:
+
+Import each file into the database like so:
+.mode csv
+.import personal_transactions.iso.date.csv personal_transactions
+.import 01.01.04-12.31.08.iso.date.csv sales
+.import 01.01.09-12.31.21.iso.date.csv sales
+.import 01.01.22-12.31.22.iso.date.csv sales
+.import 01.01.23-12.31.23.iso.date.csv sales
+
+Filter and rename the personal transactions columns while copying into a new table like so:
+CREATE TABLE gun_data AS SELECT "TRANSACTION DATE" as date, "BUYER STATE" as state, MAKE as make, MODEL as model, TYPE as type, "SERIAL NUMBER" as serial, "WEAPON SIZE" as ammo_type FROM personal_transactions;
+
+Filter and rename the sales columns while coping into the just created table like so:
+INSERT INTO gun_data SELECT "DATE OF TRANSACTION" as date, "BUYER STATE" as state, MAKE as make, MODEL as model, "WEAPON TYPE" as type, "SERIAL NUMBER" as serial, "WEAPON SIZE" as ammo_type FROM sales;
+
+Drop the intermediate tables.
+DROP TABLE sales;
+DROP TABLE personal_transactions;
+VACUUM;
+Possibly save and reload the database here?
+
+Run "script" to deduplicate the "not available" values for serial number.
+.read fix_serial_numbers.sql
+Run "script" to remove empty lines
+.read remove_empty_entroes.sql
+
+Deduplicate rows with matching serial fields, with latest date winning.
+CREATE INDEX gun_data_idx_deduplication_query ON gun_data(serial, date);
+DELETE FROM gun_data WHERE rowid IN (SELECT q1.rowid from gun_data q1 JOIN gun_data q2 on q1.serial = q2.serial WHERE q1.serial != "NONE" AND q1.date < q2.date);
+DROP INDEX IF EXISTS gun_data_idx_deduplication_query;
+
+Remove rows with a state field not equal to MA
+DELETE FROM gun_data WHERE state != "MA" AND state != "";
+
+Now you're ready to start fixing data entry errors.
+From this point on we don't use the date and state fields.
+
+Basically we have a big list of incorrectly spelled values for particular fields along with the correct spelling.
+Then we have a script that will spit out SQL statements to make these substitutions happen.
diff --git a/doc/firearm_stats/fix_serial_numbers.sql b/doc/firearm_stats/fix_serial_numbers.sql
new file mode 100644
index 0000000000000..94b07fcc75db3
--- /dev/null
+++ b/doc/firearm_stats/fix_serial_numbers.sql
@@ -0,0 +1,20 @@
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "NSN";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "N/A";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "NA";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "0";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "1";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "2";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "NO SERIAL NUMBER";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "UNKNOWN";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "NO SERIAL";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "NOT AVAILABLE";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "NO NUMBER";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "NONE FOUND";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "NONE VISIBLE";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "-";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "N.S.N";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "UNKNOW";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "NOT AVAIL";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "NVS";
+UPDATE gun_data SET serial = "NONE" WHERE serial LIKE "NO SERIAL #";
diff --git a/doc/firearm_stats/make_renames.in b/doc/firearm_stats/make_renames.in
new file mode 100644
index 0000000000000..41e9e03e1d707
--- /dev/null
+++ b/doc/firearm_stats/make_renames.in
@@ -0,0 +1,85 @@
+"ZASTAVA" "%ZASTAVA%"
+"YUGOSLAVIAN IMPORT" "%YUGO%"
+"YANKEE HILL MACHINE" "%YANKEE%HILL%"
+"YANKEE HILL MACHINE" "YHM"
+"WINDHAM WEAPONRY" "%WINDHAM%"
+"JAPANESE IMPORT" "%JAPANESE%"
+"JAPANESE IMPORT" "%ARISAKA%"
+"WINCHESTER" "%WINC%"
+"WILSON COMBAT" "%WILSON C%"
+"WEATHERBY" "%WEATHER%"
+"WALTHER" "%WALT%ER%"
+"SPRINGFIELD ARMORY" "%SPRINGFIELD%"
+"SPIKE'S TACTICAL" "%SPIKE%"
+"UNIVERSAL" "%UNIVERSAL%"
+"UBERTI" "%UBERTI"
+"TULA" "%TULA%"
+"TROY INDUSTRIES" "%TROY%"
+"TRISTAR" "%TRISTAR%"
+"TIKKA" "%TIKKA%"
+"THOMPSON CENTER" "%THOMPSON%"
+"THOMPSON CENTER" "%AUTO%ORDINANCE%"
+"TAURUS" "%TAURUS%"
+"TANFOGLIO" "%TANFOGLIO%"
+"SMITH & WESSON" "SW"
+"SMITH & WESSON" "S&W"
+"SMITH & WESSON" "SMITH%"
+"SMITH & WESSON" "%SMITH%WESSON%"
+"STOEGER" "%STOEGER%"
+"STACCATO" "%STI %" AND make not like "%FAUSTI%"
+"STACCATO" "%STACCATO%"
+"STEYR" "%STEYR"
+"STEVENS" "%STEVENS%"
+"STERLING ARMS" "STERLING"
+"STERLING ARMS" "%STERLING %"
+"STERLINGWORTH" "%STERLINGWORTH%"
+"STAG ARMS" "%STAG%"
+"SONS OF LIBERTY" "%SONS OF LIBERTY%"
+"SIG SAUER" "%SIG %"
+"SIG SAUER" "%SAUER%"
+"SHADOW SYSTEMS" "%SHADOW SYSTEM%"
+"SEECAMP" "%SEECAMP%"
+"SEARS" "%SEARS%"
+"SAVAGE ARMS" "%SAVAGE%"
+"RUGER" "%RUGER%"
+"ROSSI" "%ROSSI%"
+"ROMANIAN IMPORT" "%ROMANIAN%"
+"REMINGTON" "%REMINGTON%"
+"PARA" "%PARA%"
+"NORINCO" "%NORINCO%"
+"MOSSBERG" "%MOSSBERG%"
+"MOSIN NAGANT" "%MOSIN%"
+"MAUSER" "%MAUSER%"
+"MARLIN" "%MARLIN%"
+"MAGNUM RESEARCH" "%MAGNUM R%"
+"KIMBER" "%KIMBER%"
+"KELTEC" "%KEL%TEC%"
+"KAHR" "%KAHR%"
+"JC ARMS" "%JC%ARMS%"
+"IWI" "%IWI%"
+"IVER JOHNSON" "%IVER%J%"
+"ITHACA" "%ITHACA%"
+"HECKLER & KOCH" "HK%"
+"HECKLER & KOCH" "%KOCH%"
+"HECKLER & KOCH" "H_K"
+"HIGH STANDARD" "HIGH%ST%"
+"HENRY REPEATING ARMS" "%HENRY%"
+"HARRINGTON & RICHARDSON" "%HARRINGTON%"
+"HARRINGTON & RICHARDSON" "%RICHARDSON%"
+"HARRINGTON & RICHARDSON" "%H&R%"
+"GLOCK" "%GLOCK%"
+"LEFEVER" "LEFNER"
+"FN" "%FN%"
+"DPMS" "%DPMS%"
+"DANIEL DEFENCE" "%DANIEL D%"
+"DAN WESSON" "%DAN%WESSON%"
+"CZ" "CZ%USA"
+"COLT" "%COLT%"
+"CHARTER ARMS" "%CHARTER%"
+"CENTURY ARMS" "%CENTURY%"
+"CANIK" "%CANIK%"
+"BROWNING" "%BROWNING%"
+"BERETTA" "%BERETTA%"
+"BENELLI" "%BENELLI%"
+"ANDERSON" "%ANDERSON%"
+"AERO PRECISION" "%AERO P%"
diff --git a/doc/firearm_stats/make_updates.sql b/doc/firearm_stats/make_updates.sql
new file mode 100644
index 0000000000000..28148890e4b35
--- /dev/null
+++ b/doc/firearm_stats/make_updates.sql
@@ -0,0 +1,68 @@
+UPDATE GUN_DATA SET OG_MAKE = 'H&K' WHERE MAKE = 'HK';
+UPDATE GUN_DATA SET OG_MAKE = 'HECKLER & KOCH' WHERE MAKE = 'H&K';
+UPDATE GUN_DATA SET OG_MAKE = 'SPRINGFIELD ARMORY' WHERE MAKE = 'SPRINGFIELD';
+UPDATE GUN_DATA SET OG_MAKE = 'AERO PRECISION' WHERE MAKE = 'AERO';
+UPDATE GUN_DATA SET OG_MAKE = 'SMITH & WESSON' WHERE MAKE = 'SW';
+UPDATE GUN_DATA SET OG_MAKE = 'HARRINGTON & RICHARDSON' WHERE MAKE = 'H&R';
+UPDATE GUN_DATA SET OG_MAKE = 'HENRY REPEATING ARMS' WHERE MAKE = 'HENRY';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE = 'SAVAGE / ANSCHUTZ';
+UPDATE GUN_DATA SET OG_MAKE = 'STAG ARMS' WHERE MAKE = 'STAG';
+UPDATE GUN_DATA SET OG_MAKE = 'CZ' WHERE MAKE = 'CZ-USA';
+UPDATE GUN_DATA SET OG_MAKE = 'ANDERSON MANUFACTURING' WHERE MAKE = 'ANDERSON';
+UPDATE GUN_DATA SET OG_MAKE = 'ANDERSON MANUFACTURING' WHERE MAKE = 'ANDERSON MFG';
+UPDATE GUN_DATA SET OG_MAKE = 'ROCK ISLAND ARMORY' WHERE MAKE = 'ROCK ISLAND';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE = 'SAVAGE ARMS';
+UPDATE GUN_DATA SET OG_MAKE = 'FN' WHERE MAKE = 'FN AMERICA';
+UPDATE GUN_DATA SET OG_MAKE = 'WINDHAM WEAPONRY' WHERE MAKE = 'WINDHAM';
+UPDATE GUN_DATA SET OG_MAKE = 'WINDHAM WEAPONRY' WHERE MAKE = 'WINDHAM ARMS';
+UPDATE GUN_DATA SET OG_MAKE = 'WINDHAM WEAPONRY' WHERE MAKE = 'WINDHAM ARMAMENT';
+UPDATE GUN_DATA SET OG_MAKE = 'WINDHAM WEAPONRY' WHERE MAKE = 'WINDHAM WEAPONRY -USA';
+UPDATE GUN_DATA SET OG_MAKE = 'WINDHAM WEAPONRY' WHERE MAKE = 'WINDHAM WEAPONRY (LE SALE';
+UPDATE GUN_DATA SET OG_MAKE = 'WINDHAM WEAPONRY' WHERE MAKE = 'WINDHAM ARMS WEAPONRY';
+UPDATE GUN_DATA SET OG_MAKE = 'WINDHAM WEAPONRY' WHERE MAKE = 'WINDHAM ARMORY';
+UPDATE GUN_DATA SET OG_MAKE = 'SMITH & WESSON' WHERE MAKE LIKE '%SMITH&%';
+UPDATE GUN_DATA SET OG_MAKE = 'SMITH & WESSON' WHERE MAKE LIKE '%SMITH &%';
+UPDATE GUN_DATA SET OG_MAKE = 'SMITH & WESSON' WHERE MAKE LIKE '%SMITH W%';
+UPDATE GUN_DATA SET OG_MAKE = 'SMITH & WESSON' WHERE MAKE LIKE '%SMITH+%';
+UPDATE GUN_DATA SET OG_MAKE = 'SMITH & WESSON' WHERE MAKE LIKE '%SMITHA%';
+UPDATE GUN_DATA SET OG_MAKE = 'RUGER' WHERE MAKE LIKE '%RUGER%';
+UPDATE GUN_DATA SET OG_MAKE = 'SIG SAUER' WHERE MAKE LIKE '%SIG SAUER%';
+UPDATE GUN_DATA SET OG_MAKE = 'SIG SAUER' WHERE MAKE LIKE 'SIG ARMS';
+UPDATE GUN_DATA SET OG_MAKE = 'SIG SAUER' WHERE MAKE LIKE 'SIG';
+UPDATE GUN_DATA SET OG_MAKE = 'SIG SAUER' WHERE MAKE LIKE 'SIG SWISS';
+UPDATE GUN_DATA SET OG_MAKE = 'SIG SAUER' WHERE MAKE LIKE 'SAUER / SIG ARMS';
+UPDATE GUN_DATA SET OG_MAKE = 'GLOCK' WHERE MAKE LIKE '%GLOCK%';
+UPDATE GUN_DATA SET OG_MAKE = 'REMINGTON' WHERE MAKE LIKE '%REMINGTON%';
+UPDATE GUN_DATA SET OG_MAKE = 'MOSSBERG' WHERE MAKE LIKE '%MOSSBERG%';
+UPDATE GUN_DATA SET OG_MAKE = 'BERETTA' WHERE MAKE LIKE '%BERETTA%';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'SAVAGE ARMS CANADA';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'SAVAGE ARMS ONT CAN / SAVAGE ARM';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'SAVAGE ARMS / SAVAGE ARMS';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'SAVAGE ARMS CANADA, INC / SAVAGE';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'SAVAGE ARMS CORP';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'AVAGE ARMS ONT CAN';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'SAVAGE ARMS ONT CAN';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'SAVAGE ARMS INCORPORATED';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'SAVAGE ARMS INC. OF CANADA';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'SAVAGE ARMS CANADA / SAVAGE ARMS';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'SAVAGE ARMS,INC';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'SAVAGE ARMS USA';
+UPDATE GUN_DATA SET OG_MAKE = 'SAVAGE' WHERE MAKE LIKE 'SAVAGE ARMS INC / NONE';
+UPDATE GUN_DATA SET OG_MAKE = 'HENRY REPEATING ARMS' WHERE MAKE LIKE 'HENRY %';
+UPDATE GUN_DATA SET OG_MAKE = 'UBERTI' WHERE MAKE LIKE '%UBERTI%';
+UPDATE GUN_DATA SET OG_MAKE = 'SPIKES TACTICAL' WHERE MAKE LIKE '%SPIKE%TACTICAL%';
+UPDATE GUN_DATA SET OG_MAKE = 'ROCK ISLAND ARMORY' WHERE MAKE LIKE '%ROCK%IS%';
+UPDATE GUN_DATA SET OG_MAKE = 'ROCK RIVER ARMS' WHERE MAKE LIKE 'ROCK RIVER%';
+UPDATE GUN_DATA SET OG_MAKE = 'ZASTAVA' WHERE MAKE LIKE 'ZASTAVA%';
+UPDATE GUN_DATA SET OG_MAKE = 'FN' WHERE MAKE LIKE 'FN%';
+UPDATE GUN_DATA SET OG_MAKE = 'SPIKES TACTICAL' WHERE MAKE LIKE 'SPIKE%';
+UPDATE GUN_DATA SET OG_MAKE = 'SPRINGFIELD ARMORY' WHERE MAKE LIKE 'SPRINGFIELD%';
+UPDATE GUN_DATA SET OG_MAKE = 'CENTURY ARMS' WHERE MAKE LIKE 'CENTURY%';
+UPDATE GUN_DATA SET OG_MAKE = 'YANKEE HILL MACHINE' WHERE MAKE LIKE 'YANKEE HILL%';
+UPDATE GUN_DATA SET OG_MAKE = 'YANKEE HILL MACHINE' WHERE MAKE LIKE 'YHM%';
+UPDATE GUN_DATA SET OG_MAKE = 'YANKEE HILL MACHINE' WHERE MAKE LIKE 'YMH';
+UPDATE GUN_DATA SET OG_MAKE = 'YANKEE HILL MACHINE' WHERE MAKE LIKE 'YNAKEE HILL MACHINE CO YHM';
+UPDATE GUN_DATA SET OG_MAKE = 'WINDHAM WEAPONRY' WHERE MAKE LIKE 'WINDOM%';
+UPDATE GUN_DATA SET OG_MAKE = 'WEATHERBY' WHERE MAKE LIKE 'WEATHERBY%';
+UPDATE GUN_DATA SET OG_MAKE = 'WEATHERBY' WHERE MAKE LIKE 'WEATHBY';
+UPDATE GUN_DATA SET OG_MAKE = 'CESKA ZBROJOVKA' WHERE MAKE LIKE 'CESK%';
diff --git a/doc/firearm_stats/remove_empty_entries.sql b/doc/firearm_stats/remove_empty_entries.sql
new file mode 100644
index 0000000000000..88d6c41734ce4
--- /dev/null
+++ b/doc/firearm_stats/remove_empty_entries.sql
@@ -0,0 +1,2 @@
+DELETE from gun_data WHERE make = "" AND model = "";
+