Tongue-twisting rant for the letter 'R'

PETER POTTER BOATER BRUTE
FATHER RATHER GATHER GROUP
SHOWER HOUR POWER BREAD
NEWER SEWER FEWER DREAD

TRICKY TRIPPY TREMENDOUS TROT
RUMOUR RULER ROOSTER ROT
CRANE BRAIN GRAIN REFRAIN
TRUSTED CRUSTED BURSTED TRAIN

MUSTARD CUSTARD REGISTERED BASTARD
SHAKER QUAKER BAKER MASTERED
FETTER LETTER WETTER SWEATER
NURSE'S PURSE VERSES BETTER

INSTAGRAM AMSTERDAM
LORRY SORRY HORRIBLE PRAM
ARMS ALARM CHARMING WARM
WRIST PRIEST GREETING NORM

HIGHER WIRE CHOIRS ADMIRE
LIAR TYRES FIRE REQUIRE
WINKER PINKER TINKERBELL
JINGER FINGER LINGERS WELL

PEARS WEAR HARE'S HAIR
TEARS NEAR EARS FAIR