Does Weatherby recommend specific ammunition for each caliber to get the best accuracy?

These are not the only ammunitions you can use, but these are ammunitions regularly used during Weatherby factory accuracy tests.

CHAMBERING RECOMMENDED AMMUNITION
   
223 Remington Winchester 55gr Ballistic Silver Tip ( SBST223B )
  Federal 55gr Ballistic-Tip ( P223F )
  Barnes 55gr TSXFB ( 21520 )
   
22-250 Remington Barnes 50gr TSX ( 22008 )
  Winchester 55gr Ballistic Silver Tip ( SBST22250B )
  Federal 60gr Partition ( P22250G )
   
243 Winchester Barnes 80gr TTSX ( 21522 )
  Federal 100gr Game King BT-SP ( P243C )
  Winchester 95gr Ballistic Silver Tip ( SBST243A )
   
240 Weatherby Magnum Weatherby 72gr Hammer Custom ( M24072HCB )
  Weatherby 80gr Barnes TTSX ( B24080TTSX ) 
  Weatherby 100gr Interlock ( H240100IL )
   
257 Weatherby Magnum Weatherby 100gr TTSX ( B257100TTSX )
  Weatherby 92gr Hammer Custom ( M25792HCB )
  Weatherby 115gr Ballistic Tip ( N257115BST )
  Weatherby 110gr ELD-X ( H257110ELDX )
  Weatherby 100gr Scirocco ( F257100SCO )
   
25-06 Remington Barnes 100gr TTSX ( 21557 )
  Federal 120gr Soft Point ( F2506FS1 )
  Hornady 110gr ELD-X ( 8143 )
  Nosler 115gr Partition ( 60005 )
   
6.5 Creedmoor Nosler 140gr Accubond ( 60080 )
  Barnes 120gr TTSX BT ( BB65CRD1 )
  Federal 135gr Hybrid Hunter ( P65CRDBCH1 )
  Hornady 143gr ELD-X ( 81499 )
   
6.5 PRC Weatherby 156gr Elite Hunter ( R65PRC156EH )
  Weatherby 124gr Hammer Custom ( M65PRC124HCB )
  Weatherby 130gr Scirocco ( F65PRC130SCO )
   
6.5 Weatherby RPM Weatherby 124gr Hammer Custom ( M65RPM124HCB )
  Weatherby 130gr Scirocco ( F65RPM130SCO )
  Weatherby 127gr LRX ( B65RPM127LRX )
  Weatherby 140gr Interlock ( H65RPM140IL )
   
6.5-300 Weatherby Magnum Weatherby 129gr Hammer Custom ( M653129HCB )
  Weatherby 156gr Elite Hunter ( R653156EH )
  Weatherby 130gr Scirocco ( F653130SCO )
  Weatherby 127gr LRX ( B653127LRX )
   
270 Winchester Barnes 130gr TTSX BT ( BB270W1 )
  Nosler 130gr Ballistic Tip ( 40062 )
  Federal 140gr Hybrid Hunter ( P270BCH1 )
  Hornady Superformance 140gr SST ( 80563 )
   
270 Weatherby Magnum Weatherby 130gr TTSX ( B270130TTSX )
  Weatherby 130gr Interlock ( H270130IL )
   
7mm-08 Remington Hornady Superformance 139gr CX ( 805764 )
  Barnes 120gr TTSX BT ( BB7MM082 )
  Federal 140gr Trophy Bond ( P708TT2 )
  Nosler 140gr Accubond ( 60042 )
   
280 Ackley Improved Weatherby 139gr Hammer Custom ( M280A139HCB ) 
  Weatherby 150gr Scirocco ( F280A150SCO )
  Weatherby 150gr Tipped Game King( S280A150TGK )
   
7mm Remington Magnum Nosler 168gr Accubond Long Range ( 60108 )
  Barnes 140gr TTSX BT ( BB7MM1 )
  Hornady 162gr ELD-X ( 08636 )
  Federal 150gr Scirocco II ( P7RSS1 )
   
7mm PRC Weatherby 177gr Hammer Custom ( M7PRC177HCB )
  Weatherby 175gr Elite Hunter ( R7PRC175EH )
  Weatherby 150gr Scirocco ( F7PRC150SCO )
   
28 Nosler Weatherby 163gr Hammer Custom ( M28NS163HCB )
  Weatherby 150gr Scirocco ( F28NOS150SCO )
   
7mm Weatherby Magnum Weatherby 146gr Hammer Custom ( M7MM146HCB )
  Weatherby 140gr TTSX ( B7MM140TTSX )
  Weatherby 160gr Partition ( N7MM160PT )
  Weatherby 154gr Interlock ( H7MM154IL )
   
308 Winchester Barnes 150gr TTSX BT ( BB308W1 )
  Federal 168gr Hybrid Hunter ( P308BCH1 )
  Hornady 178gr ELD-X ( 80994 )
  Hornady 150gr CX ( 80944 )
  Nosler 165gr Accubond ( 60049 ) 
   
30-06 Springfield Nosler 165gr Accubond ( 60057 ) 
  Hornady 178gr ELD-X ( 81174 )
  Barnes 168gr TTSX BT ( BB30062 ) 
  Federal 180gr TSX ( P3006AE )
   
300 PRC Weatherby 195gr Hammer Custom ( M300P195HCB )
  Weatherby 180gr Scirocco ( F300P180SCO )
   
300 Winchester Magnum Federal 180gr Scirocco ( P300WSS1 )
  Barnes 180gr TTSX BT ( BB300WM3 )
  Nosler 190gr Accubond Long Range ( 60126 )
  Hornady 165gr CX ( 820264 )
   
300 Weatherby Magnum Weatherby 180gr TTSX ( B300180TTSX ) 
  Weatherby 170gr Hammer Custom ( M300170HCB )
  Weatherby 180gr Scirocco ( F300180SCO )
  Weatherby 195gr Hammer Custom ( M300195HCB )
  Weatherby 200gr ELD-X ( H300200ELDX )
  Weatherby 165gr Interlock ( H300180IL)
   
30-378 Weatherby Magnum Weatherby 195gr Hammer Custom ( M303195HCB )
  Weatherby 220 ELD-X ( H303220ELDX )
  Weatherby 180gr TTSX ( B303180TTSX ) 
  Weatherby 180gr Scirocco ( F303180SCO )
  Weatherby 180gr Interlock ( H303180IL )
   
338 Weatherby RPM Weatherby 185gr TTSX ( B338185TTSX ) 
  Weatherby 225gr TTSX ( B338225TTSX ) 
  Weatherby 225gr Interlock ( H338225IL )
   
340 Weatherby Magnum Weatherby 225gr TTSX ( B340225TTSX ) 
  Weatherby 250gr Interlock ( H340250IL )
  Weatherby 225gr Interlock ( H340225IL )
   
338 Lapua Magnum Hornady 270gr ELDX ( 82313 )
  Barnes 280gr LRX BT ( BB338LAP1 )
  Nosler 300gr Accubond ( 49323 )
   
338-378 Weatherby Magnum Weatherby 262gr Hammer Custom ( M333262HCB )
  Weatherby 225gr TTSX ( B333225TTSX )
  Weatherby 250gr Partition ( N333250PT )
   
375 H&H Magnum Nosler 300gr Partition ( 40606 )
  Hornady 300gr DGX Bonded ( 82334 )
   
378 Weatherby Magnum Weatherby 270gr TTSX ( B378270TTSX )
  Weatherby 300gr DGS ( H378300DGS )
   
416 Weatherby Magnum Weatherby 350gr TTSX ( B416350TTSX ) 
  Weatherby 400gr DGX ( H416400DGXB )
   
460 Weatherby Magnum Weatherby 450gr TSX ( B460450TSX )
  Weatherby 500gr DGX ( H460500DGXB )