The original GS was a double chamber bullet like the Nosler Partition, and discontinued ummm loong time ago.
I've used Hot Cores since the '80's mostly in 270's - bought out a dealer in Lousiana one time at about $2-$3 a box and bought all he had in couple calibers or styles & made the already overloaded Suburban squat - and other under 3000 MV guns and always been satisfied with their On Game performance & decent but not stellar accuracy. IMO They are not a target bullet & don't make that claim.
I used to use 270gr Hot Cores in my 9.3x62 and the CZ could stack them in the same hole 5 at a time if I was doing my part...and a real thumper on game, with little or no meat damage.
Got some 120 gr 6.5's I used to put thru a Swede at max max MV's that were close to Sierra PH's acccuracy wise & a little tougher with nice consistent thru & thru's on WTails .
Found a source for some Fusion's that've been commrcially pulled from factory ammo, or sold in bulk as Blems occasionally and am looking forward to trying them when I burn up what I've got on the shelf.
Remember Aesops Fables outcome of the "Scorpion & and the Frog's" crossing the river when they get to other side
a LOT of Money doan't buy you ANY Class..old South Oak Cliff mantra
Those who fail to learn from History are doomed to repeat it...Santayana