To me, 884 grams is UNDERWEIGHT for a boar. With the exception of my new guy Simon, every single one of my boars has hit 1400 grams or higher. Leo is currently on the fence, just a shade under 1500 grams. He is a happy, active boy who runs and popcorns.
Punkin was the biggest, who tipped the scale once or twice at 1600 grams. Scooter at his heaviest was also just under 1500, but seemed to hold steady between 1400-1450. Both Sly and Pooper were also above 1400 grams.
Simon came to us at 967 grams, and he seems now to hover just below or just above 1000. Granted he is NOT comfortable yet in his new surroundings, and with all of the commotion and vet visit and whatnot he's going to take some time.
To give you a bit of perspective, both Scooter and Punkin weighed 890 grams at the 3 month old mark. When Punkin passed away at a weight of 1038 grams I considered that shockingly light for him. And Scooter passed away a couple of weeks ago at an even more shocking (to me) 830.
Every pig is different, just like people. If your boy is healthy, active and happy, his weight is likely just fine for him.