How far from the muzzle does the choke stop the Match BBs? Or to ask differently, have you measured the tube to know where the choke is located and how long it is? You and your brother would know for sure but I would think measuring the choke might be easier if done with a gauge like what I use instead of the precision pins
Cvans brings up something to look into- a while back I measured the OD of the different BBs I had on hand at the time and Umarex looks to be a good alternative. But if it turns out Daisy zinc standard BBs shoot accurately, it's all good and will cost less for ammo to boot.
UMAREX
I mic'd 50, ~94% average right at 0.173” diameter.
DAISY PRECISION MAX zinc plated (ordinary Walmart)
I mic'd 50:
0.1710- 3
0.1715-1
0.1720-13
0.1725- 13
0.1730- 18
0.1735- 1
0.1740- 1
I'll send some along w/the other thing we were talking about