Upper tier jets are focused more towards missiles than guns, and Sweden commonly utilizes revolving or auto cannons, as opposed to the "miniguns" commonly seen on American aircraft
It's a trend with most aircraft that use single-barrel guns (or twin), like the Flankers which have 120 rounds each (iirc). Another part of the reason is smaller aircraft with larger rounds, Sweden commonly uses 27mm and 30mm, with most their Airframes being relatively small compared to their counterparts.
Also, the J35XS has like 150 rounds, iirc the A and D both have 200 split between 2 guns

@X99STRIKER Ya they all only have stealth belts too!

They’re all 30mm or 27mm

Or did they just decide if you can’t hit your target the first time you don’t deserve to fly a jet

Are they more powerful rounds?