Blade Variance in a Pack

I recently switched to DE shaving from electric. My first DE shave was excellent. The wife complemented how smooth my face was and the scent of the soaps. The next couple of shave went just as well. I noticed hairs pulling more often after 3 shaves, so I decided to change the blade. I'm using a Shark blade on a Maggard DE razor (the razor is very comfortable to hold). This new blade cut ok but not as well as the first one. I noticed more nicks and irritation with this new blade from the same pack. I checked the razor and it was set up exactly the same as before. I tried shaving with this blade again today and there was more irritation and pulling hair. This blade is going into the trash too. Has anyone else experienced such variances from the same pack of blades?

*UPDATE: Tried the Durablade 7am sample pack. Took some more time but I noticed fewer pulled hairs. I still have some Gillette and Astra blades to try...