Im not bashing but have a question. I've pretty much narrowed down the fact the my next bow will be a Black Ice or an Allegiance.(Maybe a Marquis).

I have read enough to understandhow they get an IBO speed. I not asking how they come with that number.

The question is- why do they advertise thier IBO speeds higher then what it says on the birth certs. I.. E... I looked at a Black Ice with is advertised around 310-317fps and only has 299 or 298on the birth cert. I also looked at the Allegiance and it is advertised(speed mod) around 327-335fps and the ones I looked at only had 311 on the birth cert. Same thing with the Marquis. 309 on birth cert and it advertised around 317+. I was just wondering why they advertise the bows higher then what they are, yet put the lower speed on the birth cert.

Do they use different tests for the advertised IBO and what is on the birth certs?