Did I use too little priming sugar?

I brewed the brown porter recipe from Brewing Classic Styles about five weeks ago. I used Nottingham for the yeast. The OG was 1.055 and it finished around 1.016. I bottled after two weeks in the primary, and it’s now been in the bottle for a little more than three weeks. At three weeks, I put one bottle in the fridge for 48 hours, and when I tried it, there was very little carbonation and no head at all.

I have a question about the amount of priming sugar I used. The recipe says to carbonate to 1.5 to 2.0 volumes. The beer was at about 72 degrees when I primed. I used the nomograph in the book for determining priming sugar amounts, and I decided to shoot for 1.75 volumes. This told me I should around 2.3 ounces of corn sugar. Since I have no experience drinking any beers that have a lower carbonation level, I can’t tell whether I added too little priming sugar or if I simply have exactly what you would expect out of 1.75 volumes. Can anyone give me their opinion? Should I just give the beer a little more time, or is it probably about as carbed as it’s going to get?

That's a little more than 1/2 the priming sugar for what I would consider a 'normal' carbonation - I usually use about 4 ounces. I'd let it go for a little longer and see what happens, but I suspect your beer will have a modest carbonation.

Thanks for the reply.

Can anyone tell me what I should expect from a beer that is carbonated to around 1.75 volumes?

In case anyone is curious, this beer is great. I think it just needed another week. After I get one out of the fridge, I let it set out for 30-45 minutes before I open it since it's supposed to be served at 55 degrees. It has a nice head that diminished to a ring and then leaves some lacing. The carbonation is indeed moderate, but it seems to work great for this style.

Fantastic! Congrats on your beer!