Too much combined dextrose/brown cane sugar for priming?

So I just bottled my second batch of beer (first batch turned out awesome), this time I brewed the Honey Nut Brown Ale kit from Midwest supplies. I read a review on the Midwest website of the kit where a brewer added 1 cup of DME and 1/4 cup of brown sugar. He went on to say that he won a local competition, so I figured I would give that a try. Everything I read at first said priming with brown sugar shouldn't have any negative effects, but now I'm a little worried I added a little too much sugar and am concerned about bottle bombs. I bottled last night around 3:00 AM so it hasn't been too long. Any thoughts?

Also background on fermentation: 10 days in primary and 12 in secondary and final gravity reading was 1.013, taken right before bottling.

I think it will be fine. 1 cup of DME is equal to about 1/2 to 2/3 cup of corn sugar, and then another 1/4 cup of brown sugar will give you about the equivalent of roughly 1 cup of corn sugar altogether. I'm estimating quite a bit, but you're not going to be way overcarbed as long as you mixed well and let it condition at a good temperature.

In the future, use a calculator. Plenty of people get by on the old 3/4 cup of corn sugar rule of thumb, but I say if it's worth doing, it's worth doing with math.

Thanks for the help! I know where my assumptions on the review I read went wrong though, I'm an idiot and thought DME and the 5oz of Dextrose that came with the kit were the same thing, so in reality I primed 5oz of dextrose and about 1/4 cup of brown sugar o__O I think what I might do is keep an eye on them for tonight/tomorrow and put the bottles in the fridge and open/recap them to relieve some of the CO2 pressure, right now they're conditioning in a dark utility room in our basement at about 66 degrees

Oh, yeah, well that's a different story. 5oz of dextrose + 1.75oz brown sugar = almost 5 volumes CO2, and that's bottle bomb territory. That's just according to the math I get using the calculator I linked before (3.2 vol's from the dextrose and then another 1.7 from the brown sugar). Your plan should work in theory, just be careful and maybe put all of the bottles in a box or plastic tub or something to contain them in case something does go wrong. I've never had a bomb before, I don't know how violent they can be, but I'd hate for it to happen while you're handling them either. Keep us informed.

So it's been about 6 days since I bottled, and I have been keeping a close eye on the beers. I burped some of the beers, and they actually didn't seem to have too much carbonation in them so I decided to toss one that I hadn't degassed yet in the fridge and give it a try. They actually seem to be coming along fine, there was a little bit of carbonation built up but the beer was still mostly flat! I feel a little bit more at ease now but well see where the levels are at within the next week and a half or so. Thanks for the response, I definitely plan on weighing out sugar from now on and I'll keep an update on the final product.

Just an update, didn't have any bottle bombs and the beer carbonated right on schedule. I just knocked one back and it tastes amazing! I would almost say its under carbonated, maybe the yeast decided to utilize the simpler dextrose before the brown cane sugar? In any case me: 2 Brew mishaps: 0