Too Bitter?

[CBMbrewer]

I'm going to be brewing an ipa next month. The grain bill will be based off of a loose cannon recipe found here https://www.homebrewtalk.com/f12/loose-cannon-brew-off-22278/
But I want to do my own hop profile with some of my favorites. I have tried the DFH 60 min approach of dividing all the hops into small amounts and hoping every few minutes throughout the whole boil and loved the final product.

I will be doing 10 gallons with a OG of 1.07 Here's what I was thinking

1 oz Simcoe, 1 oz Amarillo, 1 oz Columbus and .25 oz Chinook divided into 6 equal portions added at 60, 55, 50, 45, 40, 35
then
1 oz Simcoe, 1 oz Amarillo, 1 oz Columbus and 1 oz Centennial divided into 6 equal portions added at 30, 25, 20, 15, 10, 5 then something more at flame out, haven't decided.

Problem is, when I plug this into Brewer's Friend IBU calculator I get 108 IBU's I would like something more along the lines of 50 to 70.
The recipe for loose cannon lists their IBU as 149 and heavy seas lists the IBU as 45.
Am I missing something here? Would this hop schedule give ma a super bitter beer or is the calculated IBU going to be different then the actual?

 

[ncbrewer]

I use BrewTarget and also check with my own spreadsheet. They are in pretty good agreement, and my own perception agrees. You might try Brew Target and see what it shows. You could try one of the formulas as a comparison, too - I use Tinseth.

 

[Yooper]

Remember that any hops added to the boil before about 20 minutes from the end contribute primarily to bittering. You won't get hops flavor or aroma from a 60 minute addition, nor a 45 minute addition.

If you have those wonderful hops, I'd use them for flavor and aroma additions, instead of bittering!

I'd bitter with a neutral hop at 60 minutes, then add the hops at 15/10/5/0 and dryhopping. I'd get 30-40 IBUs with the 60 minute hops, and the rest of the IBUs from the last hops.

 

[hoppyhoppyhippo]

Loose cannon is a pretty love in IBUs like 56 according to Draft Mag

You can go higher than that of course, but if you added 1 ounce of Simcoe at 35 minutes, you're already almost half way there.

Having been to Heavy Seas most of their hop punch comes from them Hopbacking their beer (Randalizer) and then dry hopping it. So my suggestion would be if you wanted to get as much of a hop punch as possible divide your hops into thirds, split those up in your 60-30 hoppings, then split another 3rd into 15 minute and flameout, and then the rest for dryhopping.

 

[CBMbrewer]

From my experience with the "continues method" of hoping and what I have read and heard about dogfish head's approach is that extending the bittering addition over the first half of the boil as opposed to all at 60 minutes will give a less harsh bitter. This may be completely in my head but I do remember thoroughly enjoying the last ipa I did like this and love dfh's 60 min. Is this something anyone else has tried or should I really just stick to a tried and true method like 60, 15, 5,0 ?