150 Sirrocco

I have not used them for long range, but what is long range to you? They may be fine.
I have used 168 gr. for longish range, and am currently using 180 gr VLD's for ranges from 800 to 1400 yards.
IME, a G1 BC of .488 has worked nicely for me as far as 750 yards. They start getting blown around a bit by then, but they have worked great, all in all.
What is the BC of your bullet?

 

I loaded them in my 7mag for years. They work great. It was one of the preferred long range bullets by John Burns prior to switching to the Bergers.

I found a website where Bryan Litz, at Berger, did testing on a lot of bullets and assigned a "corrected" BC. I don't remember if the Sciroccos were on that website. I suggest you email him to see if he did, and use that BC instead of what Swift puts out, unless they are the same, of course.

I used his corrected BC for the 150 nosler ballistic tip I'm using in my 280 and when I got to CO, my JBM chart couldn't have been more exact. I think Nosler said the BC was in the .48s and Litz said is was in the .45s

Be cautious though, JBM has a menu that is built in with given bullets and even though I had entered in the corrected BC, JBM changed it to published. I had to correct that and didn't notice it the first time.

The Scirocco is more finicky than the Nosler. It usually takes longer to work up a load. For 400-700 yards, I wouldn't hesitate to just use a Nosler ballistic tip.

 

IME is "in my experience." G1 is another BC number. There are 2, a G1 and G7 and they are different. Look here at Berger's website. They have both BCs listed with their products:

Hunting Bullets | Berger Bullets

 

You guys are fast!
I was in Utah for some prairie dog shooting and got left behind here.
There is nothing I can add here except to agree with Derek's comments. That bullet would work fine for the ranges you intend to use it.
If you are new to reloading, put on your seatbelt. Handloads will allow you to realize the full accuracy potential of your rifle, assuming your shooting skills are up to the task.

 

It is a bonded bullet, as you probably well know. I don't know why most LR bullets aren't bonded. SMK, AMax, VLD, JLK's - none of them are bonded. I suspect it is because of cost and not being necessary.

Only reason I mention this is that some people believe that the bonding is detrimental to LR accuracy. Not me personally. I don't have enough knowledge to have a valid opinion on the bullet

 

Nosler 150 gr. BT out of my 7MM WSM deliver me quite often 10 shot groups from 1000 yds. no larger than 8" and on occasion they've delivered a few 5" 10 shot groups. I don't think you'll have any gripes shooting this bullet. I don't sort or measure anything! I just shoot 'em!!

 

Shedhunt, there is a lot of knowledge to be found here on LRH. I would also suggest a few books that will rocket you past the basics.
Here is one I would start with;

Handloading for Competition
by Glen Zediker
Sinclair part #: 15-845
Midway part #: 875590

Another good one would be "The Book Of Rifle Accuracy" by benchrest hall of famer Tony Boyer.