I guess I'm a bit confused, it's 30 lb braid but has a 12 lb mono diameter? Isn't 30 lb braid equivalent to 8 lb mono?

How is this line on a baitcaster? Is it stiff? Does it cast good like Power Pro 30 lb on a baitcast reel?

What I like is it's the only line that comes in a black/gray color as opposed to moss green. From what I can tell, I have 6 lb Fireline on a light spinning reel, the color holds better than Power Pro braid. I've not tried Fireline on a baitcast reel. Should I drop down to 20/8, if I am looking for an 8 lb diameter braided line in this brand?

I don't have much experience with Fireline, but unless they've added a new version, it's a fused line, not a braid, which is why the diameter is a little different. 

Actually, if you look at the listed diameter of the line in MM, it's .015, which is the same diameter listed as Trilene XL 17 pound mono. To get the same diameter as 8lb mono, you'd have to go to 10 pound Fireline. 

Ah, I forgot it's a fused line. That's interesting that the diameter is closer to 17 lb mono, way too thick. What is the 20 lb Fireline diameter in mono?

Looks like it's between 10 and 12 pound XL diameter. 

8 hours ago, ghost said:

I guess I'm a bit confused, it's 30 lb braid but has a 12 lb mono diameter? Isn't 30 lb braid equivalent to 8 lb mono?

How is this line on a baitcaster? Is it stiff? Does it cast good like Power Pro 30 lb on a baitcast reel?

What I like is it's the only line that comes in a black/gray color as opposed to moss green. From what I can tell, I have 6 lb Fireline on a light spinning reel, the color holds better than Power Pro braid. I've not tried Fireline on a baitcast reel. Should I drop down to 20/8, if I am looking for an 8 lb diameter braided line in this brand?

I'm curious. Why does the diameter comparable to mono matter so much to you?

If 30 lb Fireside has similar diameter to 17 lb mono, I won't be able to spool that much of that line on a bait cast reel. also Fireline is stiffer than Power Pro so that bigger diameter would not cast well with lures 1/4 Oz and up.

1 hour ago, ghost said:

If 30 lb Fireside has similar diameter to 17 lb mono, I won't be able to spool that much of that line on a bait cast reel. also Fireline is stiffer than Power Pro so that bigger diameter would not cast well with lures 1/4 Oz and up.

Fireline softens up pretty quickly after using it. Even then, I've never noticed any difference in casting distance between new "stiffer" line and line that has been broken in. Thinner line will always cast farther than thicker lines, which is one reason l have braid on all my reels. Capacity should be no problem.

Which Fireline product are you talking about?  There's at least four different types of line labeled "Fireline" in Berkley's catalog.

Original, it comes in a black/gray color and doesn't fade as quickly.

That isn't a braid, hence some of the confusion.  I wouldn't be trying to throw 1/4 oz. baits with the 30# size.  I had decent results with Crystal Fused in 14 and 20# size for that class of lure.  I eventually went to a regular 15-20# braided line, on a spinning rig for smaller baits, or just plain old 10# copoly on a casting rig.

Try out Gliss. I put it on my spinning reel and it cast very well, better than the braid that was on there. And it doesn't sound like it's "sawing" your eyelets either. 

I use a bunch of Original FireLine. I spool all of my spinning reels half full with 14 pound test Stren, then add 14 pound test Original FireLine fused line. The 14 pound test FireLine is the same size as 6 pound Stren mono,  009. To this I often attach a 4 foot leader made of P Line CXX in 10 pound test.

To answer your question 30 pound test FireLine is .015 which is about the same size as 15 pound Stren Clear Blue. I do not find FireLine stiff once it gets used.  I also never tried it on a baitcaster. My preferred line color in it is the bright green but the color you are talking about is smoke I believe.   20 pound test FireLine is the same size as 12 pound mono.

I would try it I think you will like it.  Just make sure you spool some mono on first so it has a nice smooth bed to wind on and the arbor knot will be tight and not slip. It also means that you save some money by needing to spool 1/2 as much.  One 300 yard spool will easily fill several reels.