First, these days I am not much on Porter Cable tools. At this point their quality is questionable not only in design but in build as well. I wanted to set that issue aside lest the post be diverted to reminiscing about the good old days of PC.
I bought the PC RN175 nailer as a recon from CPO. The price is too much to resist for me as I use this particular gun as a light duty or back up gun. This gun turned out to be $69 plus delivery of $7.
This will be the second one of these I have had, and honestly can't tell how many nails the other unit had through it before it gave up. I am guessing about 75K, but that may be light. (For a roofing nailer, that is NOTHING.)
I use this nailer for plenty of other things beside roofing. It does well putting up foil backed board like Thermoply, nailing up metal flashings, and has nailed down a fair amount of 3/8" decking using the 1 3/4" nails. When I make site built trusses, it was used frequently to secure the gussets with about 15 nails a side on the gussets, again with the 1 3/4" nails. It has probably shot more nails than I think.
The gun still works, but the magazine if loose and worn, and it is almost worn through where it has been drug around by the hose. The ways are worn as is the feeding mechanism and it now has the irritating habit of catching a nail once and a while and crushing the head, requiring the drive head to be removed and the nail pulled out. So it is going to the "bin of last resort" to be used if my other guns are in the shop.
There are reviews out there that say this gun will jam frequently. A new one may or may not. We shoot as many as many as 25K per roofing gun a week (granted they aren't PC nailers) when we are in full gear, which is about normal. I have found the best way to keep a coil nailer like this one from jamming is to 1) buy quality nails, even if they are a couple of bucks more a box 2) keep the feed ways clean of debris 3) make sure the feed mechanism is clean and oiled with a light oil and 4) put some oil on the nose of the gun while holding it upside down so it will run into the driver guides. The biggest problem is that homeowners use compressors that are out of adjustment and let the pressure run down too low (this is especially true of big compressors) before they kick back on. Low pressure doesn't allow the gun to cycle with authority, and any bits of metal on the nails or the wire connectors that would be shredded off are bent, not broken. When we take the nose off any of our guns for a jamb, it is almost always because a nail was caught wrong and slammed to the side and the head broken off, or there is a piece of the wire connector stuck in the driver ways.
We run all of our nailers around 100psi. It is enough to ensure all my guns work properly, but lower pressure also means longer seal life.
Of course, YMMV with one of these. If you get any nailer, you should run a few clips/couple of coils through it to make sure it is working properly so it can be returned if needed.
If you get one of these, keep in mind there is one use that NO ONE uses it for, and that no one seems to know about. I use this nailer to install Hardie Plank! I found out by accident that a 1 3/4" roofing nail is approved by the Hardie folks. When I started installing Hardie about 25 years ago, the dedicated nailers were around $400 to $500. The job was a gable end, and certainly didn't merit buying a new gun. People were drilling holes with 1/8" bits and using chromed nails, some stalwarts were even using deck screws after drilling a pilot hole. I was already doing some roofing and had a clean gun to use to try it out. Works like a champ. Unlike my siding nailer, this gun can only shoot the nail flush, can't sink it, so NO spalling. The heads of the nails are thin enough that they disappear from piece to piece. Best of all, if my guys are out on a job without me, they can shoot up the siding and I don't have to worry about spall, in which case the siding will be loose or actually fall off. With this gun, no worries!
I have no doubt that if this gun wasn't used on a job site that it would still be in good shape. It is certainly a medium duty tool, but think of it as a utility gun, not just for roofing and I don't think you could help but get your money's worth out of it.
CPO has it on sale, ending today.
https://goo.gl/NYgRFS
Robert