Editorial Review
Two selectable trigger modes top the list of what we like about this roof nailer. With just a turn of a knob, you can increase your production and cut your work time using the bump-fire method, covering a huge area of roof in no time at all. When precision takes precedence over speed, just turn the knob back to sequential fire. If, for some reason, you want only the single fire, Porter-Cable will send you the mechanism for free.
Other features on this nailer are what you’d expect from Porter-Cable. The shingle guide adjusts quickly and easily and locks down securely for absolute consistency; the depth-of-drive adjustment is quick and easy to use, and it has detents at every quarter-turn of the knob. Non-skid pads on the housing help keep the tool from sliding down a steep pitch, and the rubber grip is smooth and comfortable. Though we didn’t experience any misfires or jams, you’d need a slender rod to nudge the driver blade up and a pair of needle nose pliers to pull out a jammed nail.
It’s got power, speed and precision for the professional roofer or the do-it-yourselfer up on the roof.--Kris Jensen-Van Heste
Amazon.com Product Description
Porter-Cable delivers professional results on job sites around the United States with the introduction of its new roofing nailer. This tool has a collated clipped head and nail length specifications to meet the roofing and nailing demands of any project. The new rounded body style offers increased comfort and the overall design has doubled the life of tool. The RN175A has a new rubber grip for increased ergonomics and aesthetics. The new roofing nailer has a selectable trigger that works in either restrictive or contact mode, which does not require any tools or other mechanism to switch from restrictive to contact mode. The RN175A uses 15 degree 3/4 to 1-3/4 inch wire collated roofing nails.
Technical Details
Uses 15-degree wire-collated ¾- to 1-3/4 inch roofing nails. Magazine capacity: 120. Firing mode: both single sequential and contact.
What's in the Box
RN175A coil nailer, 1/4" NPT Fitting, Oil, Wrenches & Manual.
Applications Roofing and siding.
Cached date: AWS Called=true
Customer Reviews
P.O.C.? 
2006-11-28
Why are so many people buying an RA175AR (reconditioned).
Is it because so many RN175A are bought and returned almost new? Now, why would that be? I thought I had done my homework and was getting a descent deal on a roofing nailer with the Porter Cable. Well, I saw that a large percent of the nails were not struck in the middle, but off center, which bent the head. A blow with my hammer would make the bent head cut the shingle. No hammering meant the head would be cocked up to maybe cut the shingle on top of it. My NR175A is now on it's way to becoming another nice looking RN175AR and I'm on my way to pick up a Bostitch RN46, or a DeWalt D51321, or a Hitachi NV45AB2, or a Makita AN451, or a Max CN450R, or a Senco 455XP, or maybe a Ridgid R175RNA.
Very good for the price - with some drawbacks 
2006-11-17
I had used a friend's Bostitch coil nailler several times in the past. It was finally time to buy one of my own. I have always been a fan of Porter-Cable tools. The fantastic price offered by Amazon on this refurb was too much to resist.
I unboxed my nailer to find it in almost new condition; one slight scuff mark. i was suprised to find it much smaller and lighter than the Bostitch I had used before. I had ordered a RN175AR but received a RN175A. I have no idea of the difference between these 2 models.
Part 1
A couple of weeks later I was ready to put it to the test.
Location - Luling, Louisiana - 25 miles from New Orleans
I had a circa 1960, 11 square roof that had been redecked with 1/2 plywood over 1 x 10 planks.
In keeping with the 30 year, architectural, shingle manufacturers specifications ( driven nails must extend through decking) I chose to use a 1 1/2 inch nail.
Compressor PSI set to 100 lbs.
Six nails into the job an obvious issue became apparent. Some of the nails had not been driven completely - a few whacks with a hammer and all was ship shape. Time to look for the depth adjustment. Whereas I had recieved a safety brochure but not an operation manual - I was left to clever out the depth adjustment mechanism. ( pretty obvious - as was the operation of switching between single nail and multiple nail settings.)
With the depth adjustment set to maximum I made another test. Same problem.
So I increased the compressor pressure to 125 lbs - Same problem.
Then 130 lbs ( the stated maximum for safe operation of the the tool.) - Same problem.
For every 10 nails attempted- 1 or 2 needed to be massaged with a hammer. Time consuming but assuredly better than hand nailing.
On that job a fellow worker was using his Rigid coil nailer. Outside of a couple of minor differences - the Porter Cable and Ridgid nailers appeared to be quite alike.
Was he having the same problem? Yes.
So I was able to conclude that this particular application exceeded the abilities of both of these nailers.
There was a section of roof that contained all new wood. In that area both guns worked flawlessly.
Part 2
Several weeks later a friend, who has far more roofing experience than I, asked to borrow the Porter- cable coil nailer. He had loaned his Bostitch RN145 out and could not wait for it to be returned.
Apprised of my experience - he thought of a possible solution. He needed to change the hose nipple at the rear of the gun from 1/4" to 3/8" to configure with his equipment. It seemed to make sense that this may solve the problem.
Unfortunately not.
Similarly, he was able to nail without problems into all new wood and only found difficulties when nailing into time hardened subdecking.
Conclusion
Putting our experiences together we have conjectured that the porter-cable because it is light and small is a great choice for new construction. However, the extra weight and size of the Bostitch (bigger piston with more mass) for about the same price (refurb), is the better choice for rennovations.
Caslo
This is the one. 
2006-09-27
I own a construction company and bought 2 of these "reconditioned" in the spring. 6 months and about 300 square of roofing later here is what I got:
NO jams
Maybe 1 in every 200 nails needs to be finished with a hammer
Survived multiple drops off roofs
My guys love how light it is compared to the Bostitch
Price is incredible, do not fear "reconditioned" tools- they came out of the box looking and working like new.
If you want a dependable nailer, that can handle even the biggest jobs,at a great price, then this is the one.
Love this nailer 2006-08-17
I got my mailer from Amazon at an incredibly low price, half that I was finding locally, so that might taint my review somewhat. Nice light weight, but still with some heft and robust built. Did a 10 square roof in two days using this nailer alone... can't imagine how sore I'd have been without it. Shot about 1/3 of a box of nails without a single jam... and only about 2-3 times that the firing mechanism missed a nail, probably because of a failure of the collating wires. Easy to load nails, multi fire setting works great without double firing. Highly recommended and holding up great. I love it.
RN175A-great little gun!!! 2006-07-04
I live in Brooklyn, MI and recently purchased a "reconditioned" Porter Cable RN175A roofing nailgun. It shipped quickly, looked brand-new and worked perfect. I needed it right away to roof a 16 square house and it did the job great! No jams-- I mean zero.Maybe 2 nails out of the whole roof needed to be hit down. However, I agree that a case would be nice.
instruction manuals not available on-line 
2007-10-11
Refurb Porter Cable roofing nailer model RN175A comes without a user guide.
Porter-Cable's web site support page link for "search for your manual" redirects to a site called servicenet.
Servicenet is under construction with limited functionality.
Isn't that sweet?
Servicenet's reference to "new user registration link above" can not be implemented because there is no link to new user registration.
A phone calls to Porter Cable's support line does offer the opportunity to leave a recorded message requesting a printed manual be mailed. But how long will it be before the Indonesian lady in the out-sourced fulfillment group deciphers my message, and the document arrives? 1 week? 1 month? Who knows?
The lack of a downloadable manual warrants a one star for this product.
Exceptional Roofing Nailer 2007-09-27
I purchased this nail gun based on my previous experience with the quality of Porter-Cable pneumatic tools. Aside from this one I own 4 other Porter-Cable nail guns, I have been very satisfied with all of them.
This nailer is no disappointment. In the time I have owned it I have used it for installing asphalt shingles, tar paper, aluminum drip end, vinyl siding, and vinyl trim pieces. It has performed very well in all instances. It has ample power to drive 1.75" nails flush while performing roofing applications.
The adjustable depth of drive also proves very useful while installing vinyl siding. Setting it to the minimum depth setting allows you to drive the nails into the nailing slots in siding while still leaving the 1/16" gap necessary to allow the siding to expand and contract under changes in temperature.
While using this nailer I have never experienced a jammed nail, it has always performed flawlessly. The only negative I can see in this nail gun is that it does not have marks on the nose to indicate exactly where the nail will be placed. This makes precise placement of the nail slightly difficult. I don't think this is enough of a negative point to reduce this nail gun from its "5 star" status because I very easily solved the problem by making marks of my own with a silver colored permanent marker.
Great roof nailer for the price 2007-07-07
Tool showed up the day before it was scheduled for delivery. Cool!
I've ordered refurbished Porter-Cable nail guns before and all have worked flawlessly. Only downside with this one is that it did not come with a case. The other two I've ordered (from different vendors on Amazon) both came with plastic cases. This one was wrapped in bubble wrap. It did have the small bottle of oil with it.
So far, no jams or problems, used on one roof.
Using to nail cement board siding 2007-06-19
Was lucky enought to get a new one (i.e. not reconditioned) on Amazon in early June which was being clearanced for just $160 (even had free shipping!). I'm using it on a small project to put cement board siding on my garage.
I've experienced some of the issues with having to finish some nails with hand-nailing, but I'm driving the max length 1-3/4" through a layer of cement. Seems to be less of an issue when well lubricated, but still occurs. Definately works better than the alternative of pre-drilling and hand-nailing. For the price, I'm ahead after this project.
Overall meets expectations.
A well made and functional tool 2007-06-19
IMPORTANT; PLEASE NOTE THAT THE ABOVE RATING SHOULD BE FIVE STARS INSTEAD OF ONE.
I purchased a refurbished version of this tool approximately ten months ago and have used it on several roofing jobs. In all cases, the unit performed very well and with no misfires. I did use a major brand of nails just to avoid any potential problem that might possibly result from a "unknown" product.
The Porter-Cable nailer is compact, easy to load and lightweight, making for comfortable extended periods of use. I do find myself needing to adjust the depth of drive rather frequently, but I am wondering if that is not necessitated by factors such as variations in the composition of the roof decking and even external temperature fluctuations which can alter the nailing resistance of the shingles. One other factor might just be the fact that being a rather careful worker, I probably checked the depth to which the nails were being driven more often.
Regarding that depth adjustment knob, I discovered an error in the manual which accompanied my tool. In the photograph which proports to show this feature, the trigger is mistakenly labeled as the adjustment knob. The instructions regarding the direction in which the wheeled knob is turned to either increase or decrease the depth to which the nail can be driven is also erroneously reversed.
However this was not a great problem as the various features on the tool are well marked and self explanatory, making for rather effortless use. (I especially appreciated the option of being able to easily select either the single sequential or contact actuation mode.) Additionaly, I have always found Porter=Cable/Delta to run an excellent customer hotline service which has always proven to be an added benefit in case one requires technical assistance.
