Welcome to Just Answer. PORTER-CABLE PIN138 23-Gauge 1-3/8-Inch Pin Nailer. Porter-Cable BN200SB instruction manual and user guide 18 Gauge Pneumatic Brad Nailer BN200SB204460873 The plunger which strikes the nail does not retract all that way and interferes with the next nail. And I have to say it was pretty easy to do. Hey guys, My framing nail gun is about 12 years old. It sounds like an o-ring. I can remove the air supply and look down the barrel and see the plunger partly engaged and interfering with the next nail. It comes with instructions, all needed o-rings and lubricant. I recently had a similar problem with my Porter Cable roofing gun. Unlike the large nailiing guns PIN138 resolves the problem of splitting while fastening materials. Porter-Cable 18-Gauge Pneumatic Brad Nailer Kit Hardwood Floor Nail Gun Air Tool 5 out of 5 stars (49) 49 product ratings - Porter-Cable 18-Gauge Pneumatic Brad Nailer Kit Hardwood Floor Nail Gun Air Tool One of the smallest nailers in the industry that is best suited for clamping actions or light fastening is PORTER-CABLE PIN138 23-Gauge 1-3/8 Inches Pin Nailer. C. Porter Cable Pin Nailer Review 1. The gaskets failed on my Porter Cable pneumatic 18 gauge nail gun. I went on EBAY and found a complete Porter Cable o-ring overhaul kit for about $15.00. Sorry to hear about your problem.