That was easy! See link at Amazon.com for the staples in the size you want that used for your gun.

I got there by Googling your staple gun, and then looking at the staples sold for it.

Here is a link that might be useful: B & C Eagle 71/10 3/8-Inch by 22 Gauge Galvanized Staple

If you can find them, a stainless staple would be much better. I got the ones linked above and every single one that had to be removed broke easily. I dread what a project it will be if I ever have to reupholster the chairs I did with those galvanized staples. That said, I've not found anything better on Amazon yet. I was thinking of trying to find an upholstery supply place or something before I do my next project.

US38G
US12G
US58G
Which length do you want ?
Porter Cable site sends you Amazon for the 5/8

Here is a link that might be useful: http://www.amazon.com/exec/obidos/ASIN/B003XXAJU2/ref=nosim/13272130-20?s=merchant

FYI I know what staples I need off the the amazon site and manual what I'm asking is what off brand staples (hardware store) can be used. I already ordered staples but I was needing something for a weekend project. I was amazed no one in town sells upholstery staples.

If you have an ACE hardware nearby, call them. They carry various types for Porter Cable. The ones on the site are half price right now. Not sure if they are the right fit.

Sorry~Misunderstood.I've never had a problem interchanging the brand of staples.
Senco
Arrow
Stanley
Surebonder
Bostitch
Get the right size and guage~Read the back of the box.
Finding the size you want may be difficult.
Here is where size matters not manufacture.
Will these work ?

Here is a link that might be useful: Home Depot