I have a Porter Cable PCC790 battery powered 18 gauge brad nailer.

It will reliably shoot 1-1/2 nails. However, when I try to shoot 2" nails (its max nail length) is consistently fails (very occasionally firing one, but never two in a row).

The failure mode is:

  • Pull trigger
  • Hear bang/thud, but not as loud as on a successful firing
  • No nail has left the gun at all
  • Upon inspection the nail that should have been shot and the one adjacent to it have been moved ~1/16" in the direction they #1 was supposed to move, but no more. They are both still attached the the nail strip, and the whole strip can be easily removed from the loader. The nail has not separated, nor jammed anywhere
  • The firing pin has full receded

I'm guess that somehow the firing pin is on a slight angle, and coming in too low, so that for long nails it just catches nail #2 in addition to #1, whereas for shorter nails it misses #2 and hits #1 as intended. Does this seem likely? Any suggestions about how to repair it?

It's been like this since shortly after I bought it, but (shame on me) that's now more than 3 years ago, so no warranty any more.


  • 1
    are you using the correct brads?
    – jsotola
    Apr 8, 2022 at 5:44
  • 1
    Have you tried 1-3/4" nails? I would suggest finding a parts diagram for the nailer, stripping the firing mechanism down and checking for wear, play or misalignment of parts. Since you note that it's been this way from day one, it may have been misassembled at the factory. If it was, parts may have to be replaced since they may have worn improperly over the last 3 years of use.
    – FreeMan
    Apr 8, 2022 at 11:28
  • 1
    Is your gun rated for the longer brads? If it used to work a little light weight oil may help it on the slide and ram.
    – Ed Beal
    Apr 8, 2022 at 15:29
  • @FreeMan good question. I didnt have any 1-3/4 to hand, so i modified some 2" ones and 100% of the test strip fire perfectly. I will stick to 1-3/4", thanks.
    – tom
    Apr 11, 2022 at 21:26
  • @EdBeal, Yes, it's rated to 2", but per above, it seems that doesnt actually work
    – tom
    Apr 11, 2022 at 21:26

1 Answer 1


I have found this to be the case with almost all the 18 gauge brad nailers these days. Most of them claim a range of nail lengths up to 2" but very few can actually properly fire 2" brads consistently without misfires.

I have tried almost every brand from $200+ cadex and grex brand guns down to a $29 numax gun. Including hitachi, porter cable, bostich, etc.

The only gun I have now that will reliably shoot 2" brads is a senco finish pro MG18- and it is rated to shoot 5/8" to 2 1/8" brads.

I have no affiliation with any of these brands other than a long history of using them all.

The solution I have come to is using 1 3/4" brads instead- they seem to work fine in just about any of these guns.

  • Thanks, I shall use this solution too. As now noted in the question comments, I tested this and it worked.
    – tom
    Apr 11, 2022 at 21:28

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