A huge secret about pin nailers.
DO NOT BUY THE PIN NAILS FROM HARBOR FREIGHT.
Their pin nails are soft and tend to follow the grain. I was using the HF 1¼ inch pin nails in red oak. I had one turn a full 180° and come back out next to where it went in.
I use Porter Cable brand pin nails exclusively and I'm delighted with their performance.
Also while you're at HD, go to their bins of pneumatic couplers and buy a "Universal" coupler for the end of your hose. Put a few drops of AIR TOOL oil in the back end before you put it on the hose. The oil will help to keep from leaking for years. The Universal style of coupler will connect to Automotive or Industrial nipple tools. The Universal couplers seem to be more durable than either.
Also with the air tool oil in the gun, put the 4 or 5 drops of AIR TOOL oil in before connecting the air hose and after using a strip of pins. The oil tends to keep nail guns from jamming. HD carries Ingersoll Rand brand. Harbor Freight caries Sta-Lube brand which is about $1 less. But it is made / bottled in America.
[...]Aren't pins inclined to follow the grain, anyway?
For the record, I am still using the Harbor Freight pin nailer and their pin nails, too. I use the Harbor Freight tool oil in it as well. Admittedly, we have been using it mostly in cheap softwoods and cheap plywood, but occasionally in hardwoods, too.
I use it to hold pieces together to clamp them for glueing. Spouse uses it without glue for crafting projects.
We used it to pin 5/8 inch and 3/4 inch pin nails in my spouse's wood "crafting" project. The pin nails hold flat scroll sawn 1/4 inch plywood pieces to a slatted wood door, no glue. I estimate that we fired about 50 pin nails yesterday with zero problems. I also put 4 drops of tool oil in the nailer before I start using it.
Based on @NoThankyou
's wisdom and experience alone, I wish we had bought the Porter-Cable pin nails, but the ones from Harbor Freight seem to be working out okay for us.
P.S. My biggest problem with the nail gun is noticing when it needs a refill. More than once, I have been happily firing blanks, while the last nail is the only thing holding everything together.