Best nail gun / nails for 24x50mm softwood

[StuFirewood]

Hello all, my first post so apologies if this is in the wrong section.

I am looking for information about the best nailer to secure softwood batons together.

The batons will be 19mm or 25mm wide by 50mm deep. Treated softwood I believe.

I am looking for a nail gun that will have enough depth (75mm?) to hold the batons together but be thin enough that it doesn't splinter the wood?

Would a first fix dewalt be ok for this task (the finishings do not have to be decorative) or is there a finishing nailer that would stretch to a 70mm or 75mm depth?

Thanks!