Originally Posted by
FFWD
...I have LOTS of these to do.....
If you have lots make a jig that the part slides into aligning the dowel pin hole with a hole in a hardened guide bushing that is a clearance fit on the dowel and is just a bit shorter than the length of the dowel that protrudes once it is pushed home. Drop the dowel in the in the guide bushing and then push it home in a small arbor press.
The most likely reason you are getting dowels pulling out is because hammering them in can swage the hole slightly over size. If you could hammer perfectly in line with the dowel and if you can hold the dowel perfectly in line with the hole hammering might be okay. It is not possible to do either and hammering off line puts a sideways force on the dowel enlarging the hole.
An open mind is a virtue...so long as all the common sense has not leaked out.