Further thought
I am with KraigWy,
Since you did ask, I would really concentrate on selling your 629 first, as in almost any trade you make for a SD semi, you will come out on the short end of the stick to a substantial degree. Again you have not given the details of your gun, but if you got what the gun is worth you will have at least most of the funds to purchase your Semi, med frame revolver, and possibly enough to cover at least part of your shotgun.
And to KraigWy's other point, I agree wholeheartedly. The few guns I have sold or traded, even when I made out well, I still miss.
My philosiphy, is never trade or sell, just buy more
! Every time I have disregarded that way of thinking, I have regreted it, no matter how good of a deal I had.
.
There is no such thing as having enough guns, no matter how many guns one has, more is always better
! I may have a sickness, but if it is a disease, please don't cure me.
!!
Willy