I'm planning on taking my rifle to a gunsmith due to me messing up one of the screws for the scope base. I'm pretty sure I messed it up pretty bad when I tried using a screw extractor, so there's a chance the smith might recommend drilling and tapping to a #8 screw. If so, are there any good scope bases that uses a #8 screw for my rifle? Or would the gunsmith be able to just drill a regular #6 screw scope base to fit a #8 screw? Also would gunsmiths have extra #8 screws or should I bring some myself?

Gunsmith can take care of the base too.

Dakota bases are Model 70 pattern, but use larger screws, iirc. Not sure of size screws.

Any gunsmith ought to have an adequate supply of screws, or be able to make them.

That's reassuring since I already had a base on its way. I'll just wait for it to arrive and ask the gunsmith to attach it for me.

Is the screw stuck in the receiver? What brand base? I have extra 6-48 screws of different types and brands. PM me and I'll fix you up.

I've started using 5 min epoxy on my bases for the following reasons: 1. Won't loosen until you want it to. 2. Removes easily with heat excess of 165 f.  3. Won't rust between base and receiver. 4. Screws come out easy, locktite is a pain and requires more heat.

It's definitely not a loctite issue because I already tried heating and I see quite a bit of rust. The scope ring screws also had quite a bit of rust but some drops of hoppes 9 oil and some tapping and heating got them to loosen up but it looks like the rust is even worse in the base. This gun used to belong to my dad and now mine since he doesn't shoot it anymore and the current mounting system has been there for almost 30 years, that was why I was wanting to replace it since I saw quite a bit of rust. Probably should've went for a better penetrating oil but WD-40 was all I had on hand and thought it would be enough. I definitely had too much confidence in myself and should've just taken it to the gunsmith in the first place.

I'm not sure what brand the base is, but I think it might be redfield since the gun had a redfield scope on it and there's a R on the side of the base.

The screw is still in both the base and the receiver, it's just that the top half of it is drilled off thanks to me trying to use a screw extractor on it.
I'm fine on the screws because the new base I ordered will come with all the screws I need. Thanks for offering though.

The gun probably would've been fine if I just left the base there, but the rust was really bothering me and I wanted to clean it up.

If that Win 70 is pre-‘64, don’t tap to larger screw size.  That would alter its collector value.  

A good gunsmith can get it out, especially if the screw is still holding it to the base.  Heat will probably let him free it.  He can also put it in a good drill press, counter bore the base enough to make a new slot or drill through the center of the screw with a smaller diameter drill bit and get it to release that way and chase the original threads with a tap.