Can't get scope base screw to fit in new rifle.

Tried installing a new scope mount on a rifle for someone this weekend and I cannot get the screws to start in a couple of the mounting holes, but they fit in others, tightly but they do get started so i believe they are the correct size/pitch, it's a dnz mount for an axis. Is a rough tap common with the cheaper rifles that they're rushing through? should i give it a try with a drop of oil and a little pressure? They include grade 8 screws so of it's just some burrs it should just cut some nice clean threads i would think.

I assume you do not have a 6-48 tap to run in there.

First, did you clean the threads well? All it takes is a little bit of grit or old thread lock/sealer for them to bind. Also make sure your new screws are clean.

Second, if clean and still not working. Do you have an extra screw around? If so, use a small file to make a notch in the end of the screw. Thread it in there. It will act like a cleanup 'tap'. BE CAREFUL. It is easy to cross thread and then you will have buggered up the rifle.

It's a really bizarro size or I would have a tap for it. It's a new rifle so there shouldn't be anything in the threads but I will give things a good cleaning and try again. I'm assuming it's just some burrs from running the tap fast.

Many models of the newer production guns are shot blasted for the matte look. You would be surprised how much metal shot gets where it is not supposed to go, and how it deforms sharp edges like on threads. Get a quality 6/48 tap and clean the holes out.

It always seems to be the hole closest to the barrel nut that got me. Once I got a 6/48 bottom tap all was well...have "fixed" at least 4 guns with it. Plus it does help to clean out and freshen up the other holes.

Yea it looks like I mite as well get one for the collection... at the very least i'll have it when I need it.

One of the holes on a new Axis I bought a couple of years ago was like that, sent the whole rifle back to them and they fixed it. When it came back they had installed some real cheap bases on it which I promptly removed and installed Talley one piece rings.