What is this screw?

[Yeti]

This is on a Benelli M1 super 90. I bought it used. It had a scope mount on it. The mount had what appeared to be a hole drilled out by someone not at the factory to accommodate the screw. I am trying to mount a picatinny to it and this screw keeps it from seating properly. Wanted to ask you guys before removing it. The previous owner says maybe an “accuracy” screw for the slug barrel. But didn’t seem 100% sure and I have no idea and didn’t want to remove it if it needs to be there.

 

[Yeti]

@NiceOldDouble

 

[Average Joe]

What did the scope base look like underneath?

 

[Tim]

That definitely doesn’t belong there.

 

[Get Off My Lawn]

Is that on the receiver?
Mine looks like this. That’s a longer and an 18” defense barrel.

 

[Chdamn]

Those are speed holes.

 

[georgel]

If you pull the bolt, you'll likely see there's nothing on the other side. I think it was just to fill a hole or possible something to do with the previous scope mount.

 

[Yeti]

Is that on the receiver?
Mine looks like this. That’s a longer and an 18” defense barrel.
View attachment 554182View attachment 554180

Its on the top of the receiver. Mine has a slug barrel if that makes a difference.

 

[Get Off My Lawn]

Its on the top of the receiver. Mine has a slug barrel if that makes a difference.

Mine is a Stoeger import that’s about 25+ years old. It has a sight groove.

 

[Scsmith42]

the Screw head appears to stick up above the barrel. If so, I’m wondering if it’s purpose was to shim the back of the mount up?

 

[beamernc]

My M1S90 does not have that screw. I suspect when someone drilled and tapped it, they got that hole in the wrong location, so they plugged it with that screw.