Howa 1500 .308 missing a screw on the receiver(?)

[gsvault]

I was given a rifle by my father-in-law, probably over 20 years old. On the left side (shooter's left) of the receiver there is a hole about an inch from the barrel and directly below the scope mount that looks like it would fit a receiver screw, but there is not one in there. Anyone know if this hole has a purpose and whether it should be filled with a screw? Oil access? I've looked at the exploded diagram of a 1500 online, but can't find the hole or screw for that section. Thanks for your help.

[brickeyee]

Is the hole actually threaded?
There are often holes in receivers for venting in the event a case head ruptures.
These are often directed away fro were parts of your body might be when holding the rifle for a right handed shooter.
They are NOT normally threaded.

[gsvault]

I don't have the rifle with me right now, but to my knowledge it doesn't look threaded. Nor are there any signs that a screw was ever present in that part of the receiver. I've shot 20+ rounds with it and noticed it after I was cleaning it the other day.

[Harry Bonar]

Sir:
It's a gas vent hole if it's in the action ring - leave it alone.
Harry B.