Thread: Base mounting bolts /machine screws m4x0. 7

After much searching i located some bases that will fit a Grunig round receiver, turns out the styer m has the same spacing so the Warne m810 fit, but unfortunately the mounting bolts are non standard, they seem to be m4x0. 7 and I am having trouble finding bolts with a small enough head to fit in the holes in the bases, short of lashing some standard m4 bolts anyone have another Solution?

If you have a week or two to wait I'd be very surprised if you couldn't find something here. Do a search for the type you want. M4 whatever ....

http://www.aliexpress.com/item/120pc...0-45b449c2e1ca

http://www.aliexpress.com/item/M4-Al...0-45b449c2e1ca

Originally Posted by Thedirge

After much searching i located some bases that will fit a Grunig round receiver, turns out the styer m has the same spacing so the Warne m810 fit, but unfortunately the mounting bolts are non standard, they seem to be m4x0. 7 and I am having trouble finding bolts with a small enough head to fit in the holes in the bases, short of lashing some standard m4 bolts anyone have another Solution?

@Thedirge Where are you located? 4mm screws are real easy to source, well they are where I live.
I have some Warne bases, I will check their screw head configuration and post my findings.

This is a Warne base, in this case one 1/2 of Rem 700 setup. Yours will be the same just different hole centres and different action diameter.
As you can see from the photo 4mm cap screws are "fatter" and taller in the cap than the supplied screws. I have used bases like these on a very old Barnard. I drilled to holes to 4mm and opened out the countersunk section with a suitable sized plug drill, and machined the shoulder of the screws to reduce the height. You can also use Low Head cap screws. Their head height is virtually the same as the supplied Warne screws. You still need to open up the countersink. Only issue with the Low Head screws is they have a reduced size hex key. Warne bases are steel so good and strong to work with. What you are wanting to achieve is easily achieveable.

m4x0.7 are the standard m4 metric pitch, so are really simple to get your hands on from any engineering shop, bearing supplier, repco etc.
If they are like the cap head bolts in the sako optilocks, then the heads will need to be turned down a little to fit in the base.

If you are Wellington based, I'm more than happy to turn down the screw heads to fit.

Thanks for the suggestions, finding standard m4 isn't an issue, I just thought I may have been missing a source of smaller cap headed versions, I dont really want to open up the countersink like Zimmer suggested as the hole spacing is only 10 mm which will open the countersink hole very close to the slot, so I guess I will have to machine down some heads of standard m4, any one have a local source of low cap head m4 in stainless?

Are torx head bolts smaller diameter? I know they can have a lowere head height than socket head cap screws