Author Topic: Milling slide - SP01 Shadow  (Read 160 times)

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Offline mushkin

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Milling slide - SP01 Shadow
« on: October 08, 2019, 11:00:51 AM »
Hey,

So I’m going to mill my slide to fit a trijicon SRO on my Shadow.

Since I live in Sweden I cannot in any easy way send the slide of to one of the companies I’m reading about in this forum that frequently mill slides.

IM askin for help to determin how deep i Can cut the slot for red dot sight on a SP01 slide? Also, from the surface In this cut slot, how deep are the screw holes? How far forward is the slot beeing cut?

Can someone please help me with this or at least some of this measurements?

Thank you 😀

Offline earlan357

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Re: Milling slide - SP01 Shadow
« Reply #1 on: October 09, 2019, 09:39:23 AM »
This should be a fun one.  I did my SP-01 Tactical with a 2-axis CNC, but a good machinist can do it with a manual mill and a rotary table.

For starters, be thankful you have a Shadow which doesn't have a firing pin block or retainer pin.  The RMR/SRO mounting screws are just a bit too wide for a direct mount on the slide.  You'll need some kind of optic plate.  Fortunately, even with the plate, you can get the mounting surface down low enough that the hood on the SRO will almost touch the slide.  I thinned down a Trijicon RM62 gunsmith blank since it already has the recoil bosses.  I used four M3 screws to secure the plate to the slide.  The pocket was cut to exactly match the plate front to rear, so none of the shear forces were on the screws.  I could have used just two screws like most OEMs, but I had the room and wanted it to be bullet proof.  Minimum thread engagement for M3 is .120", so your plate pocket can't be lower than 0.120" above the deepest cut inside the slide.  You'll have to measure your slide to figure this out as I don't have a Shadow slide.  Another limiting factor is the firing pin channel.  Some places actually cut into the channel for a lower mount, but since the SRO hood limits depth, I would try to maintain at least 0.050" of steel above the firing pin channel.  As far as how far forward, that's going to depend on where you drill the mounting screws.  On the Shadow slides, they need to clear the extractor areas.  You'll also have to consider your rear iron sights.  If you keep the factory dovetail, you'll need to cut into the ejector pin.  If you choose not to have rear iron sights, you just need to stay in front of the firing pin retaining plate.  The plate will need to be at least 0.100" thick to get the minimum thread engagement for the 6-32 mounting screws. 

I recently sold my SP-01, but here are a few pics for reference.  I can't help with definitive measurements since my slide doesn't have the firing pin retainer and the depth and internal cuts are different, but you can probably cut the pocket somewhere around.25" deep.  Adding the plate, the optic would sit about .150" below the slide surface.  I used the Trijicon 1911 plate as a reference for mounting screw spacing. https://www.trijicon.com/images/general/CA428_RMR_Mount_Dimensions.pdf

My pocket was .090" in front of where the hammer touches the slide, but I don't have a firing pin retainer plate.  It leaves enough room to cut a Glock sight dovetail in front of the optic at the extractor pin if needed.  I cut my pocket 1.77" long with a 3" radius at the front, then cut back the flat rear section until my plate just barely pressed in with finger pressure.







RMR cut dimensions: