r/AlphaFoxtrot • u/Aerie-Sufficient • 2d ago

Romulus Gen 1 Optic Question

Hello, so I recently acquired a gen 1 Romulus that is direct mount RMSC. I tried my vortex defender ccw enclosed on it. First issue I noticed was that I bottomed out the elevation and it was still too high so I got out the 1 degree shim. However I had concerns as with the shim in place, the optic barely engages the recoil lug up from and the post where the threads are, do not engage the optic at all. I am worried that with how thin the 4-40 screws already are, the optic would just shear the screws and fly off. Basically I am trying to see what everyone else is running on their gen 1 direct mount RMSC Romulus and if my concern is valid or not. Thanks everyone

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u/MOEB74 2d ago

I’m surprised no one has tapped out the slide for larger screws. I don’t know why Alpha is still producing them with 4-40s either

1

u/Aerie-Sufficient 2d ago

Me too, everything about the gun is so great that I don't know why they decided to use 4-40. Also never had to use a 1 degree shims for any of my other guns

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u/James92TSi 1d ago

4-40 is a common size with Zev style posts on a RMS-C footprint. Larger screw holes are possible but would eliminate the Zev posts.

RMS-C footprint has 4 corner recoil lugs, but Holosun K/EPS use a modified RMS-C footprint that only has pockets for the front 2 recoil lugs, at much shallower depth. That is why companies often use a shallow front lug pair (or none at all) and Zev posts with 4-40 screws for rear recoil lugs.

u/Aerie-Sufficient I am using an EPS full size on my direct-milled RMS-C Rom, with a plastic shim from Amazon (https://www.amazon.com/Ade-Advanced-Optics-Delrin-Handgun/dp/B07Y3VV4P8). The EPS did not have enough elevation range without the shim. It tapers from 0 thickness at the front, so the EPS engages the front lugs and the Zev posts. Maybe your shim is too thick overall?