IPSC Alex double sided mount with Romeo3 XL

[regor]

Posting this here because I couldn't find anything about this combo anywhere else. The IPSC Alex double sided mount for RTS2 lists the Romeo3 and Romeo3 Max as compatible optics, but not the Romeo3 XL. All share the same footprint so I figured I'd order a pair for my CMs and try it out, knowing that it would probably have a slight overhang at the front since the XL is a little longer than the Max. As you can see, the overhang is very minor, 2.3mm v. 1mm for the CZC mount I've been using. I don't foresee that causing any issues. The mount was a very tight fit for my primary gun; probably a good thing but unexpected. The one that I put on my backup (a slightly older Parrot with the larger front strap checkering) went on with much less pressure needed. Maybe just tolerance stacking or the newer frames are slightly thicker. 

 

Compared to the CZC mounts the Alex mount puts the optic about 1mm lower and 2mm further back. About half of that vertical offset comes from having a thinner surface for the optic to sit on, so the Alex mount has considerably less thread engagement for the optic mounting screws. The IPSC Alex mounts have steel threaded inserts and steel locating pins instead of threading directly into the aluminum surface and the threaded inserts provide  only 3-4 threads of contact, which is my only concern about this mount. The length of the optic mounting surface is slightly shorter on the Alex mount but with the rearward shift the back edge extends 2.5mm further back than the CZC mount; I doubt that's enough to impact ejection at all, but there's 1-2mm of excess material at the rear I could remove if needed. 

 

The weight of my CZC mount that came off this gun is 32g, the weight of the IPSC Alex replacement is 25g, so we're shaving a little bit of weight and shifting the weight slightly further back, though not enough to notice. The weight savings come from overall thinner material. The frame mounting arms are 3mm thick for the Alex mount and 5mm for the single sided CZC. At the optic mounting surface the Alex mount is 3.1mm thick vs the CZC which is tapered from back (3.6mm) to front (2.9mm). CZC mount is also much thicker at the edges, tapering from 4.8-4.1mm. 

 

The screws that came with the mounts are a little too short IMO, both for the optic and the frame. Both end slightly below flush with the last thread so I will probably get some extra M4 screws/bolts and cut them down to maximize thread engagement while still allowing proper slide clearance. I was going to have to do that with to frame screws anyways to mount the thumbrests I use, so not a huge deal.