Forward Controls Design Aimpoint ACRO P1 Steiner MPS Adapter Plate Glock Gen 6 ORS Black OPF-G6 ACRO. For OPF-G6 ACRO sight sets with 0.385in height is minimum for ACRO P2 and provides lower 1/4 co-witness. Sight sets with 0.365in height is sufficient for Steiner's MPS. OPF-G6 ACRO has been tested with Aimpoint ACRO P2 and Steiner MPS those are the plates we trust and support. Forward Controls Design can't guarantee fit and function for Chinese made ACRO footprint sights. Whereas on the Gen5 MOS the M3 screws used for MOS plates are small and the thickness required required to accommodate the countersink of the M3 screw can be less than 0.1in. Gen 5 compatible OPF-G ACRO's top is nearly flush with the top of the slide. This isn't the case with Gen 6 ORS Glocks. Gen 6 ORS slides have two sets of screw holes (6-32 for RMR and M4 for DPP) both screws are larger with a much longer and larger countersink area to content with and the thickness of a base for the plate has to be thicker to accommodate it. OPF-G6 ACRO uses COTS made in specialized factories T20 M4 0.7 x 8mm plate-to-slide screws. These M4 screws are immensely strong (rated for 140000 PSI tensile strength) quality M4 screws are plenty and easy to source the use of COTS made in specialized factories screws makes practical and logistics sense. The top of OPF-G6 ACRO dovetail sits above the slide due to the plate needing to accommodate the countersink. While it's possible to lower the height by 0.02 to 0.03 it'd either involve custom fasteners (doable but limits an agency's or a deployed unit's ability to easily source them) or make the ACRO dovetail shorter and out of Aimpoint's ACRO TDP specs which isn't an option to us at all we've seen the predictable results of out of spec ACRO plates either move on the plate along the bore or launch the sights towards the user's face. An out of spec ACRO footprint can also fail to seat Steiner MPS properly. Forward Controls Design ACRO plates have always supported both Aimpoint P1/P2 as well as Steiner's MPS making the ACRO footprint out of spec which results in poor sight retention in exchange for a lowered installed RDS height by 0.02 or 0.03 is a misplaced priority and terrible compromise we will never make. Gen 6 ORS pocket has a spindle shaped cavity/depression designed to prevent the plates from rotating shifting longitudinally and laterally. There is also a small 45 degrees rear locking tab to keep the rear of the plate down. All OPF-G6 plates have a bottom contoured to fit and fill out the spindle cavity they also have a small relief in the rear to make use and engage the ORS pocket's rear locking tab. When installing OPF-G6 plates the rear of the plate must be inserted into the rear ORS pocket at an angle the front of the plate then can be rotated down into the pocket the same way factory polymer inserts are installed. Glock Gen 6 ORS provides means to secure the plate in the ORS slide OPF-G6 plates take full advantage of the tools Glock provides. OPF-G6 ACRO uses the entire ORS pocket to index and keep the plate from moving along the bore laterally and rotating as seen in the picture below. Significant lightening cuts are on the bottom of the OPF-G6 ACRO plate. The tool marks visible inside the lightening cut are not visible when the plate is installed on the slide and inconsequential they measure in microns. We mill our plates out of solids we do our best to avoid tool marks but some will still be visible. An Aimpoint P2 will require backup sights with a front sight of at least 0.365in a Steiner MPS will only need sights with a front sight height of 0.350in with OPF-G6 ACRO. These backup sights are already in wide use with Gen 5 MOS ACRO and RMR HD RCR SRO equipped weapons. Depending on the ORS slide tolerances a miniscule gap between 0.001in to 0.002 can appear on the front bottom of the plate this can exist on any and all Gen 6 plates. The gap is cosmetic and impossible to eliminate without causing some plates to sit at a slight angle on some slides. Elimination of the gap (not possible with all slides) doesn't make the plate more reliable but it will change the elevation on slides where the depth in that area is shallower. All OPF-G6 plates are milled in 17-4 stainless steel. 17-4 stainless is an option we've made available on many of our Gen 5 MOS plates for MIL and LE customers it's standard on FCD Gen 6 ORS compatible plates. We don't believe aluminum is a suitable material for anything that can experience up to 1800G in recoil especially for sights like P2 and MSP that use a cross bolt. A 1.2oz RMR weighs 112.5lb in 1500G of recoil. Will 7075 hold up and to a lesser degree will the softer 6061 hold up? We're not taking chances with aluminum. 17-4 SS is more expensive to source and time consuming to machine our way has always been about the best we can muster not the cheapest. Regarding construction tolerances and material Forward Controls Design position is rather cut and dry and consistent: no