

[#1]
None of our MOS compatible plate will work with LE only MOS models which should have the letter M removed from the MOS designation, since it's no longer modular, but milled for direct mounting of RMR (MOS5), ACRO (MOS7), 509T (MOS6(, DPP (MOS3).
We have no plans to turn MOS 3, 5, 6 and 7 into a regular, modular MOS with a center ridge (and no lugs or perpendicular locking bar slot), as a plate will raise the optic height by at least 0.10 (minimum thickness we can reliably mill steel plates out of solids), a 0.10 increase in RDS height will require a new set of backup sights. The first MOS 5 I saw had some issues, later ones seem to have tightened up but they too, have the gaps. Still better than 6061 plates with 0.020 tolerances though. |
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[#2]
Quoted: None of our MOS compatible plate will work with LE only MOS models which should have the letter M removed from the MOS designation, since it's no longer modular, but milled for direct mounting of RMR (MOS5), ACRO (MOS7), 509T (MOS6(, DPP (MOS3). We have no plans to turn MOS 3, 5, 6 and 7 into a regular, modular MOS with a center ridge (and no lugs or perpendicular locking bar slot), as a plate will raise the optic height by at least 0.10 (minimum thickness we can reliably mill steel plates out of solids), a 0.10 increase in RDS height will require a new set of backup sights. The first MOS 5 I saw had some issues, later ones seem to have tightened up but they too, have the gaps. Still better than 6061 plates with 0.020 tolerances though. View Quote Thank you for weighing in sir. |
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[#4]
I'm still trying to figure out why the MOS5 cut is so long. Is there any optic that uses the RMR post and screw spacing but that is longer?
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[#5]
Quoted: We ordered about 400 Glock 45, MOS 5 pistols. The cut is "sloppy" as pointed out. There is a gap between the front of the optic and the slide cut, the same at the rear. There are two index pins that go up from the slide and into the optic body. When combined with the two screws, that gives you four points of contact. So we're pretty sure they will not move if properly secured. We are still rolling these out. The optics were put on by Glock. I have had one that was so loose that I just took it off and remounted it. I have had a couple of more that were just a little loose. Probably because they were mounted in a hurry. You can only get the MOS 5 factory cut on department orders, so the fact that AIM has some to sell make them somewhat rare. At least to the general public. We wanted a direct factory cut. I don't know that we're happy with it, but it is mostly cosmetic . Honestly, I'm more satisfied with my personal MOS gun with the FCD plate then the factory MOS 5 cut. https://www.ar15.com/media/mediaFiles/668/IMG_1045-2883432.jpg https://www.ar15.com/media/mediaFiles/668/IMG_1060-2886485.jpg View Quote Your dept decided on the Holosun or is that a test unit? If you are definitely using Holosun was there internal testing before the decision? |
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[#6]
Quoted: Your dept decided on the Holosun or is that a test unit? If you are definitely using Holosun was there internal testing before the decision? View Quote I was not directly involved in the procurement process. But I can tell you that like most government agencies, most of what we do is driven by the amount of money in the budget. To my knowledge we did not test any other optics. I like the gun. I'm not sold on the optic. IMHO - If you get a 508T, set it so it is in auto mode, set it so it does not go to sleep, and then lock it. End users just keep pushing buttons and screw things up. |
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[#7]
We settled (not my choice) on auto adjust rmr. I bought my own rm06 so i can adjust it dim because of my astigmatism.
The autoadjust was selected by management and budget. When the rcr releases, i will buy one to test. |
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[#8]
Quoted: We settled (not my choice) on auto adjust rmr. I bought my own rm06 so i can adjust it dim because of my astigmatism. The autoadjust was selected by management and budget. When the rcr releases, i will buy one to test. View Quote Every set of eyes is different. I would try a 6 dot moa. I bought a rmr07 from a member here not knowing what to expect and holy cow, I could see the circle. The rmr06 and holosuns that I have do not look like that. And I notice also with the holosuns, that it is very dependent on a specific red dot. You may have one that looks good and then you buy one and it looks completely different. |
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[#9]
Some screws can do double duty as lugs and screws, RMR sight to plate screws are fully threaded and not of sufficient diameter to moonlight as recoil lugs. When pressed into service as lugs, it's not that they won't hold up, the 6-32x3/8 screws we use are rated for 160,000 PSI tensile strength, it's that when the fixed, immovable two front lugs can't keep the sight from moving in 1600G of recoil, the sight moving back and forth can loosen the screws, something even stronger screws with higher tensile strength can't fix, this results in loosened screws, and with weaker screws, they can shear.
It may take lots of rounds down range, or not many rounds before screws are loosened. For RDS with screws that go from the top down to the plate, whenever possible, we want to fix the sight in place or provide the sight something it can butt against in recoil, a big gap in front or rear, or both, doesn't provide that. |
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[#10]
Quoted: Some screws can do double duty as lugs and screws, RMR sight to plate screws are fully threaded and not of sufficient diameter to moonlight as recoil lugs. When pressed into service as lugs, it's not that they won't hold up, the 6-32x3/8 screws we use are rated for 160,000 PSI tensile strength, it's that when the fixed, immovable two front lugs can't keep the sight from moving in 1600G of recoil, the sight moving back and forth can loosen the screws, something even stronger screws with higher tensile strength can't fix, this results in loosened screws, and with weaker screws, they can shear. It may take lots of rounds down range, or not many rounds before screws are loosened. For RDS with screws that go from the top down to the plate, whenever possible, we want to fix the sight in place or provide the sight something it can butt against in recoil, a big gap in front or rear, or both, doesn't provide that. View Quote I was contemplating purchasing one cause I like the original finish but I don’t like the way they did the cut. I’m spoiled by battlewerx honestly. |
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[#11]
Glad I saw this thread. Was thinking of grabbing one of these. Didnt realize the optic cut was
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[#12]
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[#13]
Quoted: I was not directly involved in the procurement process. But I can tell you that like most government agencies, most of what we do is driven by the amount of money in the budget. View Quote This We went 509T but the cut is way tighter than these. Wonder why they left so much room in the RMR cut. |
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[#14]
I imagine with RMR HD and RCR with more sight mass above, it could exacerbate and amplify the problems, these issues already exist for plates that can't manage to hold the sights immobile.
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[#15]
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[#16]
RMR HD and RCR are compatible with Glock's OEM plate and RMR footprint, thus compatible with plates based on the OEM plate such as OPF-G, RMR. The raised bosses, threaded or unthreaded, will not be compatible with RCR, but RMR HD should work fine.
RCR uses capstan screws inserted from the sides, which renders these bosses unusable. RMR HD installs like RMR and SRO. |
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[#17]
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[#18]
Quoted: I'm still trying to figure out why the MOS5 cut is so long. Is there any optic that uses the RMR post and screw spacing but that is longer? View Quote If I had to guess it is because they wanted to as full a recoil lug as possible. If you do that you need around .130 clearance to get the .125 end mil cleanly through on the tool path for contouring the peg and a seperate contour path for the front of the pocket. Otherwise when you design for a tight optic fit on the front/rear kf the housing you wind up with the posts getting reduced to little 1/4 pegs like you see on every other cut slide. |
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[#19]
Quoted: It may take lots of rounds down range, or not many rounds before screws are loosened. For RDS with screws that go from the top down to the plate, whenever possible, we want to fix the sight in place or provide the sight something it can butt against in recoil, a big gap in front or rear, or both, doesn't provide that. View Quote From what I am starting to see in CAD/CAM is that the countersink/chamfer of the screws will also cam the sight into a position that the bearing surfaces of screw/sight dictate. Unless the sight interacts with another surface such as the recoil posts or closely cut slide tolerances to the housing. If the recoil posts are undersized it is possible for the sight to cant or slide in any number of directions as the screws are tightened down. Ideally the sight should damn near snap into place like a lego brick, which was one of the first things I ever machined while checking for tolerances and milling strategies. But tolerance stacking in production is likely to come into play, get a slide a few .001 undersized in the pegs and a sight a few .001 oversized on the pockets and as the screws tighten down the sight may only be in contact with one recoil lug. That one rrcoil lug being undersized will also only have a point of contact that is a small line/tangent contact point betwrrn peg and pocket. The screws are there to simply hold the sight down while the other points of contact take the load force. |
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[#20]
You have it correctly. RMR, SRO, RMR HD and RCR require pressure from both thumbs and a firm press before snapping into place on OPF-G, RMR plates.
For H sights, 507C and 407C usually do the same, but not 508T, it's a loose fit on all of our RMR plates (for Glock, SIG, HK, SW, and Staccato), thus we will not recommend using our plates with 508T, as the loose fit defeats our plate's design that holds the sight from moving by itself, and the screws only serve to apply clamping force, and don't serve as lugs. We don't support or recommend H sights, though 507c and 407c can and do work on our RMR plates. |
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[#21]
Quoted: You have it correctly. RMR, SRO, RMR HD and RCR require pressure from both thumbs and a firm press before snapping into place on OPF-G, RMR plates. For H sights, 507C and 407C usually do the same, but not 508T, it's a loose fit on all of our RMR plates (for Glock, SIG, HK, SW, and Staccato), thus we will not recommend using our plates with 508T, as the loose fit defeats our plate's design that holds the sight from moving by itself, and the screws only serve to apply clamping force, and don't serve as lugs. View Quote I have not run across a large enough sample size of sights to know how tight tolerances run on the posts. I am going to do a test of posts running in segments of .001 oversize up to around .003 oversized looking for that lego fit for an accurately sized post. But I am also likely to be cutting a precise pocket for mating surface at the front/reat of the sight. This is because I will have to do a relief of the recoil lugs when cutting with a .125 end mill. Playing with the notion of setting the 6-32 screws about .001 rearwards from where footprint calls them out. This would make the screw chamfers have a bias towards pushing the sight forward driving it into the recoil lugs. Would be similar to the camming vices of a Saunders Machine Works Mod-Vise. First cut is likely to be for a HoloSun 507C and it seems the outter dimensions of the sight body would have it loose in a few places to a perfect RMR cut. |
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[#22]
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[#23]
Quoted: Holosun and Trijicon can both provide prints with tolerances. This is for LED RMRs https://www.ar15.com/media/mediaFiles/781/LED_RMR_Drawing_png-2955868.JPG View Quote Optics trade EU seems to have done a nice job gathering all the info for various footprints as well. Always nice to have sight in hand to compare to the drawing. They are in metric so there is some conversion to do. /edit Just started taking some calipers to my 507C X2 to compare to the footprint I was working off of from Optics-Trade.eu. Once the 3in radius was set for the front of sight pocket I dinensioned the rear edge of the sight. All the measurements got dictated off the rear straight edge for ease of layout and later measurement. From metric my sketch overall length was 1.772 on drawing. With calipers on the sight is 1.774 from back of housing to the front of the curve. Hard to measure the recoil post pockets but I set my drawing to .153 on the posts and my measurement of the pockets on the sight is in the area of .153-.154. Measuring off the closest point of a recoil lug pocket to the rear of the housing I get right at 1.549-1.550 which matches my drawing. Measuring from rear most poi t of screw mounting holes I get .670 inches on my drawing with actual measurements as .674. If I am accurate in my measurements and drawing, with everything concentric, the tightening of the screws would draw the sight rearward which would pull the sight away from the lugs as I have them designed. This is all in bare aluminum as test cuts before trying some test cuts in steel. Then I will probably try opening things up .001-.002 and try some light coating of ceramicoat. Now to shut up and do some test cuts to see if what I think will happen actually will. |
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[#24]
Quoted: RMR HD and RCR are compatible with Glock's OEM plate and RMR footprint, thus compatible with plates based on the OEM plate such as OPF-G, RMR. The raised bosses, threaded or unthreaded, will not be compatible with RCR, but RMR HD should work fine. RCR uses capstan screws inserted from the sides, which renders these bosses unusable. RMR HD installs like RMR and SRO. View Quote @Duffy. Can I get clarification. RCR should be compatible with the MOS-5’s RMR footprint? Thanks |
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[#25]
Yep it'll work on MOS 5. Both RCR and RMR HD fit tight on OPF-G, RMR as we had hoped they would.
Just like an RMR, there will be a gap in front and rear of RCR and RMR HD in a MOS 5 sight pocket, Trijicon adheres to its established RMR footprint, including dimensions usually overlooked by some manufacturers: front radius, length, length between the lugs to the front edge / radius. Some sights uses the term footprint loosely, skilling on one dimension or another. I brought up couple of things with Trijicon: backup sights compatibility and holsters compatibility. Trijicon's description for both is unclear and vague, I wanted to warn them of potential blow back and complaints. RMR HD didn't fit the Safariland 6360 RDS and light bearing holster, and RCR literature states it's of the same deck height as RMR. The lowest RDS compatible RMR backup sights don't work with RCR or RMR HD, we compiled a list for easy reference. ![]() |
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[#27]
I just don’t see the point unless you’re a collector. The modular part of the MOS is lost and you’re boxing yourself into a single platform. I’ll stick to my 45 MOS with the P2 and FCD/TD plate and mods. Who knows what kind of optics we will have a year or two from now, at least with the standard MOS you can have a plate that allows easy adoption of new designs.
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[#28]
Quoted: found my pics from last year on the MOS-5 cut https://i.postimg.cc/sfQkb0cf/9B7EC3C2-24B6-4829-A455-78E614616286.jpg https://i.postimg.cc/j27BNL5n/4F8CF1E1-8DF5-4562-BA88-D5EDD70E63C9.jpg https://i.postimg.cc/YqQJCGZJ/B9F98AD0-B83D-4BFF-92B1-F1628F2F630E.jpg https://i.postimg.cc/59hhJq7B/71E6653F-6549-48FD-8F16-121ED095959C.jpg a little gappy, but I'm past 4k rounds with no issues on my duty gun. our practice ammo is win 9mm nato spec. here's my maple leaf cut on my 45. you can see it's a much tighter fit. https://i.postimg.cc/pLcrJ4Gz/IMG_5208.jpg the reason we went to the 45MOS-5 was because we couldn't get any 357sig ammo in and our chief forbade slide milling so we had dovetail plates on our 31s. So the 45MOS-5 was the answer for us. https://i.postimg.cc/cJ2nqLj3/2756D463-F7CC-4B09-86C9-065C48B2CBFC.jpg View Quote A dovetail mount isnt the wrong way to mount an optic...it is simply another way. Ive been using RCS Balors (T1 and RMR pattern) as well as Duek Defense RBUs on various guns for years with 0 issues. I even used a factory Trijicon dovetail mount for a while but the lack of irons caused me to ditch it for other options. |
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[#30]
The new RMR HD and RCR validate the modular design more than what we can say to convince folks. In 6 months or so, there will be another, and maybe more after that.
If you have a slide milled for ACRO and want to change to RCR, there is no easy path to it, and the reverse is also true. Similarly, if you have a slide milled with a footprint that differs from Glock's OEM plate (i.e. with bosses for the sight to plate screws, threaded or not), it precludes the installation of RCR. A milled slide doesn't mean it's better, I've seen milled RMR slides by lazy or incompetent shops that don't have recoil lugs. A competent steel plate will outperform a loosely cut and toleranced milled slide in reliability and durability, without giving up the modular aspect that is the M portion of MOS. |
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[#31]
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[#32]
Wow, that's worse than the ones I've seen, no lugs, front of the cut isn't radiused, and htey didn't bother to refinish the raw part
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[#34]
Quoted: yep, here's my $85 Maple Leaf RMR cut on my old duty gun which took a little over a week compared to a coworker who went somewhere local so he could wait for it and cost him $100. Guess which one was better? https://i.postimg.cc/0N9PvbFM/5C2A4630-78A7-4FB7-B1AE-1796EFB6B06E.jpg View Quote Anyone remember the name of that hack that used to be on this site? That looks like their work. Tooth an Nail or something like that. |
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[#35]
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[#36]
Quoted: you didn’t like the open striker spring channel? View Quote Extra feature free of charge! Oh yeah, that slide was refinished. The machine shop owner is business partner and childhood friend of Mike_P at Olympic Cerakote. A clear example of his best work. Y’all just don’t know what you’re looking at. |
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[#37]
HE wouldn't tell me who did it when I yelled at him about doing an unauthorized modification to a duty weapon. I made him buy that 31 back when we switched over to the 45MOS-5.
I'm guessing it was someplace around Akron, OH because he would be too cheap to drive too far and wait. |
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[#38]
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[#39]
Anyone wanna give me the answer on what are some reasonable back up irons, (black sights, lower 1/3 cowitness) when using an RMR on this thing?
I forgot how terrible factory Glock sights are. Lol. |
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[#40]
Quoted: Anyone wanna give me the answer on what are some reasonable back up irons, (black sights, lower 1/3 cowitness) when using an RMR on this thing? I forgot how terrible factory Glock sights are. Lol. View Quote How deep is the cut? I had battlewerx do my 19 slide and asked for sights that would match up the same as my mos setup. My mos are ameriglo gl429 and he installed ameriglo gl400 on my 19. |
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[#41]
Ameriglo xl height sights are barely visible in my rmr window.
They make a 2xl and 3xl height sights too |
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[#42]
GL-429 with a 0.315 tall front sight is the lowest you can go for blacked out sights. For sights with dots or tritium, it should be taller, at 0.35 or 0.365.
RCR, RMR HD, and SRO all need sight sets with at least 0.350, ideally 0.365 front sight. |
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[#43]
Our guns arrived from Glock with the sights installed on the slide. We have had a couple of cases where the optic was not torqued down properly. You can tell when the shooter's pattern opens up suddenly, and substantially. A few minutes with some Locktite and a torque wrench took care of it. So if you get guns with the sights installed at the factory, make sure you check tightness before you send them off to the range.
Also for large number of end users, here's my suggestion. Set the optic so it does not go to sleep. Put it in auto mode. Then lock it. Then tell the end users if they touch the buttons the sight will explode. Its the only way to ensure consistent functioning of the optic. ![]() I still prefer my personal RMR on the FCD plate, but the 509T is a good sight. Good glass, adequate brightness, and a titanium housing. |
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[#44]
Quoted: Also for large number of end users, here's my suggestion. Set the optic so it does not go to sleep. Put it in auto mode. Then lock it. Then tell the end users if they touch the buttons the sight will explode. Its the only way to ensure consistent functioning of the optic. ![]() View Quote This is the reason the chief went with the auto adjust rmr that never turns off. We have people that can't just leave something alone. When we installed Aimpoint PROs on all the rifles, I set them all at 6 and told everyone leave it at 6 so it's at a good level for nights and if you grab the rifle for anything you can adjust it if you need more. Never a call requiring rifle use and once a month when I take the long guns out, the PROs are set at max brightness. |
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