Feedback on Holosun 509T mounting, to M&P C.O.R.E. interface

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  • jwamplerusa

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    I posted a question here regarding enclosed red dots.

    I have reached a decision, and so the next question I am posing is this:



    Thank you for any feedback provided.
     

    jwamplerusa

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    Update for anyone who runs across this thread in a search.

    The Holosun HE509T mounted to the C.O.R.E. interface using the RMR Type 1 M&P plastic plate, and the Holosun steel plate and screws.

    If I were to remove the optic I would trim the plastic plate down as it overhangs the optic cut and is a poke point when racking the slide.

    C&H Precision Weapons did get back to me and stated a direct mount plate is in their plan, but they have no ETA.

    A direct mount plate could easily lower the optic .120 inch, which would be beneficial.


    The 509T is easy to pick up, and the circle dot reticle is a winner. It doesn't have quite the tube effect of the ACRO, which I attribute to the ratio of length to window area.
     

    jwamplerusa

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    Update 2: Unfortunately the M&P C.O.R.E. interface does not play well with the Holosun 509T optic.

    With approximately 300 rounds through the pistol the mount screws failed. A picture is worth a thousand words, so I will shorten this write up with these.
    Slide.jpg

    S&W M&P CORE Type 1 plate.jpg

    Screw head cropped.jpg

    If you are going to go with this combination, beware of the interactions of the mounting interfaces. At this point I don't believe I would trust the C.O.R.E. interface plastic plates to hold anything.

    Next steps are to remove the screw remains from the slide (without screwing anything up), and then decide what to do next. One option may be C&H Precision Weapons SWMP-509T S&W M2.0™ C.O.R.E. Holosun 509T Plate & Slide Upgrade Combo, though that is a cost and modification I do not want to incur.

    Buyer beware guys...
     

    Dean C.

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    Great write up, I am curious however does the mounting system the M&P utilizes use recoil bosses?

    I ask due to the screws shearing.
     

    jwamplerusa

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    Great write up, I am curious however does the mounting system the M&P utilizes use recoil bosses?

    I ask due to the screws shearing.
    Dean,

    The first picture in post 3 shows the slide recoil bosses Smith & Wesson uses for the core system. The system also uses plastic adapter plates which fit over the bosses, the central raised circles, and rest against the rear abutment.

    With the tools and equipment I have at home I cannot make a confident failure assessment. The best I can do with a 10x magnifying glass and some study is that the screws primarily failed under tension. The picture does not show it well, but the fracture surface of the screw has the gray grain structure of a tension over stress fracture. There does however appear to be a faint line on both shank remains which may be an initiating crack on the recoil side.

    There are indications of shear on the 509T mounting plate and the plastic M&P adapter plate. I suspect however those may have occurred after screw failure. The second picture shows the plastic M&P type 1 RMR adapter plate with the front recoil lugs sheared off.

    Frankly, I'm more than a little annoyed with myself. When I learned the Smith & Wesson core system utilized plastic mounting plates I was very suspicious, but didn't listen to my better judgment. Mostly I became enamoured with a thought of a better trigger and the Pro Series moniker.

    I suspect this failure is a classic two entity interface issue where in the design of the Holosun adapter plate which has fairly sharp edged mounting holes, and the fitment between the slide plastic type 1 RMR adapter plate allowed the adapter plate with the weight of the optic to impinge on the screw shanks and initiate the failure.

    At this point I'll never know for sure. I just want to recover the slide without further damage, and get a system installed that will allow me to mount the 509T securely for the long term. (I love the optic, just wish there was a US made equivalent)

    If I had to do it over again I would likely purchase the cheaper 5-inch M&P and just have the slide milled. It probably would have cost slightly more, but I don't think I would have had to worry about the security of the optic on the pistol.

    I think this is what my father used to call the school of hard knocks. At least it was whenever the optic bounced off my forehead.
     

    Dean C.

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    Dean,

    The first picture in post 3 shows the slide recoil bosses Smith & Wesson uses for the core system. The system also uses plastic adapter plates which fit over the bosses, the central raised circles, and rest against the rear abutment.

    With the tools and equipment I have at home I cannot make a confident failure assessment. The best I can do with a 10x magnifying glass and some study is that the screws primarily failed under tension. The picture does not show it well, but the fracture surface of the screw has the gray grain structure of a tension over stress fracture. There does however appear to be a faint line on both shank remains which may be an initiating crack on the recoil side.

    There are indications of shear on the 509T mounting plate and the plastic M&P adapter plate. I suspect however those may have occurred after screw failure. The second picture shows the plastic M&P type 1 RMR adapter plate with the front recoil lugs sheared off.

    Frankly, I'm more than a little annoyed with myself. When I learned the Smith & Wesson core system utilized plastic mounting plates I was very suspicious, but didn't listen to my better judgment. Mostly I became enamoured with a thought of a better trigger and the Pro Series moniker.

    I suspect this failure is a classic two entity interface issue where in the design of the Holosun adapter plate which has fairly sharp edged mounting holes, and the fitment between the slide plastic type 1 RMR adapter plate allowed the adapter plate with the weight of the optic to impinge on the screw shanks and initiate the failure.

    At this point I'll never know for sure. I just want to recover the slide without further damage, and get a system installed that will allow me to mount the 509T securely for the long term. (I love the optic, just wish there was a US made equivalent)

    If I had to do it over again I would likely purchase the cheaper 5-inch M&P and just have the slide milled. It probably would have cost slightly more, but I don't think I would have had to worry about the security of the optic on the pistol.

    I think this is what my father used to call the school of hard knocks. At least it was whenever the optic bounced off my forehead.


    I should have been more specific , do the recoil bosses interact with the 509t or just the plastic adaptor plate. For reference below how the Walther PPQ plate system utilizes two sets of bosses one for the plate/pistol interface and one for the optic / plate interface.


    5s97ZQMh.jpg



    Qa8V25Zh.jpg


    And agreed , I have arrived at the same conclusion regarding mounting optics with just milling for the specific optic you want being the best option by far.
     

    jwamplerusa

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    I should have been more specific , do the recoil bosses interact with the 509t or just the plastic adaptor plate. For reference below how the Walther PPQ plate system utilizes two sets of bosses one for the plate/pistol interface and one for the optic / plate interface.


    5s97ZQMh.jpg



    Qa8V25Zh.jpg


    And agreed , I have arrived at the same conclusion regarding mounting optics with just milling for the specific optic you want being the best option by far.
    The recoil bosses on the slide only interact with the plastic plate. Though not entirely evident in the picture of the slide in post #3, the raised circles are not sharp edged cylinders and are poor recoil bosses. In reality, the most functional recoil bosses are the fore and aft abutments. Additionally, the plastic plates are not a tight fit between the fore and aft abutments of the optic cut.

    The 509T adapter plate only interacts with the plastic adapter plate recoil bosses for an RMR (the raised posts), and of course the screws. There have been additional developments, so check the next update below.
     
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    jwamplerusa

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    Update 3:

    I wrote to Smith & Wesson, and made multiple attempts to call with many minutes spent sitting on hold to no avail. Smith & Wesson has not responded to my FAX and I have been unsuccessful in getting a human on the phone. Frankly, I have had better customer service from Taurus.

    • Though I love my M&P pistols, I am REALLY disappointed in Smith & Wesson. While I am cognizant of their current work load and I expect their Customer Service organization is slammed, I would expect a response to a documented failure on one of their mid-grade products. The failure has also raised concern regarding their engineering practices. Assessment of the failure of the installation on their C.O.R.E. design is not flattering to their design and engineering choices.

    Based upon the best case from Smith & Wesson llikely being replacement of the sheared Type 1 C.O.R.E. plastic plate, which would not solve the underlying problem, I elected to send the slide assembly to C&H Precision Weapons for installation of their steel plate system.

    Between early December when I purchased the 509T and the failure of the C.O.R.E. mounting system, C&H announced their solution for installation of the 509T on a Smith & Wesson C.O.R.E. pistol (see post 2). The C&H SWMP-509T S&W M2.0™ C.O.R.E. Holosun 509T Plate & Slide Upgrade Combo revises the fastener location and type, and provides a fitted steel plate which will lower the 509T on the slide compared to use of the Smith & Wesson plastic plate + Holosun adapter and provide an all metal interface to the optic.

    Today I was contacted by Holosun regarding my e-mail to them January 2nd. The Holosun representative appeared to have a genuine interest in determining the reason for failure and indicated he had to update the management on the investigation of the reported failure by 1600 hours the 7th. (I have a Quality systems background, and what he was describing was a functioning continuous improvement and event investigation system) When I informed him the slide assembly had been sent to C&H, the Holosun representative indicated they had a relationship with C&H and he would investigate deferring part of the cost of the mod.

    I offered to provide the failed screw heads and plate, and the representative committed to finding out if Holosun's engineering staff wanted the parts and if they did he would send a label for their return.

    Overall I was impressed with Holosun's response. They took the initiative to contact me based upon the e-mail to their warranty e-mail address and the representative appeared to have a genuine interest in understanding the failure. Time will tell if there is adequate follow through. I did tell him if I was Holosun, I would caution against use of their adapter plate on a Smith & Wesson C.O.R.E. equipped pistol.

    Once I receive the slide assembly back I will post at least one more update with a picture of the C&H 509T plate installation.

    Based upon comments from C&H, Holosun, and my experience, my advice to any prospective purchasers of Smith & Wesson C.O.R.E. equipped pistols is to NOT utilize the supplied plastic plates. While they may be adequate for the optics directly identified in the M&P manual, any use with unlisted optics should be considered a probable failure point. For my own part, If I cannot get a steel plate for an optic I would install, the C.O.R.E. system would not be an option, I would just get a standard pistol's slide milled.
     

    jwamplerusa

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    Final update:

    I was never able to contact Smith & Wesson, nor did they reach out to me after receiving a FAX detailing the failure.

    Holosun was extremely responsive, and behaved in an exemplary manner with a high level of customer service. Holosun replaced the HE509T which impacted the floor, even though I did not ask for a replacement. Further, they defrayed the cost of the C&H Precision Weapon Systems 509T adapter plate installation.

    Note that I have dealt with at least three firearms related companies regarding product issues. Ruger and Holosun I would rank has having the best customer service and product support of those I have dealt with.

    Smith & Wesson has proven the worst of those I have dealt with. A truly disappointing performance for a company I held in high regard, especially for a failure related to one of their higher echelon products.

    The C&H slide plate and installation should be a sound fix. The plate is tightly fitted to the S&W recoil bosses, and is well matched to the slide contours. The end result is an installation which is more secure, lowers the 509T on the pistol slide, and should be far more durable.

    Outcome and recommendations:

    I can heartily recommend the Holosun HE509T-RD. My sample size of one survived a release from a slide, flew approximately 12 feet, impacted a Sheetrock wall and dropped to bare concrete from at least 6 feed high. The unit never missed a beat, and other than a barely discernible blemish on the aft right lower corner looked like it did when removed from the packaging. For me, the circle-dot reticle is a winner and I highly recommend it.

    I can recommend C&H Precision Weapon Systems. They were very accommodating, and produced what looks like an outstanding professional installation. Time will tell, but if the mount stays secure and stable it is worth every penny. The plate to slide fit appear tight and precise, the contours match the slide (something the S&W plastic plate did not), and as a bonus lowers the optic approximately .100 inch relative to the combination of the S&W plastic RMR plate and Holosun adapter plate. The HE509T also fits nicely within the recoil lug slot of the plate, with no perceptible fore and aft movement when set on the plate, and it moved the optic aft on the slide.

    My advice to any prospective purchasers of Smith & Wesson C.O.R.E. equipped pistols is to NOT utilize the supplied plastic plates. While they may be adequate for the optics directly identified in the M&P manual, any use with unlisted optics should be considered a probable failure point. Absolutely, do not trust the M&P C.O.R.E plastic mounting plate in conjunction with the Holosun HE509T adapter plate. That combination will require the procurement of a third party plate to directly mount the 509T to a C.O.R.E. pistol.

    For my own part, If I cannot get a steel plate for an optic I would install, the Smith & Wesson C.O.R.E. system would not be an option, I would just get a standard pistol's slide milled.
    PXL_20210126_160949512-1.jpg


    I hope this post will be of use to others. If you have questions, post them here or PM me. The final installation is shown below. (Now if I could just afford the ammo to really wring it out...)

    PXL_20210126_210153094-1.jpg
     

    Old_Guy

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    @jwamplerusa: Thank you for your very well written and informative posts. I joined the forum just so I can respond to you. I recently got the Performance Center version of the m&p core 2.0 with 5” barrel. I had the exact same problem you did. I mounted the 509t using the S&W plastic plate. It sheared the plastic post off the plate and snapped the screws, fortunately for me the 509 landed in the dirt a few feet away. Like you, I feel the plastic plates are inferior (the m&p 1.0 had steel plates) and would recommend not using them.

    I got this gun based on my experience with the S&W Performance Center 380 EZ I purchased for my wife. It has been a great gun. So I didn’t research (my bad, I know better than that) this particular gun before purchasing it. I couldn’t imagine S&W going to plastic plates. The 5” version like mine are known for accuracy issues due to dwell timing and lock up problems of the barrel design. As luck has it, mine is particularly inaccurate, and I would hate to see what a “regular” trigger feels like since mine is the Performance Center tuned version.

    I’m not posting just to bash S&W and in their defense the mounting plate that comes with the 509t is heavy. But I still cannot recommend using the plastic plates that come with the gun. Hopefully I’m not throwing good money after bad but I have installed an Apex trigger (much improved) and have one of their 5” barrels on back order. I just received a 508t that I’ve had on back order for months and will mount it using a C&H Precision plate. I may end up sending my slide to C&H precision to have the holes drilled and new 509t plate installed like you did but I’m going to wait to see if the Apex barrel really is the magic they say it is before spending even more money on the gun.

    Anyway, thanks again for your post and pictures.
     

    jwamplerusa

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    "I’m not posting just to bash S&W and in their defense the mounting plate that comes with the 509t is heavy. But I still cannot recommend using the plastic plates that come with the gun. Hopefully I’m not throwing good money after bad but I have installed an Apex trigger (much improved) and have one of their 5” barrels on back order. I just received a 508t that I’ve had on back order for months and will mount it using a C&H Precision plate. I may end up sending my slide to C&H precision to have the holes drilled and new 509t plate installed like you did but I’m going to wait to see if the Apex barrel really is the magic they say it is before spending even more money on the gun.

    Anyway, thanks again for your post and pictures.
    @Old_Guy, I'm not accurate enough to know if the barrel / pistol has accuracy issues. I too am somewhat disappointed in the trigger, for it being a Pro Series. I have a 4" compact with a few thousand rounds through it, and I like it's trigger better.

    If I had it to do over, I would have purchased a standard 5" and had it milled, or just gotten another compact and had it milled.

    I don't plan on putting anymore money in mine.

    I really do like the 509T, especially the circle dot reticle.

    Keep me up to date. I'm curious what kind of accuracy you achieve with the upgrades.
     

    Old_Guy

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    @jwamplerusa: I agree with you about the 509t, it's a great sight. I also really like the circle dot. Red dot sights really help these old eyes. I've had a RMR on my carry gun for a few years and shoot it just fine but I really like the circle dot. I like it so much I got 4 507K's to mount on other pistols, and a 530G to put on my Ruger PCC. I don't really know why I like the circle dot so much, it just feels comfortable. Although I'm not planning on replacing the RMR with one.

    I will definitely let you know how the new barrel turns out, but I don't know when that will happen since the barrel is on back order.
     

    Old_Guy

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    @Old_Guy, I'm not accurate enough to know if the barrel / pistol has accuracy issues. I too am somewhat disappointed in the trigger, for it being a Pro Series. I have a 4" compact with a few thousand rounds through it, and I like it's trigger better.

    If I had it to do over, I would have purchased a standard 5" and had it milled, or just gotten another compact and had it milled.

    I don't plan on putting anymore money in mine.

    I really do like the 509T, especially the circle dot reticle.

    Keep me up to date. I'm curious what kind of accuracy you achieve with the upgrades.
    @jwamplerusa: Update:

    Finally got the Apex barrel. I took my time fitting it per instructions from Apex. It really is magic, very accurate. Randy and Scott at Apex have figured it out. It’s hard to believe how much difference it makes. So much so that I had a couple of other shooters try it out, I had them shoot a 10 shot group with both barrels and they were also amazed at the difference. One of them shoots competition and he put all 10 rounds in a 2” group at 20 yards free hand.

    The next day I badgered my son in law to go out to the range and give it a try. He shoots a CZ Shadow 2 in competition. He also couldn’t believe the difference the Apex barrel made. He shot a 3” group from 20 yards free hand. Had it not been for one flyer he would have had a 1” 10 shot group. All of the groups were between 6 and 10 inches with the factory barrel. The Apex barrel is not ported like the factory barrel but none of us could tell any difference between the ported and non-ported barrel, maybe the porting would make a difference shooting fast but I haven’t tested that yet.

    So to date, I’ve had one very good experience and one very bad experience with S&W Performance Center guns and customer support. I know most companies have had problems with a gun they produced. The good companies will fix the issues and make it right for the customers. The accuracy problems with the 5” guns has been known for a long time, so for S&W not to address the problem with the 2.0 version guns means they simply don’t care. The Apex trigger and barrel have turned my lemon into a very nice gun but I think I’m done with S&W. Which makes me sad because I want to support American companies.
     

    Bigtanker

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    Friday I just brought home 4.25 P.C. CORE model. I haven't done much of anything with it except a few dry fires and backstraps swaps. I noticed the bag of plates and didn't pay much attention to them. They seem to have been metal but I can't be sure. I'll check when I get home.

    I'll be breaking the gun in with irons first and getting used to it. A dot will be later in the year most likely.

    Thanks for making this issue known.
     

    DadSmith

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    Thanks for the reports. I'm putting my next S&W buy on hold. If they treat customers like they did you I personally don't trust them.
    I just had an issue with my TX22 and Taurus has a new part on the way already. So Taurus has been good customer service wise so far.
     

    kaveman

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    I recently picked up an M2.0 Compact with a 509T direct milled to the slide. Seller stated that the work was done by Floyd's Custom Shop in Idaho.
    Definitely the way to do it. Holosun sits low enough to use the standard low irons and the sight isn't going anywhere.

    I've got several other M&P optics cuts mounting 507Cs with the S&W plastic plates, but don't trust them 100%. Stacking another adapter plate to mesh with a 509 would be a non-starter for me. From what I've read one of the problems is the quality of the Holosun provided screws,.....mine have all had quality screws from McMaster-Carr substituted. Found the discussion with screw specs through a search.

    As for the S&W supplied plates, well, adding another plate to adapt to a sight not intended for the gun kinda puts the onus on you. Stacking plates on a reciprocating slide has to be a bad idea and having one of those plates made from plastic can't help. Smith can't sell an optics ready slide unless it fits all the different footprints out there so they're going to have to be cheap, whether plastic in the case of Smith or sintered metal in the case of Glock MOS(which are just as bad from everything I've read). To sell a pistol with seven different high quality milled plates,.....six of which would never be needed or used,......would be economically unsound. There are only two answers,......throw the junk plates away and buy the one good quality plate you need,......or don't mess with optics ready in the first place and have the slide milled for the sight you intend to use(best practice by far!).

    My most recent purchase is an old M&P40C 1.0. Ack, but it had already been milled for a direct RMR so a 507C dropped right on. CHEAP, $325 off of GB, couldn't pass up the deal. From now on I'm buying non-optics cut guns and sending them out. These guys do cuts on M&Ps or Shields or others for $75 or $110 if you need a new rear sight slot cut. I've got a pair of LEO M1.0s I'll be sending to them.

     
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