Any update from S&W on this? I had a screw shear today and I'm trying to decide where to go from here.Originally Posted by GJM
I received a CHPWS plate and was using the hardware from McMaster to install everything. The left screw felt "tight" and instead of halting like I should've I ended up with one sheared screw. I suspect an issue with the threading on that particular hole, the other side threads perfectly. It wasn't noticeable when I was using shorter screws to initially install my RDS.
My Safariland RDS a holster for the CORE is so tight, I can get the pistol out without a struggle. Will call Safariland CS.
I called S&W CS, was on hold less than a minute, and got a return shipping label from them — they said they would repair or replace the slide. Wanted the whole pistol since the slide is not serialized and said that was the only way they could track it in their system. By comparison, I was on hold thirty minutes with Sig CS, and never reached a person.
Likes pretty much everything in every caliber.
^@GJM same type of question with my new M2 compact. Which as you mentioned earlier in thread about the CORE models, also uses the 2.0 plastic base plates for RMR/SRO and other optic types.
Wondering if we could get any general guidance from S&W on avoiding the issue you ran into. So obviously some combo of the following:
* Run the metal CHPWS 2.0 plate which looks like it's still on backorder. Would this substantially help with the issue of the screws shearing off?
* Torque screws to certain inch-pounds.
* Like you said: rotate mounting screws as maintenance?
Interested to hear where you land on this, kinda' hoping to avoid that issue too.
I am not GJM and just putting in what I intend to do now. Good quality screws, 10 in lbs of torque on the screws, blue 243 loctite (it has a primer in it). Currently deciding about rotating screws out, maybe every 6 months or something along those lines to start.
^@GJM same type of question with my new M2 compact. Which as you mentioned earlier in thread about the CORE models, also uses the 2.0 plastic base plates for RMR/SRO and other optic types.
Wondering if we could get any general guidance from S&W on avoiding the issue you ran into. So obviously some combo of the following:
* Run the metal CHPWS 2.0 plate which looks like it's still on backorder. Would this substantially help with the issue of the screws shearing off?
* Torque screws to certain inch-pounds.
* Like you said: rotate mounting screws as maintenance?
Interested to hear where you land on this, kinda' hoping to avoid that issue too.
Yes, what he said.
Likes pretty much everything in every caliber.
Seems like a reasonable plan until more is known. Definitely makes you wonder if these will hold up under high round counts. It would be a hassle if it turns out the only long-term solution is to keep rotating your optic mount screws.
I think their are several USPSA participants out their with high round counts, no failures. Seems like not over torquing and loctite with proper cleaning before assembly is all we can hope for!
Seems like a reasonable plan until more is known. Definitely makes you wonder if these will hold up under high round counts. It would be a hassle if it turns out the only long-term solution is to keep rotating your optic mount screws.
Don’t guess.
There’s lots of engineering experience with screws and before one jumps into making recommendations they should probably understand what’s going on with the parts and the metal. If one is making torque recommendations and doesn’t understand ductility vs brittleness and tensile, compression, torsion, and shear stresses or how G-Force and vibration can affect those factors, and how threadlockers work (and why) then they should probably rethink that advice.
The C&H torque specs assume their plates with their components and their tolerances. If you’re not using their plates and you’re doing 10 in/lbs (say on an MOS plate) you may be disappointed.
We teach that one must first decide what components they need (sealing plate, aftermarket plate, aftermarket screws, etc). Then they need to prep the surfaces by degreasing. This includes threads in slides, plates, and the screws themselves. After that threadlocker should be applied. I hear people say they didn’t use it and it worked. Friction is cool but threadlocker is insurance and I’m about redundancy. I like loctite 248 and have used it on dozens of optics with good results. How it’s applied is important. Same goes for other threadlockers...especially Vibratite.
Then install the optic using the threadlocker applied screws. Once resistance is felt alternate bit by bit and use a torque driver to ensure proper torque is applied evenly. Torque applied should be the lowest specifications listed for any of the interacting components.
Indicator markings help identify a loose optic before shear stresses cause the screws to shear. Poor quality screws will perform poorly compared to better quality screws. Shear strength is not the same as tensile strength but depending on what engineering formula is used (which depends largely on the ductility of the metal) shear strength has a direct ratio to tensile strength (about 57%-60% or so). To me that means a crappy screw comes loose and may break really quick. A good screw gives more warning.
Coming loose sucks to begin with and when mating a metal optic to a metal slide the “torque”, as long as it’s enough to prevent all movement between components, is less important than the threadlocker since the torque values are pretty low compared to the forces applied. The goal isn’t to discover a loose screw early but to not have the screw come loose. With most decent screws, if they stay tight and prevent movement there will never be a problem.
Well said.
I received two new CORE 5 inch pistols today. On one of them, my preferred M/L grip piece in the box was so deformed it would not go on the pistol. On the other one, the overtravel stop was misssing, and the hole was not even drilled. Suggests that Smith is rushing to get product out the door.
Likes pretty much everything in every caliber.
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