Direct milled slide mounted optic vs plate system slide mounted optic, wear and tear?

[hurley326]

 

In full disclosure this is related to slide mounted optics opposed to a true open pistol. I didn’t find a carry optic topic so figured could go here.

 

Currently debating a statement a fellow shooter made, “several instructors report that they see most slide mounted optic failures, on steel framed guns with a direct milled optic compared to plate mounted systems on polymer guns (think MOS). Because of this they believe that the plate mounted systems last longer due to the plate providing a buffer mitigating “harmonics” aspect of recoil and thus increased wear on the optic.“

 

I disagree and think it’s a very weak theory implying that correlation equals causation. I believe it’s more likely that there are higher failure rates on direct milled slides due to those guns seeing significantly higher round counts than plated systems like on a Glock MOS. Someone who pays to have their slide milled likely shoots more than the casual shooter who picks up a OEM plate mounted option. Not always but i think it’s fairly accurate. I’m not an engineer so I am not denying that a plate could provide some buffer from “harmonics” as they said but I doubt that aspect contributes to the wear and tear anywhere near the level of reciprocating force that is applied in both options. Also on the claim they made on steel frame vs polymer, I would think a steel framed gun would have less recoil due to the weight than a polymer framed gun further refuting their claim above.

 

I reached out to Trijicon who stated it is the recoil that wears out these optics and that their testing shows that there is no difference in a modular system like the MOS vs a direct milled option. They also rate their optics based on a direct milled testing method resulting in 30k+ round lifetime.

 

 

 

So what does everyone else think?

Which one is more likely, that failures are due to harmonics wear or mostly dependent on round count?

 

How much, if any merit does the plate mitigating harmonics wear and tear have?

 

Is there any merit to the claim that a steel framed gun will put more wear on a slide mounted optic than a polymer frame mounted optic?

 

 

 

 

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Edited April 3, 2020 by hurley326

[AHI]

Have two Glock slides milled for the same optic.

#1 was milled locally and does not have the locator pins milled in just flat

     and held in/on 100% by the screws.This ones sight has failed three times.

#2 was CNC milled with the locator pins and just held down with the screws.

     This ones sight has never failed and currently has three times the rounds 

     fired compared to #1.

 

All plate systems have the locator pins I be-leave this is the key.

[hurley326]

36 minutes ago, AHI said:

Have two Glock slides milled for the same optic.

#1 was milled locally and does not have the locator pins milled in just flat

     and held in/on 100% by the screws.This ones sight has failed three times.

#2 was CNC milled with the locator pins and just held down with the screws.

     This ones sight has never failed and currently has three times the rounds 

     fired compared to #1.

 

All plate systems have the locator pins I be-leave this is the key.

this is a very interesting variable that I did not think of! Thanks for sharing

[teros135]

41 minutes ago, AHI said:

Have two Glock slides milled for the same optic.

#1 was milled locally and does not have the locator pins milled in just flat

     and held in/on 100% by the screws.This ones sight has failed three times.

#2 was CNC milled with the locator pins and just held down with the screws.

     This ones sight has never failed and currently has three times the rounds 

     fired compared to #1.

 

All plate systems have the locator pins I be-leave this is the key.

 

Also, CMore says that the front of the scope should *not* touch the slide; if it does, the slide hammers the scope and causes increased failures.  With a plate there's nothing touching the scope, so fewer forces on it.

[zombywoof]

I have several pistols with dots on them.

 

Two CO guns with adapter plates and Gen 1 Delta points I bought used and put 15,000 plus on each myself. Still going strong.

 

Another CO gun with adapter plate with a Vortex Venom. Not too many rounds, still going.

 

DVC-open with RTS2 on frame mount. First one cracked lens within 30 rounds, second one lasted 4000 then the diode lost some of the image.

 

The slide ride C-more seems to be built like a truck, but kinda big.

 

Just my experience.

 

 

[hurley326]

I have several pistols with dots on them.
 
Two CO guns with adapter plates and Gen 1 Delta points I bought used and put 15,000 plus on each myself. Still going strong.
 
Another CO gun with adapter plate with a Vortex Venom. Not too many rounds, still going.
 
DVC-open with RTS2 on frame mount. First one cracked lens within 30 rounds, second one lasted 4000 then the diode lost some of the image.
 
The slide ride C-more seems to be built like a truck, but kinda big.
 
Just my experience.
 
 

This is just comparing both slide mounted options. Direct milling into slide and then adapter plate on slide. Frame mounted is a different ballpark.


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[Chillywig]

Need to see a quality super slow mo video. Somewhere I saw a high speed vid of an open gun and could not believe how much everything reverberated. Maybe there's a difference when the dot is riding on a slide with locator pins vs no pins? Anyone have a fancy high speed camera? 

[MemphisMechanic]

I have 5,000 or so through a PPQ which has been direct milled for a DPP. Pins are used. The optic fits so tightly into the groove in the slide that it’s press-fit.

 

This is the third gun this DPP has been on. It’s got at least 10-15k on it. Not one issue, just goes and goes.
 

I’ve seen so many guys have issues with the bolts mounting their MOS/CORE/etc plate come loose, or the bolts holding the optic down to the plate.

 

With the optic fitted to the notch so precisely, my bolts se vastly lower load. Never ever had an issue.

 

Edited April 6, 2020 by MemphisMechanic

[Racinready300ex]

On 4/2/2020 at 11:11 PM, hurley326 said:

 

Also on the claim they made on steel frame vs polymer, I would think a steel framed gun would have less recoil due to the weight than a polymer framed gun further refuting their claim above.

 

I don't see how a heavy frame can help the dot. The weight of the frame should have no impact on recoil for the Dot. It changes what you feel, but the dot in mounted to the slide, so slide weight and velocity is what would effect recoil for the dot. Now, if the poly frame flexes at all, in theory that may slightly absorb some force on impact reducing stress and spreading the energy out over a longer time. Is that a real thing? No idea. If so would that help the Dot? Stil no idea.

[shred]

10 hours ago, Chillywig said:

Need to see a quality super slow mo video. Somewhere I saw a high speed vid of an open gun and could not believe how much everything reverberated. Maybe there's a difference when the dot is riding on a slide with locator pins vs no pins? Anyone have a fancy high speed camera? 

 

Yeah, everything wobbles around like it's made of jello on high speed video.

 

Personally I doubt a plate makes much difference one way or the other on the same gun.  It's possible some vibration gets absorbed but I'd guess different guns are much more of the reason.  Saying "plastic guns with plates break dots less than steel guns with direct mounts" has waaay more than one variable in it.

 

 

 

[MikeBurgess]

3 hours ago, Racinready300ex said:

 

I don't see how a heavy frame can help the dot. The weight of the frame should have no impact on recoil for the Dot. It changes what you feel, but the dot in mounted to the slide, so slide weight and velocity is what would effect recoil for the dot. Now, if the poly frame flexes at all, in theory that may slightly absorb some force on impact reducing stress and spreading the energy out over a longer time. Is that a real thing? No idea. If so would that help the Dot? Stil no idea.

Think about it like this, the dot receives 3 shock loads per firing cycle, 1 when the gun fires and the slide starts moving backwards, 1 when the slide bottoms out on the frame, and 1 when the slide stops as it goes into battery. The initial firing shock (assuming similar ammo PF) is directly related to slide and barrel assembly weight, the heavier it is the slower it will accelerate thus the lower the shock load. The slide bottoming out shock is related to slide velocity at impact and frame weight and hardness, a light weight frame will take less energy for the slide to make move and a soft frame will deform slightly allowing that load to take place at a lower level for a longer time ( think about kicking a beach ball vs a base ball, similar weight but very different hardness one will hurt one wont)  Finally the return to battery shock likely the lowest of the bunch by a order of magnitude is also lower and extended in a lighter framed heavier slide gun for the same reasons as the slide bottoming on the frame is.

 

so worst case shock loading is a very heavy metal frame with a very light slide with light springs allowing the slide to accelerate and decelerate very quickly

and best case would be a very light plastic frame with a heavy slide assembly making the slide accelerate and decelerate much slower. 

 

Now all this has nothing to do with what may be the best from a competitive point of view where having a lighter slide on a heavy frame may make the gun feel and track better to some shooters. 

 

That said if I had a steel framed CO gun with a light slide I would want to find a way to add a shock buff to the recoil system if possible. 

 

 

[Racinready300ex]

45 minutes ago, MikeBurgess said:

Think about it like this, the dot receives 3 shock loads per firing cycle, 1 when the gun fires and the slide starts moving backwards, 1 when the slide bottoms out on the frame, and 1 when the slide stops as it goes into battery. The initial firing shock (assuming similar ammo PF) is directly related to slide and barrel assembly weight, the heavier it is the slower it will accelerate thus the lower the shock load. The slide bottoming out shock is related to slide velocity at impact and frame weight and hardness, a light weight frame will take less energy for the slide to make move and a soft frame will deform slightly allowing that load to take place at a lower level for a longer time ( think about kicking a beach ball vs a base ball, similar weight but very different hardness one will hurt one wont)  Finally the return to battery shock likely the lowest of the bunch by a order of magnitude is also lower and extended in a lighter framed heavier slide gun for the same reasons as the slide bottoming on the frame is.

 

so worst case shock loading is a very heavy metal frame with a very light slide with light springs allowing the slide to accelerate and decelerate very quickly

and best case would be a very light plastic frame with a heavy slide assembly making the slide accelerate and decelerate much slower. 

 

Now all this has nothing to do with what may be the best from a competitive point of view where having a lighter slide on a heavy frame may make the gun feel and track better to some shooters. 

 

That said if I had a steel framed CO gun with a light slide I would want to find a way to add a shock buff to the recoil system if possible. 

 

 

 

That's kind of what i was trying to get at when I said if the poly frame flexes it could absorb and spread out the impact. It seems like we are on the same page that in theory the poly framed gun might lessen the impact vs steel. I thought the OP was saying he thinks because steel guns feel softer they would be easier on the dot, which i think the opposite might be true. But, I doubt it's enough to matter either way. If I was running a S2 or similar with a lightened slide I might be more worried about the slide then the dot. 

 

I could see what MM said above about how precisely your dot fits the locating pins on the mount having more of a impact on the dot. 

[MikeBurgess]

2 hours ago, Racinready300ex said:

 

That's kind of what i was trying to get at when I said if the poly frame flexes it could absorb and spread out the impact. It seems like we are on the same page that in theory the poly framed gun might lessen the impact vs steel. I thought the OP was saying he thinks because steel guns feel softer they would be easier on the dot, which i think the opposite might be true. But, I doubt it's enough to matter either way. If I was running a S2 or similar with a lightened slide I might be more worried about the slide then the dot. 

 

I could see what MM said above about how precisely your dot fits the locating pins on the mount having more of a impact on the dot. 

I agree, 

and from a longevity standpoint we all tend to err on the side of performance (or perceived performance) so its all kinda a mute point. If  I had a heavy steel CO gun that I liked but was killing 2 dots a year on it, Id be like ok ill just have some backups and change it before any major match. 

[Racinready300ex]

16 hours ago, MikeBurgess said:

I agree, 

and from a longevity standpoint we all tend to err on the side of performance (or perceived performance) so its all kinda a mute point. If  I had a heavy steel CO gun that I liked but was killing 2 dots a year on it, Id be like ok ill just have some backups and change it before any major match. 

 

True, I just started CO I already have two dots on two slides for one gun. One got used enough to make sure it works and now will only be used for majors. The other gets used for everything else. If it breaks who cares, I'll get it fixed. I'm sure as funds allow I'll end up with another gun and more dots just to be safe. 

[shred]

I looked at a sight-plate mounted dot (SRO, steel frame TF Limited Pro) on 600 and 1200 fps high speed video and saw no sign of flex or movement in the dot versus the slide.  The dot does what the slide does.  This is not the case of frame-mounted Open dots at the same video speeds.

 

There's very little force applied at ignition. (vibration may be a different story.  That's difficult to see on video and can cause all kinds of weird breakages anywhere along the way).  Then there is a strong pull backwards, the sudden stop at the end of travel and the spring forward and ride to a stop there.

 

FWIW, Years ago I put an accelerometer on a Limited gun slide and saw up to 40G peak force at recoil and around half that at closing with a Major spring setup.

 

[Steve RA]

Here is a slide mounted Burris FFIII which has been on for about 5 years.  First FFIII died after about 30 rounds.  Sent to Burris and they sent a new one.  It has lasted very well.

 

[hurley326]

I looked at a sight-plate mounted dot (SRO, steel frame TF Limited Pro) on 600 and 1200 fps high speed video and saw no sign of flex or movement in the dot versus the slide.  The dot does what the slide does.  This is not the case of frame-mounted Open dots at the same video speeds.
 
There's very little force applied at ignition. (vibration may be a different story.  That's difficult to see on video and can cause all kinds of weird breakages anywhere along the way).  Then there is a strong pull backwards, the sudden stop at the end of travel and the spring forward and ride to a stop there.
 
FWIW, Years ago I put an accelerometer on a Limited gun slide and saw up to 40G peak force at recoil and around half that at closing with a Major spring setup.
 

This is in regards to both slide mounted optics, no frame mounted comparison. Slide milled direct for optic versus slide milled with a plate adapter system for optic.


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[shred]

Yeah, I'm just pointing out that you can easily see flex in a frame mount at 600 and 1200 fps.   So, not-seeing any in my video at the same frame rates (same camera even) on a slide mount says there's no noticeable flexing going on with a slide-mount plate and so likely no different than an equivalent direct mount.

 

If there is any difference between the two on the same slide (which I am unconvinced of, I suspect firearm differences (make, model, load, springs, etc) greatly outweigh any plate-vs-direct effect) it could be from vibration.  A plate could possibly provide some level of vibration attenuation, but I can't see any effect of the plate otherwise.

 

[Racinready300ex]

2 hours ago, Steve RA said:

Here is a slide mounted Burris FFIII which has been on for about 5 years.  First FFIII died after about 30 rounds.  Sent to Burris and they sent a new one.  It has lasted very well.

 

 

 

What kind of round count? 5 years around these parts could mean 5k rounds it could mean 250k rounds.  I see a lot of people talk about slide mounted optics dying after 10-15k rounds.

[Racinready300ex]

1 hour ago, shred said:

Yeah, I'm just pointing out that you can easily see flex in a frame mount at 600 and 1200 fps.   So, not-seeing any in my video at the same frame rates (same camera even) on a slide mount says there's no noticeable flexing going on with a slide-mount plate and so likely no different than an equivalent direct mount.

 

If there is any difference between the two on the same slide (which I am unconvinced of, I suspect firearm differences (make, model, load, springs, etc) greatly outweigh any plate-vs-direct effect) it could be from vibration.  A plate could possibly provide some level of vibration attenuation, but I can't see any effect of the plate otherwise.

 

 

That is the only thing I can imagine it would be, but i don't know how anyone could prove it one way or another due to all the variances you mentioned in your post. I've heard people make this observation, so maybe there is something here but who knows. 

[Steve RA]

19 hours ago, Racinready300ex said:

 

What kind of round count? 5 years around these parts could mean 5k rounds it could mean 250k rounds.  I see a lot of people talk about slide mounted optics dying after 10-15k rounds.

 

Probably around 10K, mostly self defense type loads as it didn't fit any class other than open - which I never shot it in.  The guns does shoot well with the dot.

[Racinready300ex]

22 minutes ago, Steve RA said:

 

Probably around 10K, mostly self defense type loads as it didn't fit any class other than open - which I never shot it in.  The guns does shoot well with the dot.

 

 

That gun should be legal in IDPA CO if you wanted to shoot it in something. 

[Steve RA]

1 minute ago, Racinready300ex said:

 

That gun should be legal in IDPA CO if you wanted to shoot it in something. 

 

Never been interested in IDPA - but thank you for the suggestion.