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Brian Enos's Forums... Maku mozo!

Slide mount or frame?


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Do you have trouble tracking the stock iron sights?

If not, then you shouldn't worry about tracking the dot mounted to the slide.

Just my $0.02

Agreed plus...

Here is something else to think about. Having watched slow motion video of comps at work I noticed that even the best have some small amount of muzzle rise, followed by a small amount of muzzle dip when the slide closes. The center of the guns rotation (CG) during recoil is directly above your hand. Just like a teeter-totter the farther down the arm you extend beyond the pivot point (say a frame mounted optic on the other side of the ejection port) the greater the up-down motion will be. In theory, with a slide mounted red dot directly over your hand and slightly forward of the center of rotation, the dot's up-down movement would be less. Same degrees of rotation, but a shorter arm of rotation (1.5" forward of CG in battery to 1.5" rear of CG during ejection). As a result as the slide moves to the rear, and then back forward, the sight window should not lift or dip enough for the dot to leave the window (assuming a proper hold, a good comp and the right load).

Weight x arm = moment so the farther down the arm from the CG the greater the moment the sight will have on the gun in recoil (simple leverage). A frame mounted C-More Slide Ride (not STS) may put a few onces forward to help with recoil. However at a little over an ounce weight from an STS (plus the weight of the mount) it should not be a real factor.

With that said, I am building my G17 as a slide ride with a 7 MOA STS. If you have the correct weight recoil spring, and your ejector/extractor are tuned right, the brass shouldn't hit the STS or you.

Just my $.01 after taxes...

AFTER THOUGHT: The slide to barrel fit on Glocks is very good so the dot and barel should re-zero shot after shot. However, being a combat gun the slide to frame fit is a bit loose, and that means the dot may not always realign with the barrel when returning to battery. Unless you plan to have the slide to frame fit tighened to eliminate the slop, the slide mounted optic should be more acurate shot after shot. In addition the Carver mount is bulky and requires a modified CR-Speed holster, the STS micro dot mount requires drilling and counter boring holes in your frame for installation. IMHO the slide mount is the cleanest, most accurate and easiest way to mount the dot.

Now we're up to $.02 worth.

Edited by wmspdi
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Does the extra weight of the optic enter in if it is a slide ride in any of the tuning or tracking issues? Or is it really a nonissue?

The optic only weighs .9 to 1.7 oz depending on make, model and mount. Going from a plastic Glock rear sight to a steel adjustable iron sight (say a Millet sight) would be about the same change in mass. If you sense a slight change in slide velocity you can either adjust the slide spring weight (down a pound), have the sight "melted into the slide (the steel removed should equal the weight of the optic), or mill out a little steel (coffin cut) from the top of the slide.

The coffin cuts behind the front sight on the G34/G17L/G24/G35 slides are there to lighten the longer slide's mass to be close to that of the G17/G22. That is how all 6 guns can use the 17 lb factory Gen 3 spring. Since the optic is directly over the CG (your hand) the balance should not be effected.

Edited by wmspdi
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If mounting to the frame is an option, I would do that. I've seen many slide mounted optics break. I just don't think the soldering points were ever designed to be slammed back and forth. In speaking with friends, we've broken them all. Burris, Trijicon RMR, Pride Fowler, Aimpoint Micro. The only one that has lasted thus far is the fiberoptic/tritium Trijicon RMR (the one with no electronics).


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I went with the SJC Frame mount. I tried the slide mount and just found it awkward. My buddy shoots one of the slide mounted ones. He likes it just fine.

If you can try both, I would suggest it.

One advantage to the slide mount is the holster options are much greater.

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There is no doubt that the early slide mounted dot optics were not built to the standards of the new units. The manufactures learned what to redesign through field trials conducted by their "paid beta testers" (those paid beta testers would be all of the shooters who bought those early designs and thus paid for the privaledge to test them). To break one of the newer slide mounted optics (C-More STS, JPoint, Fastfire III...) rated at 1,000Gs of shock you would have to be running an extremely light recoil spring (to get very fast slide cycling). The mass of the slide would be slamming hard against the frame at the rear of travel. I would be more concerned about slide/barrel/frame battering with that much recoil energy, than I would be concerned about breaking the optic.

The newer optics (like the JPoint) have the electronics sealed in a block of resin. Switches have been redesigned or eliminated. Optic designs (like cell phones and computers) change every 12 to 18 months. The Fastfire II is not that old, yet the Fastfire III ships out this month. The dot on your gun today will soon be obsolete and you will be looking for the next to piece of new technology to replace it.

I consider red dots like the Fastfire II ($200) JPoint (at $250) or STS ($300) to be expendable. They are priced to be upgraded, or replaced when worn, like magazines or compensators. Run it till it breaks, then just replace it (hey, it may still be under warrenty anyway). If it still works when you upgrade to a new optic save the old one as an emergency replacement. If they use the same mounting plate all the better.

As far as which style mount you like better... it's no different than black post vs fiber optic vs big dot front iron sights. Everyone's taste is different.

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Placing a cmore RTS on my g17 and wanted to get some opinions of both ways of mounting it.

BTW- I should have noticed this earlier. :blush:

Unless I am missing something... I believe the RTS is only available in a picatinny mount.


Your only mounting options for the RTS would be a frame mount on a picatinny rail, or having a picatinny rail and cross slot milled into the rear of your Glock slide (Lone Wolf offers this style cut on their own slides, but not on Glock OEM slides).


To mount the optic in the dovetail on the slide you would have to use a C-More STS with a Glock narrow mounting plate. Sorry I didn't catch this earlier.

Edited by wmspdi
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