I have been trying to buy a slide without the LCI, and am not finding much. Is Sig now shipping most 320's with the LCI?

I don’t believe so. Here in CA they are mandatory but I’ve always been under the impression that outside the M17/M18 models the LCI was gone.

What size slide are you looking for? Here is the compact Xseries slide from SIG (no lci in it):



XSERIES (OPTIC READY) SLIDE ASSEMBLY - 9MM - BLACK NITRON 3.9

You can try looking on Gunbroker for a complete slide assmbly but usually they are priced similarly to the factory prices. Also search for P320 repair parts and there are parts available for complete pistols minus the FCU but you have to make sure these slides are from post upgrade guns to work with new FCUs.

I am going to call Sig on Monday, they have a few slides that do not have the LCI, but many new P320s appear to have it.

I don't think anything except the M17 and M18 have the slide with the LCI in it. Most new 9mm models with the standard length 4.7" and 3.9" barrels may have the notch in the barrel hood but the slides don't. I think that's just because Sig standardized on one type of barrel for inventory purposes. I think the Gold Titanium-Nitride finished 9mm barrels are the only standard length barrels they sell now without the LCI notch.

quote:

Originally posted by c1steve:
I am going to call Sig on Monday, they have a few slides that do not have the LCI, but many new P320s appear to have it.

You say: “Location: West coast”. If than means California, I doubt that SIG will sell you a no-LCI slide. I tried, unsuccessfully, to buy such for my CA P238.

I just bought a P320c 3.9 in. slide in FDE with the optics cut from Sig. It was on sale for $225.00. It doesn’t have an LCI. I did note that a new 3.9 barrel came with the LCI cut so I decided to continue using the original barrel that came with my P320 that I bought in 2018.

LCI?

Loaded Chamber Indicator

When we are referring to the loaded chamber “indicator,” is it the actual lever that pops up when a round is chambered, or just the slot in the barrel hood extension that doesn’t actually indicate anything, but may satisfy that requirement?

quote:

Originally posted by smschulz:
LCI?

thanks for asking... I was having a hard time processing this thread too... not a fan of abbreviations until after they are defined.

What am I missing here?

What's the liability of a loaded chamber indicator as on the USGI and California pistols?

-- Chuck

Ideally all your same size P320s would be identical, so you could swap barrels, etc., if you wanted. Also more parts mean more to go wrong and more to clean. There have been remarks that the gasses slipping through the space between the LCI parts and the slide cause a dot sight to need much more frequent cleanings.

"Parts left out are less expensive and cause no service problems". Famous GM engineer Charles Kettering.

A suggestion would be to get a pro cut slide if you like the looks. No LCI and comes optics ready. Get a CHPWS filler plate if you are going RMR footprint. Otherwise keep searching. No restrictions on slides but vendors can be picky about shipping to CA.

Neither the barrel nor slide on my sub-compact are LCI cut.

quote:

Originally posted by c1steve:
There have been remarks that the gasses slipping through the space between the LCI parts and the slide cause a dot sight to need much more frequent cleanings.

SIG does seem to feel that’s a legitimate concern. The new ROMEO-M17 optic has a small lip below the front window to deflect the gas coming out of the LCI.

Based on previous discussions, I didn’t think it mattered if the lenses/windows of optical sights on handguns got dirty. Isn’t there some way for the knowledgeable and experienced shooter to compensate for not being able to see through the sight clearly? I’ve raised this question in regard to the sight’s being blocked by rain, snow, or other foreign matter and it was usually just ignored or dismissed with a vague, “Oh, it’s not a big deal in the many times it’s happened to me,” comment. Does a little blowback soot matter or not?

And I’m still curious about what loaded chamber “indicator” refers to in the original question: just a hole in the barrel hood extension, or an actual part that gets pushed up and truly indicates that there’s a round in the chamber? It’s been some time since I’ve seen a new SIG barrel without the hole, but what’s the status of the real indicator?

quote:

Originally posted by sigfreund:
Isn’t there some way for the knowledgeable and experienced shooter to compensate for not being able to see through the sight clearly? I’ve raised this question in regard to the sight’s being blocked by rain, snow, or other foreign matter and it was usually just ignored or dismissed with a vague, “Oh, it’s not a big deal in the many times it’s happened to me,” comment. Does a little blowback soot matter or not?

I didn't realize no one has ever answered your inquiry, as the answer is rather simple.

1. It matters if it bothers you to look through the blowback. Some folks are distracted by the appearance of "stuff" on the lens and can't look pass it. It is much like light rain drops on your windshield. Some folks look though them and jokingly say they are "looking between the drops" and others have to immediately turn on the wipers to smear the dirt around.

2. There is no need to compensate for a blocked sight unless you aren't shooting with both eyes open .
a) The eye looking at the screen continues to see the dot.
b) The other eye is looking around the lens and continues to see your target.
c) Your brain puts the two images together and allows you to put the dot on your target

Functionally it doesn't matter, but it is annoying, especially if you are the sort who appreciates having things clean. And it just adds insult to injury when the problem is exacerbated by some pointless nanny-state "feature" that shouldn't be on the gun in the first place. Even if I wasn't planning to mount an optic I wouldn't want that stupid LCI (or even just the cut) on my gun.

quote:

Originally posted by 9mmepiphany:
2. There is no need to compensate for a blocked sight unless you aren't shooting with both eyes open .

That’s a good, valid point that I’d frankly forgotten about.
The probable reason for my forgetfulness, though, was the state of my vision for well over 50 years of my life: I was very nearsighted in my left (nondominant) eye, and therefore if I couldn’t see through an optical sight with my right eye, precise aiming was not possible.* Admittedly that condition is probably true of only a small percentage of shooters, but it is something for a few of us to be aware of.

* That is no longer true because the vision in my left eye has changed over the past few years so that I now have good distant vision with it, about 20/25 as compared with 20/20 (or better) with my right.

More important, though, is this:

quote:

Originally posted by 9mmepiphany:
c) Your brain puts the two images together and allows you to put the dot on your target

The brain does indeed allow us to “see” the dot with the eye that’s not looking through the sight, but does the apparent position of the dot remain in the same place?

I have only one optical sight suitable for mounting on a handgun, an ACRO P-1. Lest anyone think I don’t take seriously the comments of those whom I respect, I set the sight up on a tripod and experimented with one eye/two eye aiming. The gun was firmly clamped in place and my eye was at arm’s length from the sight.

I started by aiming with my dominant eye at a spot 10 yards from the sight, and everything was rock steady. Then, without moving anything, I covered the front of the sight, and what happened? Although I was still seeing an image of the dot reticle with my right eye and clearly seeing the target with my left (that now has good distant vision), as soon as I covered the sight the apparent position of the reticle immediately shifted about 1 foot to the left, and totally off my original point of aim.

This result is something I seemed to recall when using another Aimpoint in the past, and so tried the experiment with a CompML3 sight mounted the same way. With the rifle fixed in position and aiming at a point a couple of hundred yards away, the apparent position of the reticle shifted several feet from its original aiming point. Had I been trying to use the superimposed reticle position while having the front of the sight blocked, it would have resulted in a gross miss.

Note that this shift in reticle position occurs only when using the superimposed image of my left eye looking at a distant point and my right eye seeing the reticle. It does not occur when looking through the sight with either right or left eye; the reticle remains in exactly the same place as it should. I tried the experiment several times with both sights and the apparent reticle shift position occurred every time. The effect is greater the farther the point of aim is located, and seems to vary somewhat with head position behind the sight. At a couple of feet the shift might not matter for hitting a human sized target, but even a foot at 10 yards is another matter.

Furthermore, in thinking back to the times I tried using the superimposed vision technique with my rifle in the now-distant past, the bullet impact points were significantly displaced from where I was aiming. At the time I chalked it up to my poor left eye vision, but now I believe I know the true cause.

I don’t know the optical cause of the shift in reticle position when using my superimposed vision. Perhaps it has to do with something pertaining to parallax or the designs of the two sights I tested. It may also vary with the individual, although that seems unlikely. It would be very interesting to learn the results of anyone else’s experiments. But there’s no doubt that it would have, and probably has had a significant effect on points of impact with my sights.

Added: As an additional test, I tried the experiment with a Leupold “Prismatic” sight and a point of aim a couple of hundred yards away. When switching from aiming with my right eye through the sight to blocking the sight and using the superimposition of reticle seen with my right eye and viewing the target with my left, the reticle apparently shifted position by many feet. So the phenomenon isn’t limited to Aimpoint sights—at least not for me.

And all that is not about using an “occluded eye gunsight” that relies entirely on the superimposition of two visual images using a sight that deliberately blocks the view of one eye except for the image of an illuminated reticle while requiring the use of the other eye for target viewing. With that sight there is no reticle image shift when the sight is blocked because the system is intended to be used that way. I have no experience with that type of sight, but if it’s zeroed with the one eye occluded all the time, then everything would remain the same all the time.

And another. I repeated the above test with a conventional 3-15× scope under low light conditions so I could see the illuminated reticle as well as a point light source about 200 yards distant. The rifle was mounted on a tripod with the reticle firmly aimed at the light that I could also see with my nondominant eye. Whenever I closed the front lens cap I could still see both the reticle and the light, but the apparent reticle position consistently shifted left about 3.0 milliradians, or about 22 inches at that distance.

This message has been edited. Last edited by: sigfreund,