So I’m a Marine and we just started getting the M18 issued (within the last year). I just shot the pistol range today with it for the first time. Some observations I noticed and speaking to the coaches and armorers are common issues:

By far the most common seems to be that the rear sight gets loose and is sometimes thrown from the slide. This seems to me like a non issue that a little loctite wouldn’t fix on the set screw. It seems they should definitely come from the factory like that since 99% of issues pistols will only have the factory rear sight their whole life.

Failure for the slide to return to battery. This issue is apparently very common and happened to a shooter today (1 of 5 shooters). I think this is part limp wristing but also the pistol itself. From previous ranges with the M9, this was extremely rare. It probably helps that the M9’s were thirty years old, but I think the M9 is a smoother pistol in general.

Stiff mag springs that prevent loading a full 17rds. I think this is pretty dumb but the armorers are recommending loading only 15-16 rounds like was recommended for early M16 mags.

O ring on the disassembly lever getting lost. Apparently this is very common and is very frowned upon to lose it. It’s analogous to the firing pin retaining pin on an AR. They are the most often lost component.

Anyways those are the observations I’ve noticed and what the armorers told me. They all seem to think the M18 is “fragile” compared to the M9. The scores from the ranges have been better than with the M9. The ability to swap grip modules is making the most difference. For me personally, I’ve shot better with the M9. I’ve always been expert but my score dropped about 10 points with the M18 versus the M9. I’ve always enjoyed the M9 though and used to shoot USPSA with one.

They should have never put the rear sight on the optic plate.  I think they realized that and new civilian models are starting to focus on a slide cut rear iron.

Its an issue with factory fresh pistols.  The barrel and slide lock up is really tight at the breach.  It works it self out pretty quick.

Weak hands.  Nothing prevents 17 rounds except freshly done nails and soft thumbs.

I've never heard of this.  I recommend IQ test for people this happens to.  Retards shouldn't be allowed to have guns.

Certainly not a perfect gun.  The lock up tightness is a pretty big deal if you're new to Sigs and don't run the slide a couple hundred times before shooting.

Have you never met a Marine?

Yes, and I know its too much to ask them to "just don't fuck this up, you don't have to do anything other than that."

I figure they'll get along with the M18 just fine still.

grunts shouldn't be pulling the takedown lever out at all, there's no reason for it. In my approximately hundreds of times doing it myself, I've never had an oring come off... or rip... not even once.

Post 1776

Coulda been better Leatherneck

Damn you’re right. Coulda been a great opportunity.

In regards to the o ring thing, the student handout released by marcorsycom has removing the fcg (they call it a receiver) part of the disassembly procedures. Link is below to the pub. This handout also includes the information about the o ring being commonly lost.

https://www.lejeune.marines.mil/Portals/27/Documents/WTBN/MTU/Preparatory%20Classes/M18%20Operator%20NET%20Student%20Handout%204-2020%20Signed.pdf?ver=JTfycEW6x6R2JyK1dGtrJg%3d%3d

I have just over 1k rounds through mine and have never experienced any of that . But then again I was Army.??

I hear you. I personally owned an M18 for about a year and had probably 500rds through it. I never had an issue except for some sporadic rust on small parts. This is probably due to me carrying the pistol a lot including while on a saltwater boat here in SC. Always kept it well lubed, but for whatever reason, the M18 phosphate small parts rusted extremely quick. I made an awesome trade a few months ago for a brand new FN Five Seven. I miss my M18 and will probably pick on up again.

The one thing I am pleasantly surprised about the M18 adoption is the actual use of the different grip modules. I assumed when this pistol was adopted that the grip modules wouldn't actually be used and that the medium grip would be the only one actually issued. I figured the small and large would sit in a box to never see the light of day. I am surprised that the different size grips are actually offered and they are actively being switched out to fit different Marines.

One of the two surplus M17s I purchased came with the small grip. I have fairly big hands and was surprised at how comfortable it is.

Quoted:
So I’m a Marine and we just started getting the M18 issued (within the last year). I just shot the pistol range today with it for the first time. Some observations I noticed and speaking to the coaches and armorers are common issues:

By far the most common seems to be that the rear sight gets loose and is sometimes thrown from the slide. This seems to me like a non issue that a little loctite wouldn’t fix on the set screw. It seems they should definitely come from the factory like that since 99% of issues pistols will only have the factory rear sight their whole life.

They should have been locktited from the factory.  I personally have not seen one come loose, but it could happen, especially with a high round count, and no one checking the screws.

Failure for the slide to return to battery. This issue is apparently very common and happened to a shooter today (1 of 5 shooters). I think this is part limp wristing but also the pistol itself. From previous ranges with the M9, this was extremely rare. It probably helps that the M9’s were thirty years old, but I think the M9 is a smoother pistol in general.

Limp wristing could cause it, but could just need to be broken in a bit.  This isn't a common problem with the 320 in general.  

Stiff mag springs that prevent loading a full 17rds. I think this is pretty dumb but the armorers are recommending loading only 15-16 rounds like was recommended for early M16 mags.

Yes they are stiff when new, nothing shocking here.  Suck it up and put the 17 rounds in it and it will loosen up.  Sore fingers build better shooters.  

O ring on the disassembly lever getting lost. Apparently this is very common and is very frowned upon to lose it. It’s analogous to the firing pin retaining pin on an AR. They are the most often lost component.

This is not a common problem anywhere.  Tell your folks to stop fingering the o ring.  It  doesn't come off the take down lever very easily, and certainly doesn't fall off.  Your guys are finger banging it, and loosing it plain and simple.  The only one I have ever replaced on a 320 was because it was cracking and wearing out.  This was also on a pistol with 15k rounds on it.

Anyways those are the observations I’ve noticed and what the armorers told me. They all seem to think the M18 is “fragile” compared to the M9. The scores from the ranges have been better than with the M9. The ability to swap grip modules is making the most difference. For me personally, I’ve shot better with the M9. I’ve always been expert but my score dropped about 10 points with the M18 versus the M9. I’ve always enjoyed the M9 though and used to shoot USPSA with one.

I'm a 320 Armorer as well and service a lot of 320's at my department as well as other agencies in the area.  None of these issue have shown up, nor have they been talked about in the multiple armorers course I have been to.  

PS, I was in the ARMY as well, and yes I do like the M9 also.    :)




TXPO

The thing about loading mags to 15 or 16 was stated for reliability purposes, not really cause they're hard to load. Pretty much the same reason why they still say to load 28 rounds in rifle mags (even after we got issued Pmags). It's just kind of a thing that consistently gets passed down to the next generation of Marines. I always say it's dumb but they still do it.

If they issued them with your choice of S-M-L X-series grip shells I bet everyone would be happier.

Neat observations OP, I prefer the M9 to the sig p320 in any format as well.

You or whoever instructed you is misquoting the handout. It states that the O-ring is the most commonly replaced(not lost) part in the receiver take down instructions. Also note "most commonly" is a relative term and does not equal "commonly," "oil is the most commonly replaced wear item in your car" does not mean oil is commonly lost, just that you need to replace it more often than say... your tires. It's a note, not even a caution. in the reassembly portion there's a note to check and make sure the O-ring is there as well.

The rear plate issue is DoD wide. I had my guys running 25 quals a day, on the first day we had nearly 20 plates come off or loose.

Loctite fixes it easily enough but Sig was sloppy letting the guns out the door in the first place.

I switched the medium size out for the small one and I like it ALOT better on my M18.

Most infantry (as with LEOs) are not gun people.

I was US Army and LEO decades ago and the lack of understanding, experience and just giving a shit about knowing your weapon and practicing with it was always a source of amazed confusion for me.

How can people who carry a gun for possible daily use in a life threatening situation know so little about how it works, how to keep it working, and how to hit what you need to hit with it be so damn uncaring about that weapon(s).

In the US Army only two guys in my platoon took an interest in the pistols (1911s) and shotguns (Win. M1200) in the armory.  Only two of us went to a civilian range at every opportunity to practice with handguns and rifles (not out 1911s and M14's unfortunately - but I bought a 1911 and an M1A before I got out of the Army).

As a LEO only three of eight of us practiced regularly with our handguns.  The other five guys could care less.  Even stainless S&W revolvers were neglected to the point where the cylinder would lock up on the crane from lack of lube.  Fifteen shot 9MM semi auto pistols were carried with six rounds in them and no back up mags. on the duty belt.  .38 special ammo was left in the drop pouches so long the ammo was covered in corrosion and could not be chambered when it was eventually removed from the drop pouch (dating myself with that one, ain't I).  Holes were shot in office walls with "empty" revolvers.  

That's just the way it is, right or wrong.

Yep. I had the same experience in the Infantry. I couldn't understand it, either.

We're dealing with the failure to return to battery and the rear sights coming off on the Air Force side.  What our small arms functional at the MAJCOM is being told is that the failure to return to battery issue is due to the rear slide plate that holds in the striker being slightly out of spec. We've been replacing the intermittent ones with commercial plates and it seems to solve about 90% of the issues, the rest wear in.  

 The rear sight thing might be partially an armorer issue, one of the old TO/FMs had a step in the receiving inspection that called for the rear sight plate to be removed, inspected, and replaced.  Per the armorers course, once you remove the rear sight, you're supposed to replace it.  I would hazard a guess that once the "receiving inspection" is done, the plates aren't torqued or loctied in again.  They put out a NOTAM on the rear sight problem within the last 5 - 6 months and changed the TO.  

Whoever is the tech writer needs to redo the Loading instructions.

M18 Pistol Loading.
(1) Press up on manual safety lever to engage safety.
(2) Lock slide to rear by pulling slide to rear while pushing up on slide catch lever.
(3) Conduct three-point safety check to ensure there is no cartridge, foreign debris, or any physical
damage.
Ensure chamber is empty
Inspect for no magazine
Inspect breech face

(4) Insert an empty magazine into magazine well. You should hear an audible click.  

(5) Release the Slide catch lever forward, chambering a cartridge.

Line 4 should read Loaded magazine

M18 worth it? Heading up to SIG tomorrow to check them out...

Engrish prease...

I like mine.  Have had no trouble with it at all.

Attached File

I’d say so. Oddly (to me) the civilian sold M17/18’s do not seem to have the issues DoD pistols suffer from.

I caved. Not disappointed. I ended up removing the manual safety and putting the small grip module on. It's without doubt the best "feeling" gun I've handled in quite some time.