New Shadow 2 - break in question about slide lock

[bikeinxs]

Took my black badge course in February and it was suggested by my instructor that I upgrade my M&P 2.0.  I've now had my Shadow 2 to the range twice and I am blown away by the accuracy.  My groups are half the size they were.  The gun was flawless on my first range outing (maybe 300 rounds), but on my second outing the slide would not lock open when I emptied a magazine.  If I manually pull the slide back on a empty mag it locks open.  I have to confess I did not clean the gun between outings.

It was suggested to me by a club member that (a) I needed to make sure the rails were well lubricated and (b) this would resolve itself with time.

I am using factory Winchester 115 grain ammo.  I have not made any mods to the firearm.

Thanks in advance.

[m1a_scoutguy]

Every gun is different but hell I never clean my S2 and it runs fine, NEVER had a malfunction of any kind! I will lube it up every couple range trips but just don't do a full clean that often, I easily go 6/700 rds or more in between full-blown breakdown and clean. Yes keep it lubed for sure, I always say a wet dirty gun is always better than a clean dry gun !! Check it over good, watch your grip & maybe change up your ammo if ya need! Keep us posted!   

[adrian]

     Hiya bikinxs and thx for your thread. And glad to hear to are enjoying the S2 except for the little hiccup. And I'm sure operators will chime in as to trouble shooting, as I shall as well.  But first most,and with any stoppages/miss functions,if happening at range,see if range officer can offer a solution. Take a pic for us when appropriate just in case. And then if 9-5pm, call cz-usa and ask to speak to a smith,and get proper advice,you paid for it already,so utilize it.
     When I was breaking in a gun,I would clean it proper with each outing,and after a case or two get a little more lack and maybe stretch to two or three outings. With your gun being still broken in, I'd clean it each outing. Don't use grease to lube,and dry lubes preferred on mags if you need to lube em at all.The grease can attract gunk that could be "at cause" of your hiccup. In my area the federal 115gr was actually cheaper that the WWB and suggest you try it. If not S and B is pretty clean.Ironic that they call it white box,as its the dirtiest ammo I've run across for 9mm, leaving more fouling in the gun,and even the ammo itself is dirty.
     If ya get a chance to ,before next outing you can check the magazine for proper function with respect to the slide lock by removing the slide and the magazine,verifying the slide lock moves freely up and down without sticking and then slowly inserting the EMPTY magazine to observe that it engages the slide lock and forces it upward as the magazine locks into place. Clear as mud?
     Mark mags with a number to notice if a particular mags the culprit. I've seen weak mag springs cause it also, and mag followers. And all else fails cz-usa will look at all that and more if it keeps occurring. Be well.

[Luvdog]

Did it do that with multiple mags or the same mag?

[Kaibab270]

It could be a bunch of things. I'd first guess that the weak Winchester ammo isn't fully cycling the slide since it works when manually pulling it back. But since it worked the first outing I'd have to agree with the above that there is some gunk built up somewhere probably from factory grease causing a sluggish slide on top of the weaker wwb ammo.

[Matt101]

S2?s don?t need any breaking in.

I?m guessing you were riding the slide stop


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[Rmach]

S2?s don?t need any breaking in.

I?m guessing you were riding the slide stop


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Good guess IMO. 

Try some different ammo that has a little more power than WWB.  Grease the rails and manually work the slide lock a few hundred times with adequate oil. If you are not riding the slide stop, and these other suggestions don't work, you can order a lighter recoil spring or send it back to CZ.  Your S2 should run ok with WWB, but I don't like WWB.

[2morechains]

Try cleaning your mags. I clean mine more often than I clean my gun.

[Hemiscorpius lepturus]

I have experienced slide lock failures for the following 3 situations:

1: riding the stop.
This does not happen on all pistols because of the size and shape of my hands, but it has happened once.

2: excessive lube on the slide to stop interface.
Happened on an FN509, excessive oil from the recoil assembly made its way out the gun through the gap and got all over the slide, stopped locking back at that point, you do need lubrication there, but not IN the gap on the slide where the lock engages, and barely any is needed

3: weak ammo.
Magtech ammo specifically, in duty pistols mostly, the slide does not travel back far enough to lock, and in some guns will stovepipe. Other weak ammo will do the same, simple physics, No problems with other ammo I have used, but I only use quality rounds, including 115gr Winchester. In the S2 I have also used Browning BPT 147gr, and possibly Fiocchi 115gr.


Additionally, the following can occur but I have not experienced it:

4: Weak mag spring or drag on follower.
If the follower is not able to push up the slide lock in time due to reduced spring force or friction, it can cause lock failure. With only 300 rounds, it is unlikely this is the problem, but still possible

5: Lack of lubrication on the firearm.
Also unlikely on a new gun with only 300rds, but excessive friction can slow down the action to where it can experience malfunctions. I have used no lube on occasion (Sig P365) in order to see where manual work needs to be done to smooth out the action, the S2 should not require this at all. I use grease on the barrel, and the slide interface, and where the hammer meets the sear, as well as the slide lock where it meets the barrel and frame. Oil on the springs and action pins. Both Milcomm.

6: Damage to gun or mag.
Very unlikely at 300rds