The Beretta CX4 Thread
- Thread starter AgentFoxMulder
- Start date
Here's mine. Cowitnesses perfectly
Nice, I just did the same. Did you need lock tight for the 9mm recoil?
Okay CX4 experts, answer me this: why does my cx4 (9mm) not reset the trigger on every last round, in every mag? I can shoot 9 rounds, lickety split, but when the bolt closes on the last round, the trigger has not been reset. No problem with feeding the round, just trigger reset?
I am running the Sierra papa trigger upgrade, and have about 1000 rounds on that upgrade - no problems. The last range trip I had, was when I experienced the fail to reset issue.
In fairness, I probably have about 600 rounds thru it this last period, without cleaning it, but that's not a horribly large number.
School me, CX4 wise ones!
I am running the Sierra papa trigger upgrade, and have about 1000 rounds on that upgrade - no problems. The last range trip I had, was when I experienced the fail to reset issue.
In fairness, I probably have about 600 rounds thru it this last period, without cleaning it, but that's not a horribly large number.
School me, CX4 wise ones!
Does it do the same thing if you load less rounds in the mag or the full 10 rounds? I have no idea why it would only happen on the last round not any others.
- Location
- chilliwack BC.
that sounds like when I was installing and setting up my Sierra Papa stuff. It happened more, and all the time nearly, but I think its the same cause.
Its not that its not resetting per se, but being jarred loose by the bolt.
Did you install the little stainless shim down near the bottom at the back of the trigger group "bathtub" thing? The hammer(?? trigger, sear, I forget) ,hooks under it. I didn't and it did this. I thought my trigger would be too tight with it and it worked well when racked by hand, or with dummy ammo, but with live ammo I experienced this kind of failure.
Its not that its not resetting per se, but being jarred loose by the bolt.
Did you install the little stainless shim down near the bottom at the back of the trigger group "bathtub" thing? The hammer(?? trigger, sear, I forget) ,hooks under it. I didn't and it did this. I thought my trigger would be too tight with it and it worked well when racked by hand, or with dummy ammo, but with live ammo I experienced this kind of failure.
- Location
- chilliwack BC.
shoot all the normal ones, and then see if the hammer has fallen already. that was how I figured out mine.
I also shimmed the "bathtub" trigger housing at the front to keep it from moving in the receiver. Just a piece of card stock and it works like a hot damn.
I also shimmed the "bathtub" trigger housing at the front to keep it from moving in the receiver. Just a piece of card stock and it works like a hot damn.
I just ordered a CX4 - should be here in a week or so. What ammo are you guys using? Any issues with FN or HP or any particular ammo that is known to have issues? Is +P ok?
Ideally I'd buy a few boxes of 50 but there aren't that many choices around here so I'd like to order a case from one of the site sponsors.
Ideally I'd buy a few boxes of 50 but there aren't that many choices around here so I'd like to order a case from one of the site sponsors.
I have shot mostly FMJ in mine but have shot hollow point with no issues. Beretta doesn't recommend +P ammo for extended shooting sessions. I am sure it will handle occasion shots of +P but they don't recommend using it.
Thanks for the info. Is that recommendation against +P in the owner's manual? So NATO spec ammo is +P, correct?
Edit - I found a brochure for the NATO spec ammo I was looking at and it is +P at just over 38,000PSI compared to 35,000 PSI for SAAMI spec 9mm Luger.
Edit - I found a brochure for the NATO spec ammo I was looking at and it is +P at just over 38,000PSI compared to 35,000 PSI for SAAMI spec 9mm Luger.
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Page 66 of the user manual:
"Warning: the extended use of +P, +P+ ammunition may decrease the minor components service life expectancy. Do not use sub machine gun ammunition because the chamber pressure may reach or exceed proof load pressure". End of quote.
I wouldn't worry overmuch about +P/NATO spec ammo: sure, Beretta said they don't recommend it. But I have a nagging suspicion this is a case of CYA from them. With the number of CX4 owners out there, it's a certainty someone's doing it and I haven't seen many reports of something breaking in a CX4 yet.
Take the following with a large grain of salt, because I'm no mechanical engineer or armourer:
One thing to remember is that the CX4 is a straight blowback design. The breech block is not locked or delayed on firing, so there's not so many pieces that have to take the recoil forces for a few milliseconds until the chamber pressure decreases. That's in part why the fired cases come out dirty as hell, I think: the chamber is machined with relatively loose tolerances to help with smooth extraction.
The extractor (#28) and ejector (#29) are metal, only the hammer (#42) is a hard polymer and stands in the way of the recoiling bolt. There's possibly some flex in the recoil spring guide (#20) when the bolt moves back and forth, I suppose. I could see those parts having a shortened life expectancy from using hot ammo, but none of them have been reported broken yet AFAIK. The spring guide assy is about US$32, the hammer US$26 at Brownell's. The slides in that guide the bolt movement are polymer, but the movement is linear,just friction over them. They're not taking the recoil forces so those don't worry me.
This being said, there have been a few reports of cracked trigger housings (#33) in some Cx4 around 2014, nothing before then and nothing after that time, to it looks like the factory had a bad batch of housings go through QC and fixed that problem since.
Take the following with a large grain of salt, because I'm no mechanical engineer or armourer:
One thing to remember is that the CX4 is a straight blowback design. The breech block is not locked or delayed on firing, so there's not so many pieces that have to take the recoil forces for a few milliseconds until the chamber pressure decreases. That's in part why the fired cases come out dirty as hell, I think: the chamber is machined with relatively loose tolerances to help with smooth extraction.
The extractor (#28) and ejector (#29) are metal, only the hammer (#42) is a hard polymer and stands in the way of the recoiling bolt. There's possibly some flex in the recoil spring guide (#20) when the bolt moves back and forth, I suppose. I could see those parts having a shortened life expectancy from using hot ammo, but none of them have been reported broken yet AFAIK. The spring guide assy is about US$32, the hammer US$26 at Brownell's. The slides in that guide the bolt movement are polymer, but the movement is linear,just friction over them. They're not taking the recoil forces so those don't worry me.
This being said, there have been a few reports of cracked trigger housings (#33) in some Cx4 around 2014, nothing before then and nothing after that time, to it looks like the factory had a bad batch of housings go through QC and fixed that problem since.
