PX4 barrel is binding and holding slide out of battery… I think

[JackNeat]

I have a PX4 purchased used. Was is very good condition and no visible issues. Put around 700 rounds down range since obtaining it.

The last trip to the range after every round the slide would stick to the rear past even where the slide lock would engage. Had to tap it to get it back in battery, after about 5 rounds it was clear something was wrong.

I was also able to duplicate that condition by hand with no magazine and no ammo in chamber.

I removed the barrel and placed the recoil spring in the frame and put the slide on. Cycles fine to rear and does not show any signs of binding. Once the barrel is installed is when this condition happens consistently.

I have to assume something worked it way in there and caused this issue? Not sure what to do right now except take it out of my EDC until figured out.

Some images taken last night.. does anyone see what might confirm excessive wear? I honestly haven’t closely inspected the barrel previously that I can say yes or no.

The image of the barrel attach#98183 seems to show possible gouge in the groove?

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[JTQ]

It may be some other problem, but my first troubleshooting step would be to make sure the gun was lubed properly.

[Squib308]

PX4 Storm Tracker

[medmo]

First thought, is recoil spring/guide installed backwards? Not sure if it is physically possible to re-assemble with it backwards but that's my first thought.

[revchuck38]

It may be some other problem, but my first troubleshooting step would be to make sure the gun was lubed properly.

+1. I've got three PX4s and none of them have done this. I have noticed that they like to be run relatively wet. I lube them about every 500 rounds or so.

[JTQ]

First thought, is recoil spring/guide installed backwards? Not sure if it is physically possible to re-assemble with it backwards but that's my first thought.
I don't think that's possible.

[medmo]

I don't think that's possible.

I was leaning towards most likely not possible but then again I have some impressive personal accomplishments on my record where I have made the impossible possible when mistakenly doing something backwards. I'll check on my PX4s next change I get.

[gringop]

Not familiar with the PX4, in a Glock or other non-rotating barrel I would suspect a barrel bulge. Any recent high pressure rounds or a possible undetected squib with another round fired while the squib was in the barrel? Are you shooting reloads?

With just the barrel in the slide can you run the barrel forward to where it sticks then mark it and check for bulges, burrs or other reasons that it won't continue through the bushing in the slide?

Gringop

[PX4 Storm Tracker]

I have a PX4 purchased used. Was is very good condition and no visible issues. Put around 700 rounds down range since obtaining it.

The last trip to the range after every round the slide would stick to the rear past even where the slide lock would engage. Had to tap it to get it back in battery, after about 5 rounds it was clear something was wrong.

I was also able to duplicate that condition by hand with no magazine and no ammo in chamber.

I removed the barrel and placed the recoil spring in the frame and put the slide on. Cycles fine to rear and does not show any signs of binding. Once the barrel is installed is when this condition happens consistently.

I have to assume something worked it way in there and caused this issue? Not sure what to do right now except take it out of my EDC until figured out.

Some images taken last night.. does anyone see what might confirm excessive wear? I honestly haven’t closely inspected the barrel previously that I can say yes or no.

The image of the barrel attach#98183 seems to show possible gouge in the groove?

Your cam and barrel look fine and unmarred.

Firstly, I would suggest that you always make sure to put a ring of grease around the cam lug.

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For more suggestions on lubrication, check out this map:https://pistol-forum.com/showthread.php?21539-Beretta-PX4-full-size/page3 post 27

The guide rod assembly cannot be put in backwards, as the guide rod is too long if the rear point (that locks it into the frame) is out of place.


So, the rotating barrel does more than rotate. There is a straight channel at the rear end of the barrel's cam track where it locks in for more pressure relieving delay, even before rotating. It should not be overlooked for lubrication. https://pistol-forum.com/showthread.php?29665-Beretta-PX4-Storm-Parts-What-does-each-part-do-and-how/page4 post 37

It is possible that the pistol was stored with the slide back or some other thing made the rebound spring weak or old. A new guide rod assembly is possibly needed. It seems less likely, as it ran for 700 rounds. They don't poop out suddenly.

I would try wiping down all parts and putting the ring of grease and grease on the sides of the barrel's cam track first.

Was the ammo exceptionally hot?

[JackNeat]

Thanks for the info! I have not applied any special attention to the cam lug as just suggested. This is the first time hearing about that so thank you. I have just run the pistol wet - ballistol as cleaner and lube.

The recoil spring was always installed properly. I did order and just received a new recoil spring assembly from Baretta as I was thinking it might be a good idea to have it on hand.

The ammo I have run is 124gr Fiocchi. The majority of that 700 though was white box Federal 115gr which was shot at an all day class a few months ago.

I will go over those links you posted to familiarize myself with the recommendations and I'll definitely start to apply some grease to the lug and barrel groove as suggested.

Glad to hear that nobody saw any odd or excessive wear... Hope to report back that the wipe down and follow up lubrication and some grease applied as needed is the fix.

[AdioSS]

Yep, in the rotating barrel Berettas it is good practice to run grease around the cam block lug instead of oil. Plenty of friction there. That’s why the SD block is DLC coated.

[medmo]

So I tried it. Even I couldn't assemble the pistol with the recoil spring/guide backwards. Tried it on Compact and Full size. How hard did you have to tap it forward to get the slide to close? I understand the importance of lube and also use grease on the lug also. You were able to repeat the failure by hand cycling? When the slide is all the way back the bottom of the slide contacts/depresses the hammer. The slide moving rearward contacts the hammer, cocks it and remains in contact. Notice anything irregular when repeatedly thumb cocking? Potentially the spring is binding or sometimes binding on the hammer stirrup. Maybe try to recreate the error by hand cycling with the hammer spring removed. If you can recreate the locked up condition, can you depress the hammer or is it fixed and remains in contact with the slide?

[gato naranja]

Yep, in the rotating barrel Berettas it is good practice to run grease around the cam block lug instead of oil. Plenty of friction there. That’s why the SD block is DLC coated.

This.

Not to start a lube war, but I use Slip 2000 EWL overall and Slip 2000 EWG on the camming surfaces of PX4s; it didn't start out that way, but that is how it ended up.

[JackNeat]

So I tried it. Even I couldn't assemble the pistol with the recoil spring/guide backwards. Tried it on Compact and Full size. How hard did you have to tap it forward to get the slide to close? I understand the importance of lube and also use grease on the lug also. You were able to repeat the failure by hand cycling? When the slide is all the way back the bottom of the slide contacts/depresses the hammer. The slide moving rearward contacts the hammer, cocks it and remains in contact. Notice anything irregular when repeatedly thumb cocking? Potentially the spring is binding or sometimes binding on the hammer stirrup. Maybe try to recreate the error by hand cycling with the hammer spring removed. If you can recreate the locked up condition, can you depress the hammer or is it fixed and remains in contact with the slide?

probably about the same type of tap you would give a magazine to properly seat it.

On that day at the range I could replicate the slide binding to the rear but I did have to rack it hard. Nothing odd or different feeling about the hammer or cocking the hammer.

After reading through some of the posts made by Storm Tracker (and joining the Facebook owners group) I am gaining a much better understanding of the PX4... Until a few days ago... I basically just knew how to field strip the pistol but didn't really delve any deeper into understanding it. Looking forward to digging in deeper.

Just came home with some Hoppes Gun Grease and a large bottle of Hoppes 9. Going to clean the pistol up as best I can without going past field stripping (I am still not super comfortable breaking it down further but I am going to make that a goal). I'll follow the lube schedule created by Storm Tracker and see if that eliminates the issue I'm currently having. The PX4 is one of 2 pistols I own. The other is a Girsan Regard (92 clone). I need to get an IWB holster for that just in case I run into trouble breaking the PX4 down.. I want to make sure I have a backup for carry.