Bersa Thunder problem / question.

[birddog]

Ok, folks, particularly Stephen Camp and Horge, I have a potential problem and question for you.

I bought my Bersa Thunder a while back and have put several hundred rounds through it. Six hundred, to be exact. I love it. Shoots great, carries great, handles great. It's become my fulltime CCW. Also, there have been no FTF, just one FTE, but only after 60 rounds at the range and it was DIRTY. Thanks, Wolf Ammo.

Now, to the question.

On my last field stripping I noticed small gouge marks on the slide. The right side, if you were holding the gun in shooting position. There are two small gouges, and a scratch where the slide meets the rail.

To answer the obvious, no, there are no burrs or defects to be found on the rail. It's possible that a piece of debris worked its way in between the rail and the slide and just made a one-time pass through.

I am not overly concerned, but wondered if anyone has seen similar wear-marks (not that that's what they are) on their Bersa Thunder .380s. I'll attach a pic below.

Thanks for your input!

Joel

 

[Spot77]

I have almost the same exact markings on my Bersa.

I have over 1,300 rounds through it; maybe even closer to 1500.

Not a single failure, other than when I tried shooting one-handed with my left hand (I'm right handed; I just wanted to do a little cross hand training). Had one FTE left handed.

Those marks might have something to do with the trigger.

 

[rbernie]

Looks like peening marks from a disconnector-type lockwork component...

 

[alwims]

I just pulled mine apart and I've got an almost exact same mark on mine. Can't really tell what would be causing it but it doesn't look like something, I personally, am too concerned with. Pull the slide off my Firestorm and it's got a simular mark on it also.

 

[horge]

Don't sweat it too much
This is the second time this issue has been brought up the past couple of days. The gouge is superficial and is the result of the disconnector nub dragging along the softer metal of the (I suspect) investment-cast slide.

I don't think BERSA has its investment casting game down yet, not like Ruger and Armscor do, but anyway, the gouge is superficial and won't affect function (which i'll explain in a bit). IMHO the affected portion of the slide will tend to work-harden over time, slowing the wear considerably. most long term owners of BERSA's see the wearing settle down around the 2,500 round mark. Based on regular photo-documentation, mine has slowed down already at 900 rounds --remember that mag-in dry-fire cycling counts just as much as live-fire for this issue, so it's really mag-in slide cycles we should be counting.

Function:
The trigger bar is also called the 'disconnector' in Bersa literature. This is by virtue of its abilty to disconnect the trigger from the fire control mechanism, depending on whether the trigger bar is lying a bit up (connected) or a bit down (disconnected). The trigger bar has an upward protrusion near its rear, shaped like part of an upright disc, which I like to call the disconnector nub.

The trigger bar itself is, by springloaded restraint of the magazine disconnect safety strap, normally down (disconnected). The trigger only works if a magazine is present, forcing the safety strap up, and allowing the trigger bar to rise (connected).

But there's another thing preventing the trigger bar from rising even with a mag in place, and that's the underside lip of the slide. There's a shallow slot or trough at the rearward end of the gouge you all have noted. You can see this long slot in the photo posted atop this thread. I like to call it the disconnector slot. It neatly accepts the upward protrusion I earlier called the disconnector nub. Unless the slot is in position to accept the nub and allow the trigger bar to rise, then triggerpull = nothing happens.

The point to all this is so the trigger won't work unless the disconnector nub is in the slot, and this only happens when the slide is in the proper, forward-most position. Proper battery and all that. Of course, as the slide cycles, that trigger bar nub is going to drag back and forth along the slide's underside lip, as the nub pops in and out of the slot, enabling and disabling the trigger in split-second cycles.

Lemme show you...
With a mag in, the trigger bar allowed to rise, and its disc-like nub shows up right by the rails
(that means the disclike nub will contact the slide lip).

If the nub's not in the slide's disconnector slot (meaning, the the pistol's out of battery), the slide lip will keep this nub and the whole trigger bar down and the trigger safely disconnected/disabled.


With the mag out, the trigger bar goes down and its nub drops nearly out of sight

At the magwell lip, you can find the lower end of the magazine disconnect strap.

If you push this strap-end up into the grip (or --hehe- just slap a mag in) and give the trigger a very light pull or tap, the trigger bar rises and you'll see pretty much what's in the first photo I provided.

----

Again, from all reports, the "gouging" settles down, and I suspect it is because the affected portion of the slide is technically being hammer-worked into hardness by the banging contact with the disconnector nub. I consider it part of the general phenomenon we call break-in. For this superficial "gouge" to affect function, it would have to approach the depth of the disconnector slot where it starts.... not likely.

You can help things by keeping the slot and slide-lip lubed and clean. Ditto the disconnector nub.


hth


horgy porgy

 

[birddog]

Horge, thanks

I appreciate the information, and the photos. Excellent explanation.

Thanks again.
Joel

 

[Vitamin G]

I had the same marks on mine before I traded it.
Sometimes I miss it, then sometimes I rememeber it was .380, and I wasn't personally comfortable with that.
Shame, I liked it alot.

 

[alwims]

Dang horge, ya beat me to it. That's what I was going to say but I couldn't find the right words or my camera.

 

[horge]

Alan, pfffhhh...

All yuor explanation are belong to us.

 

[P95Carry]

Kudos Horge .. nicely and efficiently covered .. another valuable piece for the archives.

 

[alwims]

Come on horge, don't tell everybody where I get my smarts. Geez, I'm just posting these meaningless posts so I can get 'Senior Member' under my name like you guys. Disclaimer; for all you serious folks I's just kidin'.

 

[hksw]

An excellent explanation horge.

The cause for the indentation is that when the disconnect extension of the trigger bar gets quickly pushed down (to disengage the sear) by the front of the curve of the disconnect notch under recoil, the extension springs back up into the bottom of the rearward traveling slide at roughly the same place hammering a small divot into the surface. The reason you see a smaller divot a little farther down is that the extension bounces back down a little after hitting the bottom of the slide at the first divot and springs backup at roughly the same smaller second divot spot. From there, the extension mostly drags under the bottom the of the slide the rest of the way until the slide moves forward again. You'll notice that there are faint drag marks between the notch and the first divot as well as between the first and second divot. This is mostly due to manually cycling the slide (i.e., not under recoil from a round fired).

This is a normal feature for most semis witha disconnect notch machined into the slide. Since the notch on your Bersa is relativelycentered on the slide rail width, the hammering the slide sees shouldn't be too big of an issue. There are guns out there, like an early model Taurus PT908 I had, where the notch was machined at one side of the slide rail. The front portion of the notch which pushes against the disconnect (like the front portion of the notchon your gun) eventually got hammered to the point of hindering slide travel due to the burr that developed. As mentioned, how deep or serious the deformation is depends on the quality of the steel and the strength of the disconnect spring. . The sheet metal slide on my shooter P226 shows very little wear and almost an imperseptible divot looking mostly like a simple drag mark from the notch. (The disconnect springis strong enough to prevent the disconnectextension from bouncing around.)

 

[horge]

Ron,

Thanks for describing the tendency for the "nub" to hop and skip after it pops out of the "slot" in a live-fire cycle, producing the impact dimples along the slide lip --atop the dragging rut I had focused on.

I think that if Bersa could take notes from Ruger and Armscor on how to make properly-hardened investment castings, they could afford a stronger disconnector spring that could damp out the hop-and-skip. As it is, a stronger spring might mean a deeper (albeit more even) rut in the slide lip, and greater erosion of the forward end of the "slot".

Of course, if the slide were a harder steel to begin with, the hop-and-skip wouldn't dent it so much, and no one might bother to bring any of this up for discussion!