what does "peening" mean?

[AcceptableUserName]

can someone explain the term and event to me? how to avoid and diagnose it, etc

 

[atblis]

It's a deformation of a metal objected through repeated impacts. It can also be an intentional process with benefits. When brought up in a firearms context, it is generally a bad thing, a form of unacceptable wear.

 

[The Lone Haranguer]

Stippling, as often seen done to grip frame frontstraps, is an example of peening of the good kind. Rounding off and mashing over of barrel locking lugs due to inferior materials or fitting is an example of the bad kind.

 

[sig228]

check out the photos near the bottom of this link:

http://www.ktog.org/cgi-bin/yabb2/YaBB.pl?num=1195228428

 

[rcmodel]

Ball-Peen Hammer:
The original function of the ball-peen hammer was to "peen" rivets by smashing the end out to make it hold a part in place.
This is good.

If your gun is peening metal into a different shape?
This is bad.

rc

 

[highorder]

It's a deformation of a metal objected through repeated impacts. It can also be an intentional process with benefits. When brought up in a firearms context, it is generally a bad thing, a form of unacceptable wear.

Couldn't have said it better myself.

 

[MachIVshooter]

It's a deformation of a metal objected through repeated impacts. It can also be an intentional process with benefits. When brought up in a firearms context, it is generally a bad thing, a form of unacceptable wear.

Exactly. One might peen the bottom of a screw or bolt in a hole to keep it from backing out, or peen the material around a pin for the same reason. Basically, when done intentionally, it is used to make fitted parts a more permanent arrangement, without going to the extreme of fusing (welding). On guns, many times the extractor pin is peened in place so that it cannot work it's way out and be lost or damage internal parts if it fell through to the bottom.

But the negative side atblis is talking about would be such things as the slide or barrel peening the frame. I had such a problem with my Witness Limited 10mm at first. In some cases, it is self-limiting. In others, it can cause serious and irrepairable damage to a gun.

Where the red arrows are pointing is where the barrel was hitting the frame under recoil with full power loads, smashing the metal inwards. In this case, it was self limiting. Once the surface enlarged from the peening, it became sufficient to bear the impacts without further deformation.

 

[rocinante]

In another context peening is done to destroy markings of a military rifle. The Russians routinely peened out any nazi markings when they rearsenaled captured german weapons. Most japanese rifles had the royal mum erased but as a good will gesture not to shame the emperor's symbol. Generally milsurp with their marking unaltered sell for a premium.

 

[atblis]

Here's another benfeicial form of peening that you may see in the firearms world.
http://en.wikipedia.org/wiki/Shot_peening

 

[Peter M. Eick]

Here is peening and what it does over time.

 

[atblis]

What gun is that? Something Spanish?

 

[RedAlert]

Racing automobiles often use peening on some engine components like the crankshaft, rods and valves.

The peening process removes stress risers which are a source of cracking. This is a process to improve the longevity of the components under race stress.

I would imagine a similar process could improve the frame or slide of a semi-auto pistol.

 

[KevinR]

Peening - On our 10 ft screws in our plastic extruders, we will sometimes peen the screws to take out slight binds. The idea is to smash the metal in one spot to cause it to expand and make that side longer

 

[Peter M. Eick]

The Pistol is a COLT government 380.

Not any sort of spanish copy.