[V10]

When two metal parts are in contact in a high stress/pressure application, the movement of the parts relative to each other can cause metal to be removed from one part and deposited on the other.

This can be seen in some shotguns where the barrel block and receiver are in close proximity and the repeated opening and closing of the action causes metal to "migrate" from one surface to the other.


Prevention? Grease.


Edited to add link to Wiki article on galling.

 

[ms_yuan]

I'm not a metallurgist, but the lay person's definition is metal to metal adhesion (stickiness, or binding) caused by abrasion between two metal surfaces. In the extreme, say, in nuts and bolts, the nut and bolt can seize together, and torquing the nut will cause the bolt to shear.

You can prevent it by not having the metal to metal contact, usually done by putting a film of lubrication, e.g., grease or oil, between the metal parts.

Makes your gun look uglier, too.

I suggest Googling the term, "galling".

 

[Wolfman]

To be a little more specific, the pressure causes the metal to effectively micro-melt and adhere to the other surface. The beginning is so small you can't see it, and once it starts the process continues until you can see it. Grease is the best solution. We experience it in metal to metal rubbing surfaces here frequently. Happens most on materials with similar hardness - eg Rc 55 parts rubbing.

 

[grntitan]

Here is a good example of galling on a BT 99 i got for cheap. Some people do not realize the damage that can be done by not properly lubricating a gun. This gun was less than a year old when i aquired it.

 

[wayneo]

CMD anti-galling gun lube. Works good for keeping choke tubes tight too.

Wayne

 

[pigeon101]

My wifes BT99 Has done the same thing. We always applied grease to area to prevent this. I was told the grease got dirty and caused the galling.
I would think its soft metal/steel that wasn't heat treated correctly while at factory to cause such marks metal wear. What ever the problem is I have only seen this in newly manufactured BT99'S


Jason in PA

 

[grntitan]

Jason--Indeed dirty grease will cause it. You get micro pieces of metal, powder, dirt etc. embedded in the grease from shooting. If not routinely changed, galling will soon follow.

 

[sliverbulletexpress]

Brownings do it often because they come with the forend iron fit way way way too tight and many of the experts at the club will tell you to just keep using it and it will break in. Grease don't help these guns because it just gets squeezed out, oil would be better but would have to be kept up with. A touch or two with a file on the back of the forend lug will prevent it but many won't listen.

 

[Rastoff]

What you often see on guns like the one pictured above, is not always a result of being too tight. It could be caused by not fitting together properly. This is one of the intangible things that makes Perazzi, Krieghoff, Ljutic and others worth the extra money. They rarely have this trouble because they are fit with more precision.

 

[likes-to-shoot]

I think Rastoff has a point. Notice the galling is only on one side. You would think if everything was fitted properly it would show evenly across the whole area.

 

[Frank C]

I have a 30? year old BT 99 that had the same type of Galling....

 

[SMOKEIT]

I think that guns that have a heat treated receiver like Kreighoff are less likely to gall than guns like Perazzi that do not heat treat receivers.......Smokit

 

[221]

I've seen cases where being loose can gall faster than tight....and lubed properly. If its lubed, being tight will not necessarily mean it will gall.

If it is loose grit will migrate into the joint and do what you see in the photo above.

I think a lot of break opens get galled by being played with at the gun shop, before they are sold. Or when they are taken apart and reassembled....

We have all heard the guy trying to bang his gun back together, by rattling the parts against each other. It only takes a tiny ding to cause a major gall job. I saw a BT100 once that looked like a hand grenade went off inside the receiver....it was full of dings and dents from assembly.

I have guns that have to be pushed open and they are not galling.

 

[Voolfie]

Grease can migrate. Grease can also - if left too long and allowed to attract dirt and unburnt powder - become a lapping compound that wears metal rather than preserving it.

The best way to go is: Oil.

Now, this means that you will have to wipe down your barrels & receiver EVERY time you use your gun and then re-apply the oil EVERY time you use your gun. However, you will find that wear is minimized.

The best oil (in my opinion) is CLC Break Free. It cleans and lubricates at the same time. You only need to remember to shake the container before you apply it.

If you use a semi-automatic, I would recommend Remington 'Dry Lube' or a similar lubricating agent. Especially in the smaller gauges, powder fouling is a problem for semi-automatics. If you use oil - and do not disassemble and clean your gun after every couple hundred rounds - residual oil can become a glue-like substance that causes malfunctions rather than preventing them.

And whatever you do...NEVER, EVER...use WD-40 on a gun. It promotes oxidation.

The above is what I've experienced. If you've had a different experience, let's hear about it.

Humbly,

J.F. Wolfington
Philadelphia, Pennsylvania

 

[AEP]

Vactra Way Oil #2 is designed for high pressure applications. It is used on lathes, mills and other machinery all the time.

Despite what others may say. The action of a break-open is much like machinery in regards to close fitting parts. In a lathe the carridge rides on a thin film of oil on top of the bed ways.

Good Stuff.

Andy

 

[221]

Oil is designed to be used in a captive environment, such as a flood or a pressure application. Oil needs to move to lubricate. You use grease when you want it to stay put. Grease is often used in off road applications as a dirt barrier. You don't oil a hitch ball, a backhoe, your car joints. Sealed bearings have grease in them, clean one out and put oil in it and it will burn up.

The theory that oil stays put and grease migrates is backwards.

Grease will not attract dirt any faster than oil will.

BTW Lubriplate works well when used with properly heat treated metals....it ain't worth a crap when used with soft metals, like used in a Browning.

A lot of people shoot, clean and lube their gun then put in the case.....the next time they shoot, they take it out of the case and assemble it and shoot again. Think a while and ask your self what is wrong with that practice.

I clean mine after I shoot, then clean them again and lube them just before I shoot them, the next time.

Guns are extremely high maintenance, break opens have to be kept spotless or they gall.

 

[B-Rod]

All - The galling can also be caused from improper lubrication such as people using WD40 instead of a true lubricant such as Rem-Oil or something of this nature.
The Galling is caused by a foreign object (trapped) between the forearm metal and the surface of the mating metal.
Proper cleaning/lubrication each and every time you use the gun will help prevent this from occuring.

Regards,
Bill Rodriguez
Chief Metallurgical Engineer (Alcoa)

 

[grntitan]

You can use anti-seize on your choke tube threads but i would never use it as a lube on other parts. They make greases designed for that. Its your gun though and treat as you want. The guy i bought the above BT from did not believe in any lube.

 

[W.P.T.]

I use STOS Gold and Clenzoil on all of my guns, no problems with galling and they work nice and smooth as they are made to ... I take the trigger out of my Perazzi about once a month clean it with Clenzoil, blow it out with an air hose and put it back where it belongs lightly lubed ... WPT ... (YAC) ...