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I polished up the bolt in my Mark III a couple of weeks ago. Used it a bit to let the wear show, and polished those rough spots off again.

And right now, that bolt slides in and out, as smooth as glass. (actually, more like ice on ice). Easier to operate also. (just a bit)

Roybi sells a Stainless Steel (SS) polishing compound, and a kit with some wheels and a couple other compounds. Included are white (fine) red (jewelers rouge) and black ("emory") that is way to rough for what I want.

After using it without polishing it, the whole thing looked a bit rough, as it came straight from the factory. So I polished the whole thing as best I could. I got mostly a mirror finish on the whole thing (everywhere I could get to anyway), using a Dremel and patience.

I started with the SS compound, and then went with the rouge, and finished with the white each time. That puts a near mirror finish on the stainless steel.

Then, after shooting a couple hundred rounds through it, some more rough spots showed up on the bolt. Not many. These are the areas where the bolt makes contact with the receiver.

So I polished those out.

Doing this, would eventually make the bolt perfectly smooth, mated parts. Because it's the high parts that make contact, wear those down and you don't have any "high" spots any more.

So, after polishing those out, I ran a couple hundred rounds though it again today, and there were very few rough spots showing up.

That means I'm getting there.

I also polished the top of the bolt, where the recoil spring (U-Shaped thing) makes contact, and that U-Shaped thing (that contacts the bolt pin).

After doing that, the bolt operation is as smooth as it can be. Maybe one or two more times should do it, no need to do any more.

It will always have some wear on it, but once you get rid of those high spots, and have a nice polish on it, there's nothing to "grind" against anything so it's operation will be smooth.

If anybody is interested, I can post some photo's.

Most of this action would happen normally after a few thousand rounds. But it wouldn't quite as good.

I'd like to see what other parts can be polished, like smoothing out the trigger action, that sort of thing.

Just thought I'd pass that along....

I would be interested in some photos. Sounds like an interesting method of "break-in". I have done something similiar to a few actions, and usually used diamond dust. If you are going to try the "dust" method, take care to be very frugal with it, and only cycle a few times between action checks, and then completely clean the parts and test again. If any of the "dust" is left in the action it can cause very rapid and permanent damage due to "overwearing" the parts. Never wanted to try the dust on any of my auto's though, and am interested in your progress. Keep us posted.

Thanks

JJ

I think I can post some pictures of what I have done. I don't think I can post any that show the wear patterns. It was very slight, and without bluing the whole thing, I don't think it would show up in any photos.

But I think the most results came from polishing the top of the bolt and the U-shaped part of the recoil spring assy.

that U-shaped part was just stamped out, and I noticed some burs on it the first time I cleaned it. I knocked them off with a needle file. But polishing seem to have been the real trick.

I think the sides of the bolt, where the wear shows up, was minor in comparison.

But I'll take some photo's and see what it looks like and post them.

I'd like to polish the inside of the receiver, but just can't do it. but like I said, I think that's secondary to the recoil spring thing.

Yeah, I'd love to have some diamond dust, but that stuff can take off a LOT of metal before you know what's going on. If you've seen them polish diamonds with it, you'd know they use tiny amount of it, and it lasts a good long time too.

Great stuff, but you have to know what you're doing with it. Most of the stuff I have, besides the stuff I just purchased was used in polishing fiber optic cables. Grits measured in microns, that sort of thing, basically glass polish.

But, I'd recommend this action to any stamped part that moves against any other part. Eventually those burrs will wear off, but why wait eh?

A procedure like this has been done before. Check this web page out http://www.100megspop3.com/oldvalkyry/ri.html . This is an intuitive process and it is not unusual for more than one person to come up with a conclusion that performing a specific procedure will smooth out operation of a machine. It is an old procedure that's been out on the web two generations before MKIII.org was created, back when the forum was on Network54.com .

You can polish the inside of the receiver tube with a 1" felt polishing wheel, Dremel Moto Tool or equivalent, a flexible shaft attachment for the moto tool, and polishing compound.

Smoothing up the bolt and receiver manually by polishing just speeds up the natural process of having the metal parts polish each other by contact during the break-in firing period.

Microguy - if you have any problems posting your pictures, let me know. You'll need a picture hosting site like Photobucket.com that has direct linking capability. I have other options if you cannot get them to post.

Hope this helps.

R,
Bullseye

Yes, it only makes sense that metal on metal should be as smooth as possible to work well.

I didn't have much luck with the inside of the receiver. Just seemed pretty tough or something.

I think I have posted a picture here already, maybe not. I've got a website that I load my photo's up to, have several personal photo's up there as well (www.nycestuff.com).

But thanks for the heads up, you don't normally get that.

How about an avatar? I placed one in your profile just as an example. Keep it if you like or make another. I can assist if you have trouble inserting a new avatar into your profile.

R,
Bullseye

I've got one out there that I really like, but hate to use it because it might give me away on another forum (doubt it though).

I'll probably leave that one there for a while anyway.

Thanks