PM40 mag scratches cases

a.squibload · #1 03-05-2010, 12:11 AM

Kinda new here, searched for this phenomenon, didn't find it posted yet.

My PM40 is kinda new, July this year, maybe 500 rounds. All my magazines
(5- and 6-rounds) scratch the cases enough when feeding that I can feel the scratches. Almost like "scoring". Caused by sharp inside edges on feed lips. Wondering if it could weaken the brass? I tried a ceramic sharpening stick a little bit on one mag, tried to break the edge. Don't want to overdo it and change feed characteristics, but maybe a file would do a better job?

I intend to reload as soon as I unbury my work table, was a revolver guy 'til I found this Kahr! Meprolight sights, Smartcarry. Appreciate opinions on this...A.

jocko · #2 03-05-2010, 06:04 AM

not sure your gonna hurt anything by trying it. I with every new magazine take some 600+ grip auto sand paper and roll it up and polish the under side of the mag feed lips. Again your not taking off any metal, just smoothing things out some. Not sure the ceramic stone is the right thing, to use, although I have never used one, so I am just guessing. I don't think either those scratches will harm reloading any

Frankhenrylee · #3 03-05-2010, 10:03 AM

I like to argue with Jocko so here I go. Its not really an argument but something to add to it. You might consider starting with 600 and working your way up to 1000. I build and work on all sorts of different things and whenever I want to paint something and get a nice smooth finish 600 is just to rough. He loves it when I disagree with him.

jocko · #4 03-05-2010, 10:09 AM

Quote:

Originally Posted by Frankhenrylee

I like to argue with Jocko so here I go. Its not really an argument but something to add to it. You might consider starting with 600 and working your way up to 1000. I build and work on all sorts of different things and whenever I want to paint something and get a nice smooth finish 600 is just to rough. He loves it when I disagree with him.

because your right. Now for me at age 66, I use the 600+ grit paper BECAUSE I don't have the time to do the same thing with 1000 grit paper. I would tend to agree with the painting part but I didn't know the fella was going to paint his brass casing

Bawanna · #5 03-05-2010, 02:29 PM

Just a SWAG here but I doubt the scoring will effect your reloading in a handgun cartridge. I would discourage the painting step but then again I haven't tried that approach.
Just to be the third disagreer here, you can't really knock off a sharp edge without removing metal, that's ok, you just don't want to remove much or change the overall angle. I firmly believe that any polishing (not removing metal) beyond 600 grit would be a wasted effort better spent on your queens fingernails.
Not picking a fight here although I'd probably feel better after a good fisticuff, but as Mr. Jocko mentioned the clock is ticking.

a.squibload · #6 03-05-2010, 11:29 PM

Thanks for replies. I just came from my 4WD club meeting, after which we usually sit around nursing a beer and talking about guns. They tend to agree with you guys, except nobody thought about painting the brass so we didn't talk about that. I suppose the really hot loads could be "hunter orange". Haven't reloaded 40s&w yet, have read about high pressure, "glocked brass",
and unsupported case heads. Didn't want to disappear in a mushroom cloud at the firing range due to my sharp magazine edges. The crock stick seemed to dull the edge a little, maybe that's good enough and I shouldn't be so picky.
Thanks again...A.

wyntrout · #7 03-06-2010, 12:27 AM

All I have is 400 grit and that's faster... shoot, the 200 would be even faster!

I haven't fired up my "Dremel-like" tool lately. That thing came with 200 or so little thingies to play with. The first time I used it was on a DVD from BlockBuster. I was just gonna buff out a little scratch. Dang! Did you know that thing creates a lot of heat and that plastic just discolored and melted. I emailed Blockbuster and they sent me another copy of the same movie.
That 20,000 RPM can create some friction real fast with a buffer wheel and a little polishing paste.

It works better on the feed ramps of these pistols. They don't melt as easily.
Wynn

Bawanna · #8 03-06-2010, 10:48 AM

The dremel tool was a wonderful invention. Sadly many guns and lots of other things have been ruined by overzealous repairmen with a grinding wheel instead of a polishing wheel.
They sure help get the job done when used with discretion.

a.squibload · #9 03-07-2010, 09:54 PM

My dremel is actually HER dremel, she makes jewelry. Sometimes an
angle grinder is just too big. I have learned to keep the wheels (on both)
away from their power cords. And my fingers.

jeep45238 · #10 03-08-2010, 03:53 AM

It won't weaken brass, but it isn't helping anything either.

I shoot the heck out of my mags, the sliding brass polishes the inside of the feedlips as I go