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View Full Version : Magazine scratching casings - safe to fire?



K_W
11-03-2014, 11:30 PM
While checking over my wife's CM9, I noticed that the mag lips are leaving scratches in the casings deep enough to catch a fingernail.

http://i1294.photobucket.com/albums/b606/KWA900/DSCN5785_zpscec00529.jpg

Should I be concerned about chamber pressures causing a rupture when fired?

This gun has fired 100's of trouble free rounds, but I want to be sure, her life is entrusted to this gun.

wyntrout
11-04-2014, 04:32 AM
If it's caused by the magazine lips, you can lightly sand... 300-400 grit is what I use... to get rid of the sharp edges. I like to do that with new magazines, along with removing the grease from inside the tube and lightly oiling the spring, I check for any burrs, roughness, or sharp edges with the sandpaper. Don't alter the square edges of the retention notch, though.

Wynn :)

Buzzard45
11-04-2014, 08:01 AM
As wynn says, clean up those mag lips. As for the scratched casings, the one pictured looks iffy. by that i mean the side of the casing is fully supported in the chamber,so if it chambers it would be ok, if it splits it might not eject. If however, the scratch goes down into the beveled area, that area is not supported and could cause a boom instead of a bang. If in doubt, get a bullet puller and de-cap , dump the powder in a cup of water to neutralize, as for the primer, there`s a way to neutralize them by soaking , but i can`t remember what that is. personally, i would load the empty case and fire off the primer then trash the casings .

marshal kane
11-04-2014, 09:21 AM
I've posted twice on this problem concerning sharp interior magazine feed lips. If you do nothing, in time and lots of rounds, those burs left on the magazine lips will eventually wear down but my solution is to de-bur using a steel rod e.g. the shank of a drill bit. It helps if you depress the magazine follower then put something through the magazine's inspection hole e.g. straightened paper clip to keep the follower away from the feed lips then rub the burs off with a drill bit. Leaving those burs on the feed lips can actually cause failure to feed problems as the force needed for the slide to strip the round out of the magazine can slow the slide down to where the round may fail chamber. Before the de-burring, place a spent case in the magazine and strip it off with your thumb noting how much pressure it takes to strip the case. After de-burring, repeat the test. The case should strip off the magazine like a greased pig.

As to whether it's safe to fire the rounds after they've been scored, it's likely safe since the brass is thickest at the base and the round is fully supported by the chamber. I say "likely" because there are no absolutes when you have this kind of condition. It's a judgement call but if it were me, I'd fire the rounds then leave the cases on the ground.

jocko
11-04-2014, 10:23 AM
smooth the lips and shoot 5th fokker like u stole it. Just sayin

muggsy
11-04-2014, 06:01 PM
I doubt seriously that firing that round would cause any problems. The deepest part of the scratch occurs in the strongest area of the case, the web, and above that it's fully supported by the barrel chamber. I would smooth up the feed lips of the magazine to preclude any future occurrences.

CJB
11-04-2014, 08:19 PM
That happens. Seen it on Colt .45 Auto mags, S&W mags, Browning HP mags.... ya know... they leave a rough edge or burr, that'll happen cuz the steel is much harder than the brass or gilding metal.

SmokyT
11-05-2014, 08:38 PM
I use #1000 wet/dry sandpaper to smooth the rough edges of magazine lips. None of my magazines scratches cartridges like that or cut my thumb any more.

garyb
11-06-2014, 07:21 AM
Simply smooth out the lips with some very fine wet/dry sandpaper to get rid of the edges. Clean up the inside of the mag and spring to get out all the grease and crap...., then wax the inside of the mag and spring with paste wax or frog lube (follow the directions). Use a soft clean cloth to buff/wipe out the wax and you will be good to go. Not that big an issue.

MBSL500
11-06-2014, 10:13 AM
Simply smooth out the lips with some very fine wet/dry sandpaper to get rid of the edges. Clean up the inside of the mag and spring to get out all the grease and crap...., then wax the inside of the mag and spring with paste wax or frog lube (follow the directions). Use a soft clean cloth to buff/wipe out the wax and you will be good to go. Not that big an issue.

Why should this be necessary?

Bawanna
11-06-2014, 10:33 AM
It really isn't necessary. Its just making things better and smoother.

Polishing the feed lips generally isn't necessary either, just shooting will smooth them in time but polishing just makes it better.

As CJB said, I've seen it in many different brands. Stamped out mag tubes, some get out a little bit rough.

A two minute fix and all is right with the world.

mr surveyor
11-06-2014, 06:03 PM
Non-issue for all but reloaders .... then they gotta be analretentive

garyb
11-07-2014, 07:01 AM
Why should this be necessary?

It isn't really necessary if you don't have any problems with case scratches or you don't want to get rid of the case scratches. Just offering a suggestion to solve the ops problem. It will work....give it a try.

marshal kane
11-07-2014, 07:42 AM
Non-issue for all but reloaders .... then they gotta be analretentive

An "anal" reloader wants to turn out reloads that duplicate factory ammunition in both performance and appearance. Some of us reloaders are very picky.



. . .. Stamped out mag tubes, some get out a little bit rough.

A two minute fix and all is right with the world.

Ditto that! In the area of magazine feed lips, that roughness can slow down a slide trying to strip a round out of the magazine enough to cause a failure to chamber. That was my main problem when I was breaking in my Khar.

muggsy
11-07-2014, 08:45 PM
Why should this be necessary?

It shouldn't be, but in this case it is. (No pun intended.)

muggsy
11-07-2014, 08:47 PM
I scratch my initials into every case that I intend to reload. It avoids fist fights at the range. :)

jocko
11-08-2014, 06:56 AM
I scratch my initials into every case that I intend to reload. It avoids fist fights at the range. :) who in the hell would want anyt cases that u ever owned. u shold put ur phone number on there so the cops can find u faster. Just sayin.

CJB
11-08-2014, 07:42 AM
Non-issue for all but reloaders .... then they gotta be analretentive

You mean like putting one's initials on each piece of brass to avoid fights over it at the range?

muggsy
11-08-2014, 08:16 AM
I shoot in a tough neighborhood. What can I say? :)