Can a misfeeding Ruger Mark II magazine be revived?

spacecoast · December 30, 2012, 06:22 PM

I have a total of four magazines for my Ruger MKII512. A couple of years ago I discovered that one of them consistently misfeeds one or two rounds per mag, and now another one does as well. I have cleaned them inside and out (with disassembly) but the problem persists. The remaining two magazines function fine.

Does anyone know the common cause of feeding issues and if/how the magazine might be tweaked to correct this? When a misfeed occurs, the old brass usually fails to eject and gets stuck behind the next round, which gets partway into the chamber. Holding the bolt back, you can usually pluck out the old brass and then let the bolt go to seat the next round.

ritepath · December 30, 2012, 07:19 PM

A friend of mine has a 22/45 mag that he dropped once, it's never fed right since. He's showed it to everyone to find any damage but it's just not there, still it won't feed properly for crap.

Thanks for making me aware that I only have one mag for my MKII.

Oswald · December 30, 2012, 07:54 PM

Try rounding off the sharp inner edges of the magazine.(open area where cartridge is visible). Use small file or Dremel type tool with cutoff disc or small grinding wheel. Simulate front opening / grind a smaller radius. This operation worked wonders with my MK II's. 24 magazines.

Oswald

drail · December 30, 2012, 10:38 PM

Are the rounds that misfeed the last 2 or is it just random? If it is the last several rounds you need a new spring. On the rounds that fail to eject, are they getting hooked by the extractor and being pulled out and being struck by the next round out of the mag?

dahermit · December 30, 2012, 10:53 PM

Quote:

When a misfeed occurs, the old brass usually fails to eject and gets stuck behind the next round,

If a case is failing to eject, there may be some issue with the extractor. The first thing to do is NOT to start filing or sanding on the magazine lips because if they are not the problem, they soon will be. If you do not want to take it to a gunsmith but investigate the cause yourself. Try to slip a fired case under the extractor and get the empty case back into the chamber. Put one round into the affected magazine, insert it into the gun. Pull back slowly on the slide and watch what happens in an attempt to see why the empty case is not being extracted and thrown clear by the ejector. Test, experiment, but cut no metal until you are very sure what is causing the problem. Nevertheless, it sounds like more of an ejection problem than a magazine problem.
Examine both the extractor and its spring (.22's are very dirty, things get sticky very quickly), and the ejector.
One other thing to try, is a new box of cartridges...I have an old brick of .22's that fire, but do not have the required power/force for the empties to clear the chamber of my Buckmark.

spacecoast · December 31, 2012, 07:33 AM

Quote:

Are the rounds that misfeed the last 2 or is it just random? If it is the last several rounds you need a new spring. On the rounds that fail to eject, are they getting hooked by the extractor and being pulled out and being struck by the next round out of the mag?

It's just random, sometimes it's well down in the mag, sometimes not. The rounds that fail to eject are getting hooked and pulled but are not exiting before getting stuck between the tail of the next round and the far-side wall of the receiver (away from the exit port).

Quote:

Put one round into the affected magazine, insert it into the gun. Pull back slowly on the slide and watch what happens in an attempt to see why the empty case is not being extracted and thrown clear by the ejector. Test, experiment, but cut no metal until you are very sure what is causing the problem. Nevertheless, it sounds like more of an ejection problem than a magazine problem.

Thanks, I do need to run rounds through manually to see if I can recreate the problem. Removing the bolt and disassembling/cleaning the extractor as much as possible is also a good idea, although I am still pretty sure that it's magazine-related as it only happens with the same two magazines.

Sport45 · December 31, 2012, 09:49 AM

Be very aware of muzzle direction and trigger discipline when performing those tests. I suggest doing this outside.

blchandl2 · December 31, 2012, 09:58 AM

What kind of ammo are you using and what is the shape of the bullet? I have noticed problems with truncated cone bullets on my 22/45.

Stevie-Ray · December 31, 2012, 02:08 PM

I have an old Mark I mag that has always been problematic also. The original one has never failed and neither has a cheap Ramline Hi-cap with "constant-force spring." I could never figure it out either.

Rainbow Demon · December 31, 2012, 02:42 PM

Don't know if it applies here, but according to articles I've read on designs for .22 RF magazines, and why many older designs were never reliable, stated that retention at the forwards portion of the feed lips was a key factor.
Some more reliable .22 mag lips have small nibs or indentations near the front.

Been awhile since I've owned a Ruger autoloader, mine was never particularly accurate so I sold it off long ago. I remember mine as being extremely reliable with the original mag and a 12 round replacement. It would even feed .22 Shorts flawlessly so long as I put only six in the magazine, and tapped the mag to shift the rounds towards the front.

The Rugeris a great design, but just never felt right in my hand, far too bulky for a .22.

spacecoast · December 31, 2012, 08:20 PM

Quote:

What kind of ammo are you using and what is the shape of the bullet?

I use two kinds - Federal bulk ammo (copper hollowpoint) and Federal target match, which is lead round nose solid.

Quote:

Be very aware of muzzle direction and trigger discipline when performing those tests. I suggest doing this outside.

Will do.

Andrewh · December 31, 2012, 11:27 PM

one last thing to try.
since you took them apart already.

swap the guts of a known good one with a known bad one and see if you can replicate the problem with either mag.

if it follows the internals, then swap the follower only.

the part it follows or stays with is your problem.

you may see if ruger will fix it.

December 30, 2012, 06:22 PM	#1
spacecoast Senior Member Join Date: October 14, 2009 Location: Sunshine and Keystone States Posts: 4,461	Can a misfeeding Ruger Mark II magazine be revived? I have a total of four magazines for my Ruger MKII512. A couple of years ago I discovered that one of them consistently misfeeds one or two rounds per mag, and now another one does as well. I have cleaned them inside and out (with disassembly) but the problem persists. The remaining two magazines function fine. Does anyone know the common cause of feeding issues and if/how the magazine might be tweaked to correct this? When a misfeed occurs, the old brass usually fails to eject and gets stuck behind the next round, which gets partway into the chamber. Holding the bolt back, you can usually pluck out the old brass and then let the bolt go to seat the next round. Last edited by spacecoast; December 30, 2012 at 06:51 PM.

December 30, 2012, 07:19 PM	#2
ritepath Senior Member Join Date: February 22, 2009 Location: Virginia Posts: 1,419	A friend of mine has a 22/45 mag that he dropped once, it's never fed right since. He's showed it to everyone to find any damage but it's just not there, still it won't feed properly for crap. Thanks for making me aware that I only have one mag for my MKII. __________________ There's only one...

December 30, 2012, 07:54 PM	#3
Oswald Junior Member Join Date: March 18, 2012 Posts: 12	MK II Mag feed problem Try rounding off the sharp inner edges of the magazine.(open area where cartridge is visible). Use small file or Dremel type tool with cutoff disc or small grinding wheel. Simulate front opening / grind a smaller radius. This operation worked wonders with my MK II's. 24 magazines. Oswald

December 31, 2012, 09:49 AM	#7
Sport45 Senior Member Join Date: May 25, 1999 Location: Too close to Houston Posts: 4,196	Be very aware of muzzle direction and trigger discipline when performing those tests. I suggest doing this outside. __________________ Proud member of the NRA and Texas State Rifle Association. Registered and active voter.

December 31, 2012, 02:08 PM	#9
Stevie-Ray Senior Member Join Date: May 22, 2007 Location: The shores of Lake Huron Posts: 4,783	I have an old Mark I mag that has always been problematic also. The original one has never failed and neither has a cheap Ramline Hi-cap with "constant-force spring." I could never figure it out either. __________________ Stevie-Ray Join the NRA/ILA I am the weapon; my gun is a tool. It's regrettable that with some people those descriptors are reversed.

December 30, 2012, 10:38 PM	#4
drail Junior member Join Date: February 2, 2008 Posts: 3,150	Are the rounds that misfeed the last 2 or is it just random? If it is the last several rounds you need a new spring. On the rounds that fail to eject, are they getting hooked by the extractor and being pulled out and being struck by the next round out of the mag?

December 31, 2012, 09:58 AM	#8
blchandl2 Senior Member Join Date: November 1, 2008 Location: TN Posts: 525	What kind of ammo are you using and what is the shape of the bullet? I have noticed problems with truncated cone bullets on my 22/45.

December 31, 2012, 02:42 PM	#10
Rainbow Demon Senior Member Join Date: September 27, 2012 Posts: 397	Don't know if it applies here, but according to articles I've read on designs for .22 RF magazines, and why many older designs were never reliable, stated that retention at the forwards portion of the feed lips was a key factor. Some more reliable .22 mag lips have small nibs or indentations near the front. Been awhile since I've owned a Ruger autoloader, mine was never particularly accurate so I sold it off long ago. I remember mine as being extremely reliable with the original mag and a 12 round replacement. It would even feed .22 Shorts flawlessly so long as I put only six in the magazine, and tapped the mag to shift the rounds towards the front. The Rugeris a great design, but just never felt right in my hand, far too bulky for a .22.

December 31, 2012, 11:27 PM	#12
Andrewh Senior Member Join Date: July 7, 1999 Posts: 966	one last thing to try. since you took them apart already. swap the guts of a known good one with a known bad one and see if you can replicate the problem with either mag. if it follows the internals, then swap the follower only. the part it follows or stays with is your problem. you may see if ruger will fix it.