22/45 MKIV Feed Problem

[Dirty_J]

Had my first outing with a "new to me" 22/45 MKIV today and had some less than stellar results. 

 

 

1) With a full 10rd mag, it would occasionally send the first round to the top of the chamber and wedge in place. Is there normally a small ledge between the feedramp and the chamber? Looks problematic to me, but thought I'd ask before messing with it. 

 

Tried to sling shot. Tried to use the bolt catch. Problem occured both ways. 

 

2) This same malfunction would sometimes occur a few rounds into the magazine 

 

Tried a variety of ammo. Blazer. Aguila. CCI Standard velocity, Federal and minimags. Copper jacket and lead. Round nose and FMJ. 

 

Some were worse than others, but none perfect. 

 

I could not attribute it to one ammo type or magazine (had 4 to use)

 

Is it normal that the top bullet can wiggle up and down in the magazine? I know with center-fire cartridges this can absolutely cause such feed issues. Not sure if rimfire is different. 

 

3) The gun would also only occasionally lock back when empty. Even with the high velocity stuff. 

 

Is the bolt catch finicky or do you think I'm getting a short stoke? It's doing this even with the 1200+ fps stuff, so if short stroke, there's got to be something going on with the action.  

[outerlimits]

went thru this last year-most likely mag related.  try this with a  mag and see if it does the trick.  i ended up doing all my mags this way.  problem solved.

 

 

[Dirty_J]

Will give it a go. Thanks. 

 

Mod the same for MKIII and MKIV? Think the tubes are the same right? Just different base pad?

[outerlimits]

mds are the same-mine is a MKIV.

[Dirty_J]

Found another site showing how to tune the feedlips for case rim height and angle. 

 

Taking the calipers to 3 brands of ammo I have on hand shows 0.006" variance from smallest to largest. 

 

Hitting the top of the chamber can be due to the bolt skimming across the rim and grabbing the cartridge after the rim. 

 

https://www.wirthweinguns.com/Ruger-MK-Mags.php

[RickT]

I'm going through this with my wife's brand new 22/45 Lite.  Tandemkross has an excellent video on tuning Ruger pistol mags and I'm going to give that a try.  One of the symptoms (among others) is the first round chambers manually and the next cycle doesn't even strip the round out of the magazine.  Also we jams similar to the one pictured.  She's doing well with the gun transition from SS to RFPO in steel challenge, but no sense in shooting a match until we (I) can iron out the feed issues.

[jcc7x7]

I feel your pain.

Three months and probably 3-4000 rounds of ammo through the new MKlV lite.

I've done the Tandamcross and Wirthwien tune on the mags.

bought 4 new nickel plated mags and they are now actually running without any mod's.

 

Original factory one runs , the other will run with the front feed lips closed so much that you can't use the cool plastic magazine feeder on it but loading by hand it runs now.

 

Honestly I think it just finally got broken in.

Cause one time it was finicky, went home cleaned it and lubed it, put it in the safe and went and bought an old MKll

It runs perfect, so I drilled and taped it and mounted an optic.

But

Just could give up on the lite, so took it out with the MKll to sight it in and play with the lite.

Both ran over 250 rounds perfect with all mags.

Shooting Fed. Auto match and CCI Blazer 40gr . 

 

Keep messing with it you'll get it.

Lots of good mag info on the Ruger site, couple of guys are real knowledgeable and share on most threads about mags and feed issues.

 

Got rained out and family stuff last two SC matches but looking forward to using it in the next one

 

 

[Dirty_J]

I also grabbed a couple of the stainless mags. Ran like a top in mine, so I grabbed 4 more snd ditched the blued mags the gun was giving me trouble with (through after tuning they were running ok) 

[Polaris13]

I went through the same problem.  Did the Tandemkross magazine mod and that helped, but didn't cure the problem.  I did notice a small sharp edge where the feed ramp meets the barrel.  I used a drum shaped Cratex in my Dremel to remove the sharp edge.  I barely removed any metal.  This helped more, but didn't cure it.  I found that this gun "broke in" and has turned into a reliable laser at about 1200 rounds.  Cleaning made no difference.

[Dirty_J]

20 minutes ago, Polaris13 said:

I went through the same problem.  Did the Tandemkross magazine mod and that helped, but didn't cure the problem.  I did notice a small sharp edge where the feed ramp meets the barrel.  I used a drum shaped Cratex in my Dremel to remove the sharp edge.  I barely removed any metal.  This helped more, but didn't cure it.  I found that this gun "broke in" and has turned into a reliable laser at about 1200 rounds.  Cleaning made no difference.

Also noticed an exceptionally sharp transition from the ramp to the chamber on mine. Also softened and polished it. 

 

Between that and swapping to all new stainless mags, mine seems to be sorted out. 

[Shrek1]

I am having a lot of issues running any type of ammo and will try the mag fix.  Running a Mark iv. Its frustrating that there are so many malfunctions.  Even purchased some hot loads 1600 fps, worked great for a few mags then started having issues again.

[jcc7x7]

After about 6000 rounds mine is starting to run without issue.

Never thought a Ruger Mark (anything) had to break in.

But

It seems to be running now with about any ammo.

I bought 2 more mags (Nickle ones) and didn't do anything to them and they run.

Going to deburr them just cause I always do, but they ran about 500 rounds out of the package!

 

Maybe just needs more ammo through it

 

Edited September 30, 2019 by jcc7x7

[JHB]

I had that problem. The first thing I did was the TK mag tune and break the sharp edge on the chamber. Out of six mage five are blue. The next thing was remove the mag eject plunger and spring. Last I replaced the extractor. Every step the feeding became more reliable. Over at rimfirecentral they have quite a few threads on this problem. The last recommendation was replace the mag release with an aftermarket one. 

What annoys me the most about this my S&W Victory fed everything right out of the box no tuning or troubleshooting and cost me $250.00 less.

[accu9]

On 9/30/2019 at 4:59 PM, JHB said:

The last recommendation was replace the mag release with an aftermarket one. 

Replacing the stock mag catch on my MKIV 22/45 lite with an aftermarket extended catch (VQ) did the trick for me. The factory catch was not holding the magazine high enough (maybe 1/16th low) which caused the rounds to impact the bottom of the feed ramp.