Magazine tuning help?

[Rigby275]

Hi all -

I recently bought a Taurus PT1911, and the only issue I have with it is that one of the factory mags somehow causes the last case to eject rather weakly, more-or-less vertically.

I ordered a pair of McCormack Super Mags.
One of them does essentially the same thing.

The other two work fine, so seems it's not a prob w/gun or ammo.

They do eject, so it's a problem more because the hot case usually falls on my head, hands or arm - n.g. in a serious situation! 

I could buy more mags and hope for proper function, but I feel sure it's a matter of a small adjustment somewhere.

Anyone have similar experience, thoughts or fix?

Thanks.

regards,

[ButlerFord45]

When John Browning designed the magazines to go with these pistols, he put a nipple in the middle of the follower to prevent this very problem.  Simple physics-inertia- replace the spring or follower or both and you should be good to go with both mags or return the malfunctioning mags-I'll bet that at least McCormick willl exchange a faulty magazine.

[1911crazy]

When John Browning designed the magazines to go with these pistols, he put a nipple in the middle of the follower to prevent this very problem.  Simple physics-inertia- replace the spring or follower or both and you should be good to go with both mags or return the malfunctioning mags-I'll bet that at least McCormick willl exchange a faulty magazine.

Now that i think of it your right about the last round not loading correctly. I'd replace the follower and spring.  On my sks with the orginal chinese 20rd mag the last three rounds would go into full auto fly out mode by escaping from the magazine without chambering when the bolt opened up with the 4th round fired.  I noticed it was the follower because it was off center in the mag.  A little bending fixed the probem. Now i need to get somemore experience with the 1911 mags.  I have mastered every sks mag that didn't function and i have got them all to work. Its a learning process too and its fun when we figure it out and finally make it function.

[ButlerFord45]

I misunderstood your problem-disregard previous.

[Rigby275]

I'll try swapping first the follower then the spring between the good & "bad" mags - mebbe I can isolate the prob, then try adjusting which ever seems to be the cause.

Results to come.........

regards,

[ButlerFord45]

Best of luck!  Intrested in how it turns out.
Sorry, I pictured the last round ejecting straight from magazine with the ejection of the last fired case.

[williamlayton]

I had this discussion with my guru, Vandenberg, the other day.
He said tuning was a misunderstood cure-all.
He took a .45 that a customer had brought him because it did not work with "X" expensive mags he had bought.
These mags were just a thousandth or two longer than than the less expensive ones.
He said, that in order to make "X" work there was some internal work that was required--or that the lips needed adjusted. The internal work wold make "X" work but probably not the others.
Adjusting lips--unless it was accurately done--could create more problems than it solved.
He suggest--and this is what he does, with his race guns--is find a mag that works and only use that kind on this weapon.
I know nothing of gunsmithing but I support one who does.
Blessings

[Rigby275]

Well,I swapped followers within each pair, loaded & fired a handful of single rounds in each and the previously problem ones only vertical ejected ~1/2 the time.

But the previously good ones now do it ~1 outa 5.

Thanks to all for the input so far - still looking tho'. 

regards,

[Mikey]

OK, let's look at the pistol then.  How many rounds have you fired?  How did the pistol eject when it tossed the spent casings - where did they land - how far and in what direction?  If they do not eject far or basically drop right by your feet you may have some burrs or wearing of parts that are preventing the slide from moving smoothly to eject the spent cases. 

Remove the slide and examine the pistol - do you see any wear marks on the ejector?  On the barrel or slide??

What does the fired and properly ejected cases look like at the rim - you should have one possible mark where the extractor claw interfaced with the casing and pulled the case out, and there should be another mark on the rim where it was impacted by the ejector.  If you have any marks or scrapes on the face of the rim it could indicate a too tight extractor which may be holding the last case a bit too forcefully.  With the slide removed take a loaded round and slide it up on the bolt face and underneath the extractor - the extractor should hold it in place.  If it is difficult to get the rim up and under the extractor it may be too tight.  If the extractor does not hold the cartridge in place it may be too loose. 

In some cases the spent cases actually impact on the next round in the magazine which forces them to eject but not so with the last round. I would check the extractor, ejector and points of wear on the slide and barrel too.  You may need a new recoil spring if the one in the pistol is too heavy for the loads you are shooting.  Let us know.

[Rigby275]

Hi Mikey -

I've run only ~180 rounds thru the 2 original mags and ~ 100 more thru all 4, so no wear noticeable.
Early on, I noticed brass dots on the slide, 1/4" behind the ejection port, on the radius, 5:00-ish.
Presently, there are ~ 12 separate dots.
I don't know what this may indicate, but may be from those last cases falling on the slide.

Normal ejection path is variable - 8 to 12 ft, 3:00 to 6:00, with ~ 60% 10'-ish @ 4-4:30.
But the problem ones are always the last round from only 2 of the 4 magazines, prior to the parts swap.

Cases have a slight rim burr (surely extractor) and an ejector mark, tho' no face marks.

Wilson Combat has a page on proper extractor fit (http://www.m1911.org/technic2.htm), and if I've understood the procedure correctly, mine passes the tests, tho' the burrs mentioned indicate some ejector polishing is in order.

Loads are mostly 255 gr cast SWC/5.5 Unique/835 fps/SD 10.xx, with 30-40 200 gr cast SWC/7.0 Unique/940 fps., both showing the problem.

Recoil spring is factory, and I assume 16-18#, but I couldn't swear.

regards,

[1911crazy]

I purchased a while back the G.I. 7 shot 1911 mags from JG sales.  All 6 seem to work ok.  (cheap mags)  Now i hear most of these mags don't work.  I have two of the orginal G.I. mags with stampings that one seems to jam all the time.

I find that replacement mags have to be tuned some of the time.  I have also found that no new mag can be certain it will work in any gun.  Lets say i have 6 rifles of the same manufacturer.  When i tried to interchange the mags some of the mags wouldn't fit into the sister rifles.  I also purchased 6 new rifle mags and out of the 6 one wouldn't lock up and work.  After some filing i got it fitted and functioning.  My point is why shouldn't pistols be any different?

[Mikey]

Rigby:  the case rims should not have a burr on them - you may need to 'tune' or polish your extractor.  I believe, think or feel that the brass dots on your slide are from the empty cases dinging the slide and from the location you describe, 1/4" to the rear of the ejection port and on the radius indicates that the extractor is holding the empties too tightly to allow the ejector to fully or completely eject them and that they finally get ejected when next round is striped up from the magazine and pushes the empty up so that the case mouth hits the forward edge of the ejection port and is then flipped back so that it 'dots' the slide as the loaded round is chambered. 

I forgot to ask you to check your fired brass to see if the case mouth is crushed or bent in or deformed insome way; if so, the problem is your extractor and it needs 'tuning' or polishing, and then I think your pistol should run just fine.  HTH. 

[Rigby275]

1911 -
I agree & mebbe this is a case in point.  

Mikey -
In fact, last-case mouths from the problem MCM mag will be severely slapped into the upper front lip of the slide ~ 1 in 4 shots, cut in 1/8" or so.
The slide locks back, so the extractor must be holding them in such a way as to allow the ejector to kick 'em at a low angle.

The Wilson site noted above says a loaded round centered on the extractor should hold during light shaking, which it does, tho' the round will flop around a little as the slide is rotated around the plane of the bore.
An empty moved down .090"-ish below center should hold under light shaking, which it does also, again with "flop room".
In fact, the hook sets visibly forward of the inner rim face.
So it's not tight in any sense of clamping the case to the slide face, but that may not be all of "proper extractor fit" under dynamic conditions of firing.

Again, I'll emphasize that only last cases are affected, but I'll also note that tests of single rounds fired w/mag removed reacted similarly, some ending at my feet, some out 10' @ 4:00.

A thought, considering all the discussion/observations so far, with particular reference to the gap between hook and rim noted above:
Empty mag or no mag, with no "next round" to ride on, cases can be slipping downward, more or less, as the slide goes back.
The ejector hits them closer to case-center than normal, and they rotate about a variable but lower "pivot point" on the extractor hook, into a more vertical angle.
Cut case mouths occur when the case is even lower in the extractor and the path can't clear the slide.
Sound right?

Mebbe not a mag problem at all.
Is the rim-fit in the extractor possibly too loose?

Further examination of the extractor definitely seems in order.

regards,

[jimster]

But the problem ones are always the last round from only 2 of the 4 magazines, prior to the parts swap.

The other two work fine, so seems it's not a prob w/gun or ammo.

Well I'm thinking if you have two mags that never do this, I would look at the mags and not the gun at this time.  If it was the gun I would think your other two mags would have messed up a few times.  That does not seem to be the case.  If it were me I would concentrate on mags only to start with.

Well,I swapped followers within each pair, loaded & fired a handful of single rounds in each and the previously problem ones only vertical ejected ~1/2 the time.
But the previously good ones now do it ~1 outa 5.

You succeeded in making two mags stop working that worked before in your experiment, that was a good experiment and it tells me something.

You can buy a couple of follower and spring kits and experiment, or invest in a couple of well known brands and experiment with new ones.  
I would keep experimenting with the mags based on what you have said.  If you come upon a couple more mags that work all the time to go along with the two you already have that work, you probably found your main problem. I would look at the extractor after your experiments with followers, springs, and other types of mags. The main problems are usually mags, extractor and ammo, but you want to be sure you cover all the bases on mags before you move to another part, I'm still thinking if you had two mags that always worked and didn't mess up, until you changed them...your experiment paid off, you have to trust that and go with it some more.  Most any trouble I ever had was with mags/followers/springs, extractor next after that. Your extractor sounds like it has normal tension on it to me, the round should flop around and not be tight to the face, it only needs to capture the round, you don't want it too tight or the rim will have trouble sliding under the extractor when it feeds from the mag.  Mine is pretty darn floppy.

My opinion is mess with the mags for a while longer before you look at another part. You still have two mags that work all the time, there is a reason for that.

Good luck!