need help and advice with a Wilson 920 failure to feed issue.

[jar]

I have a couple new Wilson Combat 8 round magazines that just enjoy giving me grief. When I first tried them the recoil ejected the magazine on every shot.

Even though this was just with the new Tisas US. Army 1911A1 the only thing I could think of was that perhaps the magazine release button spring was weak. It only happened with the two Wilson mags, all the other magazines I owned, new and old worked just fine.

Even though the pistol that was ejecting the magazines at every shot was new I ordered some new Wolf factory 1911 magazine release springs and put a new factory spec spring in the magazine release and that solved the ejection problem.

But both of the 920 magazines still fail to feed the last round in the magazine consistently and in three different Tisas 1911s. None of my other magazines have that issue. Other magazines are from Mec-Gar and Check-Mate and Ed Brown & Colt (likely also Check-Mate). About half are 7 round and half 8 round. Some relatively new and others decades old.

The Tisas are the "U.S.Army" full size version, the "Carry" which is an enhanced commander size and a "Tanker" which is also commander size but only GI sights, trigger and hammer. All are series 70 internals and all have a polished feed ramp.

What I find really strange is that if I load a single round it always chambers correctly but if it is the last round of several it fails to feed. The symptom is nose to feed ramp and a tap rack will chamber the round. It's the same in both the longer slide and the two shorter slides pistols. Both magazines do lock slide open on empty. Finally whether I load two or five or seven or eight rounds the last round fails to feed.

The biggest difference I can see is that the 920s are among the examples I have with the narrow GI follower. Most of the others have the wider enhanced follower or a hybrid follower but two of my Check-Mate magazines also have the narrow GI follower and work as they should

I'm quite frankly stumped on this one.

These magazines will only be used as range mags so this is not a serious issue but really more just a "That's Strange!" moment. More an annoying itch right below the back of my neck where I can't quite reach.

Open to any and all suggestions.

 

[L-2]

https://shopwilsoncombat.com/MAGAZI...20-SERIES-BLACK-OXIDE/productinfo/920-45FS8B/

or

https://shopwilsoncombat.com/MAGAZI...D-920-SERIES-STAINLESS/productinfo/920-45FS8/

I think the referenced links are the subject Wilson-Combat mags.

I've had some problems with various 1911 mags (.45ACP) over the years. I've never owned or tried Wilson's 920 model mags, however.

While at the range, I'd want to swap in the followers & springs from the other mags which I owned to narrow down the variables of mag body, spring, follower.

Not asked, but an "fyi", this Tripp Research kit, so far, has worked in any 1911 mag body I've owned, but it does make the mag into a 7-rounder:
https://www.trippresearchinc.com/super-7-upgrade-kit/

 

[jar]

The black oxide versions. They don't have the little body dimple (they do have the follower dimple) so don't slide in easily but except for the issue above work great and would just be range mags anyway.

I've looked at the Tripp kit but with shipping it's about what a new magazine would cost so looking for other ideas first.

 

[Steve in Allentown]

But both of the 920 magazines still fail to feed the last round in the magazine consistently and in three different Tisas 1911s.

. . . if it is the last round of several it fails to feed. The symptom is nose to feed ramp and a tap rack will chamber the round.

These two statements lead me to suggest that you call Wilson and ask them to send some new magazine springs which they will do for free.

Have you ever disassembled those two Wilson mags? There's always the possibility that you put the springs in backward although I kind of doubt it. In any event, Wilson will send you new springs at no cost to you. It's entirely possible the original springs are weak.

 

[Nathan]

Do you ever get any bolt over base malfunctions? This is common with weak mag springs.

 

[jar]

The magazines are new and never taken apart yet. And I have emailed Wilson to see what they say. The springs in both magazine do feel softer than expected.

And of course I have NEVER put a magazine in backwards. Well, almost never.

AbE:
Actually I just got a "Thanks for the update" email and case closed. I really don't think they actually even read the whole message I sent.

 

[jar]

No other failures to feed, fire or eject except on the last round.

Weak springs are likely but then why do they always feed perfectly with just a single round in the magazine?

 

[L-2]

Forget the Tripp Research Super 7 Upgrade Kit suggestion.

Again, try substituting in other, presently owned, mag springs and followers from your other working mags (your Mec-Gar, Ed Brown, Checkmate, and Colt mags). OP will need to do the work. We can't i.d. and determine the cause from where we all sit.

Steve in Allentown knows his stuff and suspects the mag springs.

Another factor (my apologies if I missed it in reading) is the ammo. I didn't notice what ammo was being used, such as factory new brands and models, or someone's reloaded ammo.

 

[jar]

Factory 230 ball. UMC, R.P and Browning.

AbE:

I don't doubt for a second that changing the innards would solve the problem but that is really unimportant.

What I really want to understand is why it feeds the first round when there is only a single round in the magazine but never the last round when there are more than one rounds in the magazine. The spring tension on the follow should be the same whether it's the last round or only a single round fresh load.

Solving the problem is pretty much irrelevant while understanding the issue is extremely important.

 

[Steve in Allentown]

Weak springs are likely but then why do they always feed perfectly with just a single round in the magazine?

Because you're manually feeding the single round instead of allowing the pistol to auto-load. Of course, with a single round in the mag and an empty chamber there is no way the pistol can auto-load that single round that is in the mag.

The forces in play during live fire cannot be duplicated by manually manipulating the pistol.

 

[jar]

The differences might be in timing but the cycle should be the same whether recoil generated or simply sling release.

But the question remains why are the two Wilson 920 magazine displaying the same symptoms in three different guns?

What would be different but magazine specific?

 

[Jim Watson]

Wilson 920
"Hybrid lips"
GI follower
8 rounds

I'd contact Wilson and let them figure it out.

 

[jar]

Yes, I did contact them but so far with no suggestions.

As I said above, it's not a big issue rather it really bugs me that I can't understand what is happening.

Sorry but I guess there goes another cat.

 

[Steve in Allentown]

The differences might be in timing but the cycle should be the same whether recoil generated or simply sling release.

The mechanical movements are the same but the dynamic forces are very different.

But the question remains why are the two Wilson 920 magazine displaying the same symptoms in three different guns?

Jim listed the features of the 920. Here's the major problem with the magazine. It's a flush fit 8 round magazine. Regardless of the marketing hype in Wilson's description of the mag, 8 round flush fit mags wear out the magazine spring faster than 7 round mags. Go to this LINK to find out why. I again suggest you ask Wilson to send you a couple of mag springs for free because yours are toast.

 

[jar]

I know the features of the 920 and the magazines are brand new, only three trips to the range and under 75 rounds total.

I have contacted Wilson but so far they have offered no suggestions. And in this case the number of rounds loaded in the magazine seems to make no difference.

 

[Steve in Allentown]

I know the features of the 920 . . .

Did you know that stuffing 8 rounds into a flush fit magazine would significantly decreased the spring's service life?

. . .the magazines are brand new, only three trips to the range and under 75 rounds total.

In other words you just can't believe that springs in new magazines can be anything other than perfect. In a mass production environment there will always be a percentage of less than perfect parts. You just happened to get a piece of that percentage with these two WC mags. FYI, this is not an uncommon occurrence.

And in this case the number of rounds loaded in the magazine seems to make no difference.

Let's explore this a bit just so I understand exactly. This is what I took from your description of the failure-to-feed. Please correct me if my interpretation of your words is incorrect in any way.

SCENARIO #1
With a magazine loaded with more than 1 round, the first round in the mag is manually loaded into the chamber. After it is fired and if there is more than single round remaining in the mag, the slide cycles and the pistol goes back into battery normally. This continues until after firing the next to the last round in the magazine, the slide cycles but the last round in the mag nose dives into the feed ramp causing a stoppage.

SCENARIO #2
If there is single round in the magazine and you manually rack the slide to load that round into the chamber, the round chambers normally and the pistol goes back into battery.

 

[L-2]

This is merely an FYI.

The photo shows a couple of Tripp Research Cobra Mags' springs. The mags were new and used during the mags' initial range outing.

The mag springs actually fractured. Brand new parts aren't always 100%. Tripp did send me a few more mag springs which have worked, so far, for the next 11+ years and counting.

 

[HiBC]

This may be off in left field,but its something to check.
Do the troublesome magazines contact the ejector? They shouldn't,and probably don't, but you have a lot of tolerance stacks there.

That Steve guy knows his stuff. I'd give his way a try.

I don't expect every magazine variant to run flawless in my gun. Even "good" ones.

IMO verify what quality mag runs 100% in your gun with your ammo then buy a bunch and shoot with those. Eliminate variables in the process, (J Edwards Deming)

 

[jar]

Yes, both #1 and #2 are true.

I don't doubt that the issue is weak springs or that brand new things can be wrong.

I'm just trying to understand what might cause the scenarios that you describe.

As I said, it's just killing another cat.

 

[Steve in Allentown]

Yes, both #1 and #2 are true. I'm just trying to understand what might cause the scenarios that you describe.

Let's break down what's happening in each scenario.

SCENARIO #2
One round in the magazine. Empty chamber.

No matter if you're loading that single round from an open slide or closed slide the pistol is not experiencing the dynamic forces that occur during firing. The recoil spring is not suddenly compressing, the slide is not slamming into the frame at the end of its travel, and the muzzle is not suddenly flipping upwards.

As a result of this lack of dynamic forces the single round in the mag is not moving forward or down while the slide is moving forward and so is properly engaged by the slide, pushed out of the mag, and chambered.

SCENARIO #1
Multiple rounds in the magazine. The last round in the magazine is auto-loaded after the next to the last round is fired.

Here all the dynamic forces that occur during live firing are present. This is when inertia comes into play.

"Inertia is the inherent property of a body that makes it oppose any force that would cause a change in its motion. A body at rest and a body in motion both oppose forces that might cause acceleration. The inertia of a body can be measured by its mass, which governs its resistance to the action of a force, or by its moment of inertia about a specified axis, which measures its resistance to the action of a torque about the same axis."

The last round in the mag resists the dynamic forces by attempting to stay in its position in the mag. Essentially, the pistol is moving backwards and upwards while the cartridge is staying in place. As a result, the cartridge appears to be moving forward in the magazine and may escape the magazine. Really what's happening is the pistol is moving away from the cartridge.

Also, the cartridge will appear to push the magazine follower down into the magazine. Really what's happening is the pistol is moving upwards and the cartridge is resisting that movement. What can happen is the cartridge loses contact with the feed lips and floats in the resulting air gap. This can lead to the cartridge escaping the magazine as described above.

The only thing preventing the cartridge from the perceived forward and down movement is the magazine spring. To be precise, the cartridge will always move. The trick is to prevent excessive movement. That is the job of the mag spring.

The magazine spring will exert the most upward force when the magazine is fully loaded and the least amount of upward force when the magazine is empty. The problem with those WC mags is the mag spring is not exerting enough upward force on the last round in the mag to push it up into solid contact with the feed lips in time to be correctly engaged by the on-rushing slide. In fact, that last round may be so far forward in the mag that it's barely being held at the end of the feed lips or it may have completely escaped the mag.

No matter exactly where that last round is located when the slide smacks it, the round nose dives into the feed ramp causing the stoppage.

IMPORTANCE OF THE MAGAZINE SPRING
The importance of the magazine spring to the operation of the pistol has been established. There are a multitude of factors that come into play including but not limited to the strength of the spring, the power the ammo, the grip and body mass of the shooter, etc. etc. There is no practical way to precisely define all of the forces and the interaction of all the factors to determine the perfect strength of a magazine spring. All we can realistically do is work within generally accepted parameters and replace springs that are no longer allowing the pistol to operate correctly.