10/22 Magazine Movement Causing Failure to Feed

[Captains1911]

I'm having an issue with one of my Ruger 10/22s. With a mag fully inserted, I am able to wiggle it back and forth about 1/16", in which it often gets stuck in the rearward position. It also is able to stick in this rearward position upon initial insertion. With my other 10/22s, I am only able to wiggle the seated mags about 1/32", and they always return to the forward position from the spring tension on the magazine latch plunger. The mag sticking in the rearward position is sometimes causing the bolt to hang up in its rearward position during cycling, resulting in failures to feed. When the bolt hangs up, simply tapping up or forward on the bottom of the mag allows it to move into the forward position, freeing the bolt and allowing it to move forward into battery, chambering the round.

This is not a mag issue as it occurs with all of my factory 10rd mags, all of which do not exhibit the problem with my other two rifles. The problem rifle is a newer model with a polymer trigger group, factory extended mag release, and a VQ auto bolt release.

Any help diagnosing this problem is greatly appreciated.

ETA: I've tried swapping the following parts, and with the stock removed, with no avail: mag release, mag latch plunger and spring, bolt release, entire trigger group.

 

[gunsandreligion]

Does the front of the receiver where the front of the mag attaches look different from your other 10/22s?

 

[Captains1911]

Does the front of the receiver where the front of the mag attaches look different from your other 10/22s?

Not noticeably, but I have thought of that. Perhaps I just need to polish that recess some.

 

[RaceM]

Pull the receiver out of the stock and play with a magazine in it to spot the bind. Odds are good there's a burr or casting flash that's the problem.

 

[Captains1911]

Pull the receiver out of the stock and play with a magazine in it to spot the bind. Odds are good there's a burr or casting flash that's the problem.

There are no burrs inside the trigger group, and since the problem persists with different parts and entirely different trigger groups, I'm thinking it must be the receiver.

 

[Captains1911]

Playing with it some more, I discovered that the entire trigger group from the problem rifle causes the mag to stick in another rifle, making me think it's an issue with the trigger group. However, a trigger group from another rifle installed in the problem rifle also causes the mag to stick, making one believe it's an issue with the receiver. Now I'm really scratching my head.

Yesterday I was able to replicate the malfunction of the bolt hanging up by hand cycling the bolt while pushing up and back on the inserted mag. However, today, I am unable to do the same. I guess for now I will wait and see how it functions, but I am still curious as to what is causing the mag to stick, and if perhaps its not uncommon?

One last thing I forgot to mention was that I recently changed from a factory synthetic stock to a factory wood stock. I noticed that the mag well on the synthetic stock is narrower, perhaps just enough to prevent the mag from moving enough to cause the malfunction, explaining why I didn't have the problem with the synthetic stock.

 

[Captains1911]

Just to provide a visual, the problem rifle is on the right. Notice the larger gap between the rear of the mag and the front of the magwell (trigger housing). The second picture shows the mag stuck in the rearward position.