deformation of shotshells in magazines?

Highly unlikely with plastic shells, IMO. They dont deform in a box when they are stacked several boxes high on a shelf.

ColtPythonElite said:

Highly unlikely with plastic shells, IMO. They dont deform in a box when they are stacked several boxes high on a shelf.

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They are not under spring pressure against feed lips when stacked in boxes. Plastic shotshells will NOT deform over time in a box, even in a stack, since the container distributes / supports the weight.

mljdeckard said:

I have been telling a few friends about it, and one wondered if leaving shells in a magazine over a long period of time would result in mis-shapen shells which will fail to feed?

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Plastic shotshells will NOT deform over time in a tube magazine, because the spring pressure is fore/aft along the shell and it's shape naturally resists deformation in that plane.

Plastic shotshells WILL deform over time loaded in a box magazine; the spring pressure pushing the shells upward into the feed lips will ovalize the shotshell mouth, and you are likely to experience feed issues once that happens (oval shape doesn't fit in the round hole of the chamber mouth any more).

This has been pretty conclusively demonstrated, so no guesswork needed. I was able to induce this failure with my Saigas.

rbernie said:

They are not under spring pressure against feed lips when stacked in boxes. Plastic shotshells will NOT deform over time in a box, even in a stack, since the container distributes / supports the weight.

Plastic shotshells will NOT deform over time in a tube magazine, because the spring pressure is fore/aft along the shell and it's shape naturally resists deformation in that plane.

Plastic shotshells WILL deform over time loaded in a box magazine; the spring pressure pushing the shells upward into the feed lips will ovalize the shotshell mouth, and you are likely to experience feed issues once that happens (oval shape doesn't fit in the round hole of the chamber mouth any more).

This has been pretty conclusively demonstrated, so no guesswork needed. I was able to induce this failure with my Saigas.

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How long did it take before the plastic hulls deformed to the point of misfeeds in the Saiga magazine? (I don’t have one, just curious.)

Stay safe.

I don’t know the minimum time, but I do know that three months on the shelf was enough in my case.

Fully stuffing a box mag caused some issues for me. I tried loading box magazines one round short of full and it helped some. I can't say it fully fixed the problem, but I haven't left them there for more than a month or so at a time. Never had any issues with a tube magazine using modern plastic hulls.

rbernie said:

Plastic shotshells will NOT deform over time in a tube magazine, because the spring pressure is fore/aft along the shell and it's shape naturally resists deformation in that plane.

.

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I disagree as I've seen it happen. The longer the tube the more spring pressure and the quicker it happens.

It may not in a short mag tube with a weak spring.

Over time the plastic hull gives, cracks, swells, buffer material seeps out, and it can get stuck in the tube.

Shivahasagun said:

I disagree as I've seen it happen. The longer the tube the more spring pressure and the quicker it happens.

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Over what time frame? Like a lot of people I leave my HD shotgun loaded with a full tube so I am curious how long you took to deform hulls. Mine has been that way at least 10 months. I checked the hulls about 3 days ago and didn't notice any deformation.

I have an 870 with extended mag, no problems with 10rds of various loads sitting for over a year.
I have a pump 12ga with 10rd Saiga mag. No problems with bird shot up to #2 deforming, but 00 buck will. So now I keep the first couple rds #4 and buck shot after that.

As everyone has stated, leaving plastic shot shells loaded in a box magazine will deform them over time. This is a common issue with all box magazines.

herrwalther said:

Over what time frame? Like a lot of people I leave my HD shotgun loaded with a full tube so I am curious how long you took to deform hulls. Mine has been that way at least 10 months. I checked the hulls about 3 days ago and didn't notice any deformation.

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I saw shells start deforming in less than 2 years in a shotgun I had. (Wasnt a gun I was using, obviously)

A relative had shells coming apart in about 5 years.

In Police use, 870's being loaded and unloaded alot with the same shells would make shells come apart eventually. Saw it.

I inspect shells kept in my ready Mossberg every few months or just fire them.

I can see plastic shell getting a little deformed when loaded in a tube magazine for a long time if the gun was in the back of a hot truck in the summertime.

mljdeckard said:

Why would #4 be less vulnerable than 00?

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Nah.

Inspection and rotation solves the issue.

Plastic shotgun shells absolutely WILL deform in a tubular magazine.

I once loaded 6 rounds of Federal 00 buckshot in a commercial Remington 870 that had been fitted with a new factory magazine extension.
It was stored in an un-air conditioned but not overly hot room during a summer. After 1 and a half months I checked it before using it and found the shells had compressed and begun bulging between the case head and the shot.

This has been known for years, and seems to be seen more in police guns stored in an upright shotgun rack in a patrol car, especially in warm weather and in a bouncy old car with a worn suspension.

Once they start bulging there's nothing to do but shoot them in practice because they can't be "rested"....as soon as they're loaded back in the gun they start bulging again.

Bulging seems to be more common with cheaper plastic shells and foreign made shells where the plastic or construction may not be up to USA standards.
Bottom line is, if you leave a tubular magazine shotgun loaded you better be checking the shells at least monthly.

I've also had rounds deform from being left loaded in tubular magazines...most recently Federal LE13200 left loaded in my Winchester 1200 for a few months (stored in my climate-controlled bedroom closet). Most of the shells had a noticable bulger in the middle, and one deformed the star crimp enough that it was losing buffer material inside the mag tube and receiver.