Another Reason to Rotate Carry Ammo

[JohnKSa]

How often should one cycle ammo through the mag, or does it matter? Does keeping a mag packed for extended periods have any effect on the mag?

Just like anything else. If it's designed to last and manufactured properly using good quality materials it will serve its intended purpose with no problems.

If the designer chose to maximize capacity at the expense of spring life, or if the manufacturer cut corners while making it or used inferior materials then it won't last as long as it should, no matter how it is used.

This topic is always fun as the responses are almost always based on the assumption that everything is perfect. Design that doesn't over-compress the spring, properly manufactured spring, best quality materials, etc. Of course, we all know that's how it is with everything, right?

Besides, it doesn't even matter. Who in their right mind would fully load a magazine, leave it unattended for years and then bet their life on it working perfectly? Check it once in awhile and see if it still functions--I mean, it's only your life at stake, right? If it doesn't, replace the spring--springs are cheap and easy to replace. If the next spring doesn't last either then maybe consider downloading by a round or two to take some of the stress off the springs. The last little bit of compression is what really stresses a spring.

 

[rondog]

It's been said a million times - leaving magazines loaded DOES NOT weaken the springs. What weakens springs, any kind of springs, is cycling them. The repeated compression/release cycles is what wears springs out, not leaving them compressed for years. Unless they go through a severe fire of course.

 

[steveracer]

What he said^.
Many years ago, some of my friends and I happened upon over one hundred 1911 magazines that had been left loaded since about 1918. They had WWI lead ball ammo in them, and were the two-tone lanyard ring mags, which of course now cost a bloody fortune.
We shot all the ammo from each of the magazines in modern-ish 1911 pistols, to include a Springfield Mil Spec, a commercial Colt Commander, and what was at the time the very new Sig 1911.
Every single round fired. Accuracy was even good.
Every single mag worked as designed and locked the slide open on empty.
This was I think 2001 or 2002. They had been sitting loaded for more than 80 years, with 7 rounds in each one (although one had only 5 rounds in it for no apparent reason).
Stop worrying about leaving your mags loaded. From time to time I will take an AR magazine off the shelf in my garage and fire it at the range, some of them have been loaded since 1996 or so. None of them ever do anything besides work perfectly.
These folks with the "guidance" of loading only 28 rounds in an AR mag, or rotating loaded carry mags for their pistols are just plain wrong.

 

[JohnKSa]

It's been said a million times - leaving magazines loaded DOES NOT weaken the springs.

It doesn't matter how many times it's been said, it's false.

I just finished up one test that I ran for about 2 and a quarter years and the springs in both tested mags (one Glock 20 mag, one Ruger P95 mag) definitely weakened and clearly shortened from being left loaded. Not enough to cause functioning problems, but definitely enough to be measurable. Both mag springs shortened by about 7.5%. One spring lost about 5% strength (the G20 mag) and the other lost about 20% strength.

And those were mags from quality gun makers. It stands to reason that as quality drops one could expect more weakening.

I happened upon over one hundred 1911 magazines that had been left loaded since about 1918.

Which tells you that those particular magazine springs didn't weaken enough to cause malfunctions after being left loaded for long periods. It doesn't tell you that all magazines will perform the same, nor does it tell you that those magazine springs didn't weaken at all.

I've got another test running that's been going for a little over a year. This test started with several identical mags, some of which are cycled, some of which are left loaded. I've only got one data point so far, but it looks like the mags that have been cycled but not left loaded aren't losing any detectable amount of spring strength.

 

[Kevin Rohrer]

This is much to-do about nothing, and looks more like a reason to sell ammo than anything else. If you are overly concerned about the priming compound falling apart (a difficult thing to do and not likely to ever happen), shoot your carry rounds out once a year and replace them with new rounds.

Next.

 

[coloradokevin]

1) This problem is probably overblown for most people. I keep my gun loaded at all times, so the only time the ammo is cycled through the chamber is when I unload the gun to practice with it. When it is reloaded there is only a 1 in 52 chance that I've put the same round back in the chamber with my duty weapon, and a 1 in 23 chance that I've done so with my CCW gun. At work we cycle our ammo on a 3 year basis. At home I've shot ammo that was loaded in the 1930's without issues.

2) The idea of needing to worry about a loaded magazine wearing on a spring is nothing short of urban legend. I have original magazine springs in one of the two duty-approved guns I keep at home. That particular gun has had the magazines loaded continuously for over 11 years. It has also been shot approximately 12,000 times. No problems.

Should you eventually rotate duty ammo? Yeah, it's probably not a bad idea. What is the likely outcome if you fail to rotate duty ammo and someday need it? It will probably work fine.

 

[blarby]

This is much to-do about nothing,

Given the jeopardy the officer in question(s) life was placed in due to not understanding the criticality of this procedure, i'd certainly say that its "Much to do about Something".

 

[MIL-DOT]

A great thread that probably doesn't get as much exposure as it should.

Another issue that's directly related is keeping mags jam packed for years on end. I've heard folks say they keep carry mags loaded 2-3yrs+ without being cycled, and others that break them (mags) down and replace springs annually.

How often should one cycle ammo through the mag, or does it matter? Does keeping a mag packed for extended periods have any effect on the mag?

Actually,this has been satisfactorilly addressed, ad nauseum, over many years.
It is the repeated CYCLING of the mag spring that causes them to weaken, not a single, long-term compression.
This subject has gotten a hella lot more exposure than you seem to have run across.
(as goes the old saying....."Google is your freind". )

 

[Mal Cap]

In a semi-auto I ink mark the chambered round so that I know to rotate it and shoot it at the range. With defense rounds I would also mark and rotate but keep in mind not to let the ammo get recycled to much because it also mars the edges of the rim.

 

[luzyfuerza]

This question is something that can be tested fairly easily. I figured that if carry ammo is so fragile that manufacturers recommend that it should only be chambered twice before being fired, then cycling it through a gun a few times should begin to induce failures.

I had some carry ammo that needed to be replaced, so I took it to the range yesterday to see if could induce some failures. I took four rounds and cycled them manually through my gun ten times. I didn't baby these rounds when they ejected from the gun...they were bouncing all over the table, falling on the ground, etc. Bullets and cases collected dings and burrs. I made sure to release the slide so that it dropped at full velocity. Each round fired properly after this abuse.

I repeated this with another four rounds, except that I cycled them through the gun 35 times. Each round looked pretty hammered afterwards, but fired properly after 35 cycles.

I compared the abused rounds to rounds right out of the box, and did not notice any bullet setback, but I did not measure OAL.

This test has a small sample size (only four rounds per test), involved only one brand of ammo (Ranger T-series) and only one gun (full-size XD in .45 ACP), and there's nothing magical about cycling it 35 times, so it is indicative rather than conclusive. However, I'm not too concerned about my ammo being fragile in my gun over the long haul. There are bigger things to worry about in life, I think.

 

[JohnKSa]

This question is something that can be tested fairly easily. I figured that if carry ammo is so fragile that manufacturers recommend that it should only be chambered twice before being fired, then cycling it through a gun a few times should begin to induce failures.

They're not saying that the ammo will fail after X chamberings, they're only saying that they guarantee it WON'T fail for X chamberings. Basically it tells you two things:

1. If you want the manufacturer's assurance that it will work without issues, don't chamber it more times than that.
2. If it fails after X chamberings, don't bother complaining to the ammo maker.

The fact that a manufacturer only warrantees/guarantees something to function for a given period doesn't imply that it will fail immediately after that period. Think about cars. Even after the guarantee/waranty expires, the car will almost certainly still provide many years and many thousands of miles of service. It's just that you can't hold the manufacturer responsible for breakage any longer.

Also, different guns stress ammo differently during the loading process. Some guns slam the rounds pretty hard into the feed ramp, others drive it nearly straight into the chamber with only a little bump off the feed ramp.

And different ammo has differing levels of tolerance to being fed. I have noted, for example, that aluminum cased ammo sets back far more easily than brass cased ammo. I had one batch of aluminum cased ammo that would set back after just one or two chamberings in a particular pistol I owned at the time.

Your test shows that using that particular ammo (maybe even just that particular lot of ammo), and that particular gun together allows a number of chamberings without much chance of causing a negative event.

Another gun with another type of ammo (or perhaps even a different lot of the same type of ammo) might fare very differently.

 

[Schwing]

The extractor doesn't generally cam over the rim. Generally the round slides up the breechface and the rim slides behind the extractor claw.

Most guns aren't designed to allow the extractor to cam over the rim and it's possible to damage the extractor by loading rounds directly into the chamber and dropping the slide. In general, if the manual/manufacturer doesn't explicitly advise that it's acceptable to direct-chamber load, it's better to avoid it.Or with an external extractor that isn't designed to snap over the rim. It can chip or break the extractor claw.

This is good to know. I have been doing this for years, luckily with no issues.

 

[JohnKSa]

It's possible that the gun you're using is tolerant of the behavior--some are made to handle the stresses.

 

[Kevin Rohrer]

I wonder how many hundreds of times he chambered that round to get the compound to fall apart? Or perhaps the assembly process was in adequate?

I carry everyday all-day and only chamber the same round MAYBE once.