Home Defense Ammo Cycling?

I would not keep longer than 6 months loaded in magazine. I’ve never reach this period, I’m reloading my magazines all the time (carry, range).
These 6 months limitation is not because of the ammo, it is because of magazine spring that shouldn’t be in compressed state for a long time.


I thought unloading them and loading them caused more wear than leaving them loaded :thinking:. Like you, I use all my mags at the range, so they don’t sit loaded for really long times.

I thought “cycling ammo” was changing old carry ammo for new carry ammo.


Cycling between old and new doesn’t matter… when can we consider ammo as old?
The only “wear” I carry about is round chambered. If it is slammed into the chamber several times, the projectile can move out from the casing a little. In this case I won’t trust this round anymore.



Are you shooting range ammo and then you have a different set of HD ammo. I would probably cycle it a bit more often. Not for wear and year but so you don’t lose the muscle memory of the difference between range ammo and HD ammo. But that’s just me.


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Jerzy, I don’t understand the concept of cycling ammo, Please help clear up the clouds surrounding this.
You made a statement that the round you carry chambered suffers from wear, how, the round in the chamber is located in the most formfitting area on the weapon? Any movment is limited by the bolt face. Rounds in the magazine can and do move, just shake a magazine and you will hear the rounds move slightly, but so what, if they did not move they could not pass thru to the barrel chamber.
At this point I see no reason to cycle ammo just because it is weeks old, it won’t go bad unless stored in some very conditions. As fas as the bullet movment in the chamber, I can not understand how that happens. I understand that revolvers can and do suffer from cylinder lock, due to rounds jumping the crimp, but even this is very rare and is usually is a direct result of a handload being poorly crimped in place.
Please, help me to understand.



There are a couple different concepts floating in here.

Cycling or Rotating ammo…
To me, this is the practice of shooting ALL the SD/HD ammo in a magazine(s), ensuring the mag functions well, the ammo cycles, no failures, and you can hit what you aim at. You then reload that mag(s) with SD/HD ammo and put it back where it was. You should do this on a regular(ish) basis.

Ammo doesn’t “go bad” if it is just sitting in a magazine and not in any sort of weird weather conditions.

Carry ammo is subjected to slightly more stress since its next to your body (hot) and some people sweat (a lot) onto or into it. I dont know where you would draw the line when you can say “i’ve worn this ammo for X years, I’m not sure it goes bang anymore”.

Cycling/Rotating your HD/SD ammo every 6mo/1year is only partially to prevent it from going bad/stale. Mainly it is to make sure that you practice with your carry ammo since it will usually “feel” different from range ammo (recoil) and there is a potential POA/POI shift from range ammo.

If you can afford to dump your carry SD ammo every range trip, by all means go for it. Every 6mo/1year seems reasonable to me, but YMMV. I dont have any scientific data on it, but past 1 year just feels like its too long since you’ve trained with your carry ammo, but that is subject to everyone’s budgets and priorities.

Bullet setback (cycling/rotating ONE round)
Bullet setback is a real thing, although not super common (at least that I’ve heard of). This pertains to the folks who unload/load their magazines in a firearm on a regular basis. For example, your carry firearm goes in the safe each night. You take the firearm out of the holster, drop the magazine, rack the slide to empty the chamber, and set aside the chambered bullet. The next day you put the magazine back in, rack the slide to chamber a round, and maybe put yesterday’s bullet back on the top of the magazine.

What ends up happening is that each time the slide chambers a round it slams into the bullet from the magazine and slams it into the chamber there is the potential for the bullet to get pushed back into the casing just a teeny tiny bit. Where this is dangerous is if the bullet gets seated back too far you end up with over-pressure in the case, causing kabooms in worst case scenario and FTFire in best case scenario. AFAIK, it is a pretty grey area as far as when you can say “this is too much setback”, there is no definitive number such as 50 chamberings is OK, but 51 is not.

If you do this to a bullet once it is no big deal, I doubt its even measurable. But if you “cycle/rotate” that same bullet into a chamber a lot of times, then you begin to see it. I’ve seen “on the internet” where people have chambered a round 50 or 100 times and the bullet will be setback a few millimeters. 100 may sound like a lot, but if you consider the person who cycles/rotates that top round every day putting the firearm in/out of the safe that is up to 365 chamberings for a single bullet and each one is an opportunity for setback.

There are ways to mitigate the risk of setback. Some folks will put a mark with a sharpie each time a bullet is chambered. And if you see a bullet has like a dozen marks on it, remove from rotation. Or they will unload/load the magazine in a different order, or swap the top few rounds, etc.

Is this something worry about? Maybe? If you have been chambering the top round for over a year (365 times) that means you haven’t rotated your ammo (see above) and you’ve been administratively clearing your firearm every day. Possibly just being aware of the potential problem and knowing you’ve chambered this round a lot means you set that one aside.

My carry firearms stay chambered and holstered 24/7/365 unless they goto the range, get cleaned, or practice dryfire. So for me… (and I readily admit this is overzealous and slightly OCD) every time I clear that chamber, that round goes into the “chambered pile” and when I do that enough I end up with a box of SD/HD ammo and I will shoot that ammo at the range and not feel bad about it.


You didn’t understand the meaning of my answer… or maybe I put the words in wrong order, making them not clear… sorry…

So to clarify, what I meant:

Cycling between old and new doesn’t matter

because it doesn’t matter

… when can we consider ammo as old?

that was my question, which I didn’t know the answer… It’s hard to define “old”. I’ve got almost 1 year old Fiocchi JHP ammo, stored in my basement and it still looks and shoots good.

So my point was as yours - no reason to cycle the ammo.

Regarding frequently chambered bullet:
It’s a simple physics. However this depends how do you chamber the round. If you make it light and slow, allowing the round slide into the chamber - all is good. But most people just rack the slide, and round goes to the chamber at faster speed and then stops immediately, but the stop is for shell only. Projectile is still forced to move forward, kept by shell only.

Check this video, it explains better than words.


I cycle my self-defense ammo approximately every 6 months - and I think it’s important to cycle ammo for a number of reasons.

Now I’m not saying you should shoot up everything you have in storage every six months - as fun as that might be. I’m saying the ammo that is in my carry gun is shot every six months.

Why? My carry gun gets warm on my body (not hot, but warm) and sweat is also a consideration in the middle of a humid summer. In winter, the firearm gets cold off body at night. Is there a chance that hot/cold/hot/cold can affect the ammo? Maybe. But that’s not the only reason I cycle ammo.

If you take your self-defense ammo out of your magazine to shoot target ammo when you’re at the range and then put it back in the magazine for carrying, doing that repeatedly can add up to a lot of wear and tear on the round. I’ve seen rounds where the bullet is loose in the casing - not going to fall out loose, but where the bullet wiggles. I do not want to risk any sort of issues with my ammo in a self-defense incident.

ALSO, all ammo can shoot a bit differently. Will it make a huge difference in a self-defense incident? I don’t know, but I want every advantage I can have if I ever have to physically defend myself. Knowing exactly how the ammo will shoot and that it’s in good condition is worth $50-$100 a year in self-defense ammo shot at the range.

If the self-defense ammo is sitting in a magazine in my environmentally controlled safe, I wouldn’t worry about it not functioning correctly. On my body and exposed to the elements and stress, I want to change it/shoot it every six months - ish.


Let’s split this in two. Ammo age with modern ammo is almost irrelevant. I have boxed ammo that is 25 years old and every round will go bang, properly cycle the gun, etc. Every now and then I shoot it, and I’ve literally never had a misfire with old ammo. All my misfires have been with new ammo where clearly there was a bad batch, at least as far as the gun I was using it in was concerned. Of course none of my old ammo has been exposed to oil/grease (which would be the most significant risk as I understand it) or even prolonged periods of high humidity. I still prefer newer rounds for self-defense, but I don’t put an expiration date on them.

Now for the ammo I actually load into magazines and carry…I always fire that off at my next range session. At least the magazine that was in the gun, or the cylinder full for a revolver. Or if it has been sitting around in a gun for a while (which happens with home defense firearms), I periodically switch rounds and take the old ones and designate them for practice. The ones in the gun have a possibility of being subject to oil/grease and, for carry guns, humidity. So it becomes both a way to make sure I’m practicing with the ammo I would actually use to defend myself and eliminating the rounds with the most chance of degradation from the live ammo pool.

And if you pocket carry, keep in mind that lint accumulation is a more significant issue. I’m not sure if there have been studies of how lint stuffed hollow points perform, but I find it best to put those through paper rather than trust they will expand when expansion is needed.

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That makes sense to me. Replacing SD ammo to ensure proficiency with SD ammo. I carry a single stack gun, so cycling through a mag or two of my carry ammo is no big deal. But my HD gun has 15 mags, and I have more than one loaded magazine. That goes from an expensive range trip to a really expensive range trip. I will make sure to run through a mag of SD every few months.

How about a plan like this:

Every time you go to the range, you fire off just one or two of your expensive SD rounds. After a while, you will have likely cycled through them automatically.

No need to arbitrarily determine an expiration date on ammo that theoretically should be good for years. After the first two in the SD mag are used, unload the rest by hand and put the new ones at the bottom of the stack. Kind of a bother as you’d have to keep them in order, but you only have to do it once each time at the range, and we all like playing with our toys anyway, might as well give it purpose.

A widely debated subject… You’d think a properly qualified major gun manufacturer’s design engineer would actually weigh in on this someday. Perhaps one has, and I’ve just missed it.

I do agree with your bullet shoulder stop posit, and how it could pull the bullet from a shell, at least until it starts to seat into the barrel’s rifling. The stop is much more forceful than the slide’s acceleration.


I see what you’re saying and it makes sense to me. I dont know enough about chamber design to fully know what bit on the chamber touches what bit on the ammo. But every time I’ve seen bullet setback talked about the bullet is always pushed “in” to the case.

Aaron at Sage Dynamics was the first place I heard about it. His rule of :+1: is 5 chamberings for pistol rounds and 1 chambering for rifles before he pulls it out of rotation.

You can search for “bullet setback” on google/youtube and there are many articles, videos, etc on the topic. Here are a few…

MAC says eyeball your ammo and if you can visually see a difference then remove from rotation.

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Setback from too many loadings. Hmmm.

How about this: on load up, drop the active round into the chamber by hand and then let the slide lockup onto it? Not necessarily at full speed though. It puts no nose pressure on the round. Then insert mag.

Glock Manuel advises against this. Apparently it can cause failure to feed. (Random fact I’ve picked up here :joy:)


Well, you do have to make sure the ejector locks up to the case, but otherwise, how could it matter?

Appreciate the heads up all the same.


Just checked the manual, and it does suggest proper loading is either releasing the slide catch or racking it. But nothing about what might be improper.

Back to the point of this thread:
Might just have to rotate the first round now and then, when it starts to look like bronze instead of brass or nickel.

Loved VS guy’s silencer shot.
No ear plugs needed.


I cycle my ammo, through my gun. You should be practicing periodically with your carry ammo. So, I’ll just rotate it down the barrel.


Interesting that it can go either way, longer or shorter, per the few videos posted here, perhaps it’s dependent on the particular gun’s barrel, and how far the chamber’s case shoulder is from the barrel thread start (which would tightly support the bullet at seating in the chamber, ideally, at the proper distance so the bullet couldn’t get longer).

Some guns with sharper high angle loading ramps may be more prone to shortening rounds, where other guns with low angle ramps and/or slightly too much distance between the case shoulder and the rifling start, are more prone to elongating them.

I love trying to understand how things actually work, and trying to figure out stuff like this…


I may be right - all probably depends on barrel / chamber construction, so may vary between manufacturers.

I’m a little wary of some ammo, especially reloads, so once I’ve seen problem, I would do everything to avoid it.

For security reason - once my ammo went out from the box, it would be used within month. So far on the Range only. :upside_down_face:

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I cycle.
The practical life span of magazine springs are based on cycles,
Springs are easy enough to change out though.
If you have ten or more magazines and rotate through them you’d have to burn up a lot of ammo to weaken all those springs,
Bullet setback in semi autos is a bigger concern.
Since all firearms at my indoor range have to be unloaded before entry, I simply eject the chambered round and add it to my training ammo cache for the launch.