Do all AR's chew-up cycled rounds?

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AKElroy

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I recently acquired my first AR, a Daniel Defense M4V3. It is accurate and cycles flawlessly, but so far the round count is low @ 70 rounds fired.

One thing I have noticed is the amount of damage done to rounds cycled (but not fired) through the action. Cases are dented below the shoulder, and the rounds themselves are gouged-up pretty good. Green tips are no longer green if they are cycled more than twice, and gouges are clearly present on the rounds.

Is this typical of the AR platform? It does not seem to be hindering function or accuracy. I assume a few thousand rounds will smooth-out whatever is causing the damage?
 
Jackal said:
Its quite normal. The bullets get scratched on the way OUT. They shouldnt get scratched on the way in though.
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This makes sense. It would obviously be designed to shuck empties with a shorter OAL. The gouge on the bullet is a 1/2 turn spiral, so it is dragging on one of the lugs as it rotates on its way out. I guess rather than filling up a can with junk ammo, I need to just stop playing with it. It's new, so it is getting cleared and handled a lot. (-;
 
I keep "un-chambered/removed from chamber" rounds in a coffee can for practice use. I dont completely trust them to feed perfectly after being yarded out of the barrel and scraped up.
 
MistWolf said:
Why haven't you cycled enough rounds through yours to already have the answer?
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My rounds go in loaded and come out empty brass.
If OP's rounds are going in loaded and coming out loaded I'd imagine there is something wrong with his firing pin ;)

But really, the sharp edges on the feed lips will scratch up the case, the feed ramp leading to the chamber will scratch up the tip pretty good, and the extractor isnt exactly gentle on the rim.
 
Some feed ramps scratch up rounds more than others, but it is common to the system. I've yet to have a gun dent a case, but that problem is fairly moot if you are shooting the rounds. Any minor dent is going to pop right out when pressure starts building up in the case.
 
If you slowly cycle a round through an AR and carefully watch the sequence it becomes apparent why cases are dinged or slightly dented. Keep in mind also that cases are not typically ejected after firing with the bullets still on them. :) Seriously slowly cycle the rifle and think about what is happening in real time when a live round is fired.

Next, I strongly suggest you quit cycling live rounds through the rifle. There is no reason that I can think of to cycle live rounds through the rifle to satisfy a curiosity. I suggest you find someone who hand loads and ask them nicely to make you some dummy rounds or as mentioned buy snap caps. For any hand loader making some dummy rounds is an easy task. Just my opinion but cycling live rounds through a rifle at home is not a good idea, at the range? Maybe for some testing but that is about it.

If in the Great State of Texas you can't find anyone to make you some 223 dummy rounds feel free to send me a PM and I will make you a half dozen next time I load 223. Yeah, I feel that strongly against cycling live rounds simply for curiosity. :)

Ron
 
Ditto

This^^^^*. Nicely said.
About cycling loaded rounds.....I have not done this in recent memory but I have done it. Mostly it was a crude way to check overall length before I had a tool to do that.
The rounds came out as they went in. That I know. What is all this "scratch" stuff?
 
I keep my rifle loaded/round chambered in my bedroom as a home/farm defense rifle. It gets unloaded for maintenance, modification or show & tell. I have a small pile of cycled rounds that I simply set aside for plinking use. Though it should be noted, I live alone, out in the country. If I was an apartment dweller, had kids or lived with others, I'd likely not have a round chambered in a rifle, in the house.
 
Reloadron said:
If you slowly cycle a round through an AR and carefully watch the sequence it becomes apparent why cases are dinged or slightly dented. Keep in mind also that cases are not typically ejected after firing with the bullets still on them. :) Seriously slowly cycle the rifle and think about what is happening in real time when a live round is fired.

Next, I strongly suggest you quit cycling live rounds through the rifle. There is no reason that I can think of to cycle live rounds through the rifle to satisfy a curiosity. I suggest you find someone who hand loads and ask them nicely to make you some dummy rounds or as mentioned buy snap caps. For any hand loader making some dummy rounds is an easy task. Just my opinion but cycling live rounds through a rifle at home is not a good idea, at the range? Maybe for some testing but that is about it.

If in the Great State of Texas you can't find anyone to make you some 223 dummy rounds feel free to send me a PM and I will make you a half dozen next time I load 223. Yeah, I feel that strongly against cycling live rounds simply for curiosity. :)

Ron
Click to expand...
I am not cycling rounds though the gun to satisfy some curiosity, I am simply clearing the chamber prior it to handling it. Were talking three ejected live rounds over the two months I've had the gun. Thank you for the kind offer, though.
 
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You are an adult (I assume :) ), and can decide how to handle your gun, as well as be responsible for any consequences of your actions. The key points are, scratching doesn't occur on a once chambered round, and any minor dent isn't going to affect the gun, as dents in brass pop out when the cartridge is fired. 55k PSI pushing outwards makes dents a thing of the past fairly quickly, any experienced reloader knows that.
 
Metal magazine feed lips scratch up rounds. It's a source of friction early in their service life, one that Pmags eliminate. Otherwise the lips need to be honed down either by hand work, or by hundreds of softer brass cases wearing them down.

It's a result of being punched from steel sheet and the mag companies don't use expensive blanking dies to keep the edges nicely dressed. Stamping tends to shear and tear the edge slightly, and the problem gets worse as the dies age, same as on other parts of the gun.

Feed ramps are ground into the barrel extension and some will have sharp edges, causing scratches, too. Hand cycling rounds will make it worse compared to letting the bolt fly forward at full speed. With designed velocity from the BCG, the cartridge is less likely to have gravity pull it down into contact with the ramps as much - it flies forward rather than dragging up the ramps.

Self loading actions tend to batter the bullets slightly compared to the smoothly designed gravity influenced manual action guns. That's why you can shoot standard loads in bolt action guns but they might set back in self loaders, and why military ammo is crimped to prevent setback. Full auto does not tolerate low neck tension bullets sitting in cases.

Once fired the case is pushed against the bolt face as it extracts IF the bolt cycling speed is optimal - if overgassed for use with cheap underpowered ammo, or if improperly timed, the case is dragged out by the extractor, then the ejector tilts it to collide with the port opening where it then hits the left hand case deflector. It's basically getting banged out the opening into two possible hard objects. The HK91 series rifles can dent the cases nearly 50% of the diameter, so the AR isn't alone. A manual action rifle never sees the speeds involved and the empties are simply flipped out with contact on the ground as the major hard object.

Most self loading guns have all these issues - shoot more of them and you will see the distinctive marks of each typical of that action. It's not dialogue written for a CSI episode, it's something you can readily see with experience, same as discerning the different sounds of each firing at a short distance away. Spend time under Uncle Sam's careful tutelage and you get to shoot quite a variety - and get paid to do it. But they all share similar traits, and it has to do with getting loaded at combat speed into a chamber and then blown or jerked out for the next.
 
I'm thinking back... I've probably un-chambered a round a couple of times in the years I've owned ARs... and almost never unloaded magazines other than by normal use. I would not use an AR for home defense though - that's what shotguns are for. But I know there are those who do. I don't handle my home defense weapons in general though - they sit and age quietly, waiting for their chance to excel in the face of some potential bodily harm coming my way. They're always in the same place, always in the same state and since they never move, I can easily touch them in the dark of night... in a nutshell, I don't play with my home defense tools... but that's just me!

As a hand loader, I do know that manually cycling any rounds are going to result in slightly mangled examples.
 
AKElroy said:
One thing I have noticed is the amount of damage done to rounds cycled (but not fired) through the action. Cases are dented below the shoulder
Click to expand...

I'm used to a dent below the shoulder on fired brass, not from clearing the chamber.

On one of my rifles that will ding the brass on ejection, I filed a small radius where the base of the shell deflector meets the ejection port opening. It makes the dents less sharp so eases my mind about causing a stress concentration on reloaded rounds.
 
RainDodger said:
I'm thinking back... I've probably un-chambered a round a couple of times in the years I've owned ARs... and almost never unloaded magazines other than by normal use. I would not use an AR for home defense though - that's what shotguns are for. But I know there are those who do. I don't handle my home defense weapons in general though - they sit and age quietly, waiting for their chance to excel in the face of some potential bodily harm coming my way. They're always in the same place, always in the same state and since they never move, I can easily touch them in the dark of night... in a nutshell, I don't play with my home defense tools... but that's just me!

As a hand loader, I do know that manually cycling any rounds are going to result in slightly mangled examples.
Click to expand...
I chose the M4 over the shotgun because it handles better, penetrates less, and carries more ammo. I am over-simplifying the "Playing" aspect in order to get an answer for why the few shells shucked came out damaged. I should have realized taking a playful tone with regard to the frequency of handling the weapon would derail the thread; lesson learned. I appreciate all the replies, I definately have my question answered.

As for the gun sitting "waiting" for its opportunity, that is not an option for me. My teenagers in the house (well trained) with a parade of their teenage friends (not trained at all). Guns go in the safe when I leave the house. Most of the clearing is done for my 14 year old; He asks to handle it and I oblige. After clearing.
 
Tirod said:
Metal magazine feed lips scratch up rounds. It's a source of friction early in their service life, one that Pmags eliminate. Otherwise the lips need to be honed down either by hand work, or by hundreds of softer brass cases wearing them down.

It's a result of being punched from steel sheet and the mag companies don't use expensive blanking dies to keep the edges nicely dressed. Stamping tends to shear and tear the edge slightly, and the problem gets worse as the dies age, same as on other parts of the gun.

Feed ramps are ground into the barrel extension and some will have sharp edges, causing scratches, too. Hand cycling rounds will make it worse compared to letting the bolt fly forward at full speed. With designed velocity from the BCG, the cartridge is less likely to have gravity pull it down into contact with the ramps as much - it flies forward rather than dragging up the ramps.

Self loading actions tend to batter the bullets slightly compared to the smoothly designed gravity influenced manual action guns. That's why you can shoot standard loads in bolt action guns but they might set back in self loaders, and why military ammo is crimped to prevent setback. Full auto does not tolerate low neck tension bullets sitting in cases.

Once fired the case is pushed against the bolt face as it extracts IF the bolt cycling speed is optimal - if overgassed for use with cheap underpowered ammo, or if improperly timed, the case is dragged out by the extractor, then the ejector tilts it to collide with the port opening where it then hits the left hand case deflector. It's basically getting banged out the opening into two possible hard objects. The HK91 series rifles can dent the cases nearly 50% of the diameter, so the AR isn't alone. A manual action rifle never sees the speeds involved and the empties are simply flipped out with contact on the ground as the major hard object.

Most self loading guns have all these issues - shoot more of them and you will see the distinctive marks of each typical of that action. It's not dialogue written for a CSI episode, it's something you can readily see with experience, same as discerning the different sounds of each firing at a short distance away. Spend time under Uncle Sam's careful tutelage and you get to shoot quite a variety - and get paid to do it. But they all share similar traits, and it has to do with getting loaded at combat speed into a chamber and then blown or jerked out for the next.
Click to expand...
This is a great post with excellent detail. I appreciate it. I am using 30 rnd window PMags exclusively, so the mag is not the issue.
 
I don't have a live bullet sitting in a chamber in any of my semi automatic firearms. It takes very little effort to pull back the charging handle, load a round from the magazine and fire for me.

I do reload 5.56 / 223 and find that many of my spent cases have a small dent when I gather them up.
I figure they hit that deflector on the way out of or some part of the ejection port.
If they are dented heavily, I discard, but a light dent just gets cleaned up, resized, trimmed and reloaded as is.
Haven't had an issue yet regarding a dented reload with feeding or function-a-bility.
 
sigsmoker said:
I don't have a live bullet sitting in a chamber in any of my semi automatic firearms. It takes very little effort to pull back the charging handle, load a round from the magazine and fire for me.

I do reload 5.56 / 223 and find that many of my spent cases have a small dent when I gather them up.
I figure they hit that deflector on the way out of or some part of the ejection port.
If they are dented heavily, I discard, but a light dent just gets cleaned up, resized, trimmed and reloaded as is.
Haven't had an issue yet regarding a dented reload with feeding or function-a-bility.
Click to expand...
I do not find this to be the case with an AR. I prefer to keep any weapon used for HD fully loaded. The charging handle on the AR is difficult for me to operate shouldered, and anything other than releasing the bolt from fully extended can hang a case up. Not sure I want to have that additional step if the weapon is ever needed in a hurry.
 
I have cycled live rounds to check cycling, cycled them out after hunting, whatever reason. I notice some scratches at times but don't worry about it and certainly don't segregate them afterward, they get put right back into the mag. If they are decently.made rounds neither the rifle nor the cycled round will ever care. The AR isn't that persnicketty or at least mine isnt.
 
Another source of scratches can be the forward edges of the barrel extension lugs. During extraction, slow or fast, the ejector presses the case to the right, against whatever is there. These scratches mainly show up in the neck area, but could be on the bullets too I guess.
 
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