View Full Version : Pinged Cases and Accuarcy
My LMT MWS really pings cases pretty hard. I've mitigated this by adding a Velcro strip (loop not hook) to the shell deflector.
The one on the right is typical for what happens when the case hits the shell deflector without the Velcro strip I have added.
The one on the left is dented but not really evident in the pic. Still dented.
http://i830.photobucket.com/albums/zz229/Scoby/308brass_zpsec626d99.jpg (http://s830.photobucket.com/user/Scoby/media/308brass_zpsec626d99.jpg.html)
I've shot Federal ammo that was dented before just as range ammo and never worried about it. What would be the effect on precision reloads with the dented brass?
Anyone have any experience with this?
Unless you're shooting benchrest I doubt it would make any real difference. I would think it would take some serious and extensive testing to actually come to some valid conclusion. Time, energy and money most guys are not willing to invest, I know I'm not. For me, I like my reloads to look good, a big body dent would cause me to reject that case.
goodoleboy
01-12-14, 04:46
To reinforce what has already been said, I would reject that case anyway. If you were to reload it, I don't think it would be dangerous, at least not the first time. Over time, fire forming that general area of your cases would, in theory, lead to shorter case life. Annealing your bass might make a difference.
With regards to accuracy, inconsistent case dimensions would hurt the potential accuracy of your shots (ie from a bench). Hammering rounds at steel or paper off-handed, you probably wouldn't notice. From a bench, inconsistent geometry in the case would lead to variations of pressure when firing. Pressure variations lead to vertical strings. If these dents affect the alignment of bullets in the throat by causing a concentricity/runout issue, then each round would be different. This would have to be checked with a concentricity gauge at the mouth of the case.
You may even find that the dent weakens the case to the point of case wall collapse during reloading, but in a small case like a 5.56/.223, that it is doubtful, especially considering the type of dent you are dealing with.
From what I see on the case fired after Velcro, I wouldn't hesitate to reload it for training or plinking purposes.
I wouldn't hesitate to reload either of those cases.
That kind of dent is totally meaningless.
Agree with Bimmer, those case are absolutely fine. I load far, far worse, and guess what? They shoot just fine. Hell, one of my rifle is a 223AI, so every time I fire a 223 in it, it moves far, far more brass than dents far worse that. I could care less what my reloads look like, the result downrange is much more important.
I wouldn't hesitate to reload either of those cases.
That kind of dent is totally meaningless.
This.
With regards to accuracy, inconsistent case dimensions would hurt the potential accuracy of your shots (ie from a bench). Hammering rounds at steel or paper off-handed, you probably wouldn't notice. From a bench, inconsistent geometry in the case would lead to variations of pressure when firing. Pressure variations lead to vertical strings. If these dents affect the alignment of bullets in the throat by causing a concentricity/runout issue, then each round would be different. This would have to be checked with a concentricity gauge at the mouth of the case.
I'm not concerned with the safety aspect of firing the cases with the dents.
My concern lies with the possibility of inconsistent accuracy of the reloaded rounds.
Reloading is all about consistency and some of these cases are dented more that others, hence inconsistent volume. Case volume does effect pressure and can/does effect the POI. But, how much? I can live with a .25 MOA variation to keep from ditching a bunch of cases but not much more than that.
I was curious as to whether or not anyone had any personal experience with this. Components are hard to find now days and wanted to see if anyone could save me the pain and expense of going through the motions. Not to mention these little dents driving my OCD nuts.
TO be honest, I would be surprised if there was any noticeable accuracy difference. Case capacity plays a role, but brass will grow to the capacity of the chamber regardless, and brass is so fluid that I would wager that while the difference is real, it is most likely inconsequential. When one gets into the minutiae of reloading, chasing rabbits is very often the outcome. Unless one is chasing tenths for a benchrest title, good enough is very often good enough.
Those dents aren't going to impact accuracy.
Those dents aren't going to impact accuracy.
I'm hoping not. I have a good bit of it that looks like the pic.
Going to load up 20-30 rds and see how they print. It's still going to irritate my OCD.
It's still going to irritate my OCD.
That's OK, as long as you realize that it's only you being OCD, and it doesn't have any real significance...
Me thinks you might not have enough stress in the rest of your life, if this is really going to bug you.
I won't lose sleep over it. It's just going to take some getting use to I suppose.
Reloaded for bolt guns all my life and never had this come up before.
If you would like to O or C about something, please let it be that if you cull those cases that the new cases you replace them with will be violently ejected, as all spent cases from gas guns are treated harshly. A self loading rifle puts firepower above accuracy. No free lunch.
Reloaded for bolt guns all my life and never had this come up before.
I meant to say before: This is how semi-autos abuse brass.
Your dents and my AR aren't so bad... M14's extractor puts a noticeable divot in every cartridge rim, my Glock allows the famous "Glock bulge," and a friend's Makarov utterly destroys .380ACP brass.
If they really, really bug you, then I'll take 'em off your hands. They're worth 5¢/case to me, which should easily cover shipping.
I would have thought the dent like such would cause a weakness in case. Good read for sure
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I would have thought the dent like such would cause a weakness in case. Good read for sure
Brass will work harden from swaging, shaping, etc. This is a good thing for the case head on brass, but a bad thing for the shoulder and neck. Annealing will return brass necks and shoulders to a softer state.
That said... I don't anneal 223 ever. I just don't have any problems with 223 brass, even if dented. On 30 cal (308 and 300WM), I can feel uneven neck tension when seating bullets. I anneal those every time.
Thanks, this is extremely helpful for me personally as I'm about to begin to reload.
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I was able to put a few of these dinged cases down the tube. Doesn't seem to have affected much if anything. Did quite well actually.
What did surprise me a little is that the dings did not fire form out much, if any, like I thought they would.
Oh.. they fire formed out completely.... assuming you didn't have some subsonic creme puff load.
You just got new dings. There aint NO WAY a brass ding can stand up to 50k PSI or whatever that load is yielding.
Mark the old dings with a Sharpie. The marks won't be over the new dings..;)
Right again Mark.
It was late in the day when I fired these rounds and didn't thoroughly inspect them until now. I was just seeing dents again and to the level that they were before firing and putting the Velcro on the shell deflector. Apparently in depends on how the case hits the deflector/Velcro as to how bad the dent is.
No cream puff load. 43.3 grains of IMR 4064. Right at max. according to the Sierra manual. No pressure sign as of yet. It hasn't been above 50 deg. when I've fired any of these loads. This summer might change things.
Here is a pic, excuse my pic skills, of a case were the old "ping" was located. Looking back, it probably was more of a gouge than a "ping". It did form out but, not all the way. It's very minimal and hard to see in the crappy pic but it's still there. If you look closely, right where the case body meets the shoulder, a split is present or starting to form. This is just above where the old "ping" was located.
http://i830.photobucket.com/albums/zz229/Scoby/OldDent_zpsa907f294.jpg (http://s830.photobucket.com/user/Scoby/media/OldDent_zpsa907f294.jpg.html)
This case is toast.
Here is a pic of the new "dent" in the same case. This LMT is brutal on brass.
http://i830.photobucket.com/albums/zz229/Scoby/NewDent_zps09b26030.jpg (http://s830.photobucket.com/user/Scoby/media/NewDent_zps09b26030.jpg.html)
Yeah... we didn't use Lapua brass in Pappabear's LMT because it's just a little rough on brass. Nature of the beast and easy to get over... because the LMT did everything else so damned good.
Also... Pappabear's LMT like 4064 too. We run Varget for bolt gun .308
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