Dented Cases and Rough Exposed Lead Tips - Accuracy Concerns

[147 Grain]

Question from a non-reloader:

Do dented cases or rough looking exposed lead tips on factory ammo affect accuracy?

[147 Grain]

Also, concerning a bullet's seating depth:

With factory ammo (I've inspected) using crimped canaller bullets, often 1/3'rd of a box will be crimpted at the bottom of canaller, 1/3'rd crimped right in the middle, and the other 1/3'rd near the top of the canaller.

How does this change accuracy?

[147 Grain]

Finally:
 
Can some of you experts please recommend how to inspect and sort factory ammo?

Perhaps there's a way to use one group for hunting, another for target shooting, and another for plinking or whatever.

Thank-you in advance of your replies!
 
Steve

[Hunterbug]

I do not shoot anything with a dented case. Period. As for buggered tips, yes it may effect accuracy but not enough that most shooters can tell with most rifles. A competition shooter could probably tell but not most people. Seating depth can effect accuracy, most people like to be pretty close to the lands, like .030" or so for optimum accuracy. The differences that you are talking about probably won't matter much. I'll let someone else get the third question as I try to avoid shooting factory ammo so I don't know much about it.

[Alboy]

I would attack it as making the next step from where you have taken it.
 
In your weapon, sorted by depth of seating fire some groups and see if your style/weapon/ammo combination make any difference in the POI (point of impact) and/or group size. Then fire a group with one of each depth and see how tight that group is.
 
Decide for your self what is acceptable.
 
Dented cases will chage the combustion chamber some what and could effect the pressure spikes thus accuracy. Then again folks fire form new cases for wildcats from existing ammo all the time. It is a judgement call on how comfortable you are with the dent in question. Minor or major.
 
If the dent is creased or has a hard sholder line I would scrap it. The line could provide a place for heat to concentrate and cause a case failure.
 
There was an article or information some time back where research was done on deformed bullet points and accuracy. I will try to research it, some one here may know it off hand. Seems accuracy for the average shooting situation was not overly affected. Like a deer sized target at 100 yards or so.

[gitano]

Dented cases - No harm, do as you wish especially on factory ammo and ones you aren't going to reload. I've shot some cartridges that I had to physically "adjust" just to get in the chamber. For the most part, the case is just a place to hold powder.
 
Sorting factory ammo - I'd go with Alboy's comments on that one, but I'd also ask, "If you're going to go to all that trouble, why not just reload?"
 
Deformed noses - This comment will undoubtedly deform some noses - Actual experimental data has repeatedly demonstrated that severely mangled noses do not measureably affect Point of Impact for hunting cartridges. I have not seen a 'benchrest' test. I suspect too many BRs would faint at the mere mention of deforming a bullet's nose. :D
 
Interestingly, I have recently been thinking about this subject again due to all of the casting I have been doing. So... in the name of "science" and just plain orneryness because I hate voodoo, I'm gonna repeat the bullet nose deformation experiements that I have seen published. I intend to seriously deform the noses of both cast and jacketed bullets. We'll see what the results are. THL will be the first to know.
 
Paul

[Alboy]

Youngin Paul
 
Glad to here of the pending info avalanche. Thought I had heard that out of you but was not sure enough to use your name.
 
I am still going to send those 340's one day. When I get a new addressing ink pen and both of these hands out of the cast.

[gitano]

pending info avalanche

No fair! You know me too well. :D
 

both of these hands out of the cast.

Yikes! What's up with that?
 
Paul

[M1Garand]

Deformed noses - This comment will undoubtedly deform some noses - Actual experimental data has repeatedly demonstrated that severely mangled noses do not measureably affect Point of Impact for hunting cartridges. I have not seen a 'benchrest' test. I suspect too many BRs would faint at the mere mention of deforming a bullet's nose.

I couldn't agree with you more and was going to add the same thing. If we were striving for groups to close by 1/8" then it may have some influence but for hunting, they're fine. I shot some Sierra Game Kings with the lead tips deformed and was just using them for practice and they shot as good as the new ones out of the box I had loaded for hunting. They sure didn't move point of impact any.

[Alboy]

Do not let me spook you Paul. That is slang excuse around these parts for not gettin around to things that should have already been finished.

[m gardner]

Dents don't seem to hurt anything. I've dented cases from useing too much case lube at times and there didn't seem to be any serious side effects. If there are small grooves they seem okay. Dents from rough handling have been alright(like closing the bolt on one that's jammed, or short stroking the bolt). You can't stop a wilderness hunt to get more ammo so I've used it with no ill effects. The only sorting I've noticed that amounted to anything was rolling the cartridges on a flat plate or in a v block. If the bullet wobbles alot they won't shoot as well, but most are plenty good enough for hunting. I've noticed no problems with accuracy if the tips are damaged, though I've rolled them concentric again on a rock or metal of the rifle. Like what's been said, learn to reload. God bless and good hunting.

[gitano]

Do not let me spook you Paul. That is slang excuse around these parts for not gettin around to things that should have already been finished.

Whew! I was worried a bit. I just broke my collar bone (in half!) and thought maybe there was something "going around" :D
 
Glad to hear there isn't.
 
Paul

[Alboy]

Well sorry to hear that. The 45-70 or Colath prove too much? You need a little more grwoing before tackling those big guns?
 
Or did mama take exception with you and show you the error of your ways.
 
There is also the possiblility that you are trying to keep up with the teenagers in your life and learning what is meant by old man. That education cost me dearly.

[CAfrica]

I find that experience of differring seating depths in factory ammo strange.  i would be more likely to accept that the apparent difference is cause by differences in case lenth and not in seating depth.
 
Take a couple of the ones that differ the most and measure OAL.  See if the difference is repeated.  If not, those differences are case related and not seating depth.
 
On the issue of nose damage, I agree with Gitano (and others) it makes little difference.  The interesting thing is that damage to the base of the bullet does have an effect (but then you will only know this if you handloaded the bullets).
 
C

[gitano]

I agree with CAfrica regarding OAL. It could also be slight variations in bullet Quality Control as well. I have measured some manufacturers bullet for OAL to nominal caliber, and found them quite variable (up to 7 thousandths or so), as compared to other manufacturer's. Barnes (all of them) and Nosler Partitions were the worst I measured. That was some time ago, and I suspect QC is better these days - especially for Nosler. Regardless, cartridge OAL is likely pretty consistent, but in order to measure it accurately, you'll have to move down the bullet ogive away from the tip. Unless the bullet is a hollow point or full metal jacket, variability in the amount of deformation of the exposed lead nose will confound efforts to get accurate OAL measurements. Stoney Point's hardware is excellent for this excercise.
 

There is also the possiblility that you are trying to keep up with the teenagers in your life and learning what is meant by old man.

Stabbing at a ground ball going by first base. :) (I did catch it though. :D )
 
Paul