Mystery dent...?

[RemingtonAI]

Did some shooting this weekend and when I was doing brass prep today I noticed this little dent on 3 out of 45 cases. It's a bolt action in .308 and I have never seen this on any cases in the past. I did drop a couple cases which I believe is the most likely cause.
My question is...1, do any of you think it is something else other than a dent from possibly being dropped on concrete? And 2, since I have now FLS sized them (bumping the shoulder .002) should I toss em? Can it hurt the rifle? I figured it would fire form out, if it wasn't a bad idea to try it that is.
Thanks for the help in advance! Jesse

 

[rvn1968]

It looks like excess case lube. IMHO Tom.

 

[M-61]

Do not be concerned with that dent if that is the only thing you see. Fire it and it will be gone.

 

[Ggmac]

Well it happened after it fired so don't worry about it !

 

[RemingtonAI]

Definitely not excessive case lube, although I wondered the same thing. Only reason I am sure is because I spend so much time with each round in my hand while reloading due to my overly obsessive nature, I would have seen it for sure. Every round was measured with the RCBS Precision Mic from base to datum after sizing, as well as base to ogive after seating...every one.
Ok great, sounds like they are good to go then. They'll get a back x on em and we'll see what happens down range for the sake of science next time. Thanks a bunch guys. Jesse

 

[ireload2]

That was probably caused by your ejector. You pulled the bolt back at just the right speed to slam the case into the locking abutment inside the receiver. The factories should break the inside corners to stop that. That happens a lot with the large shoulder of a .243 and .308. The same brand of rifle will not do that with a .223 or 6mm Rem because the shoulders are smaller.

 

[RemingtonAI]

That was probably caused by your ejector. You pulled the bolt back at just the right speed to slam the case into the locking abutment inside the receiver. The factories should break the inside corners to stop that. That happens a lot with the large shoulder of a .243 and .308. The same brand of rifle will not do that with a .223 or 6mm Rem because the shoulders are smaller.

ok, that makes sense. If that was the case, what is the solution? Should I still reload these few? Any side effects of continuing to do this and reloading the casings? Thanks

 

[JohnKielly]

Not saying this is the reason, but one time when I was belly shooting I ended up with 3-4 cases with a neat little ewlbow joint mark on the from the piece of grass that must have blown in the chamber.

 

[dickn52]

Your ejection pulled the case rearwards and it hit the back of the port. Very common on semi's as well. Especially the older HK91 series before they put the rubber bumper on them.

 

[ireload2]

Go ahead and reload them but - do not put any lube in the area of the dent or it might get worse when sized. Once fired it will disappear.

To correct the problem
1. Pull the bolt open slowly and watch the ejector snap the case to the right. Then pull back at different speeds to see if you can reproduce the condition that causes the dent. I have a .222 that mashes the case mouth a little if I open the bolt slowly so I cut a coil off of the spring. You might have to doctor your ejector spring too or just pull the bolt open faster or slower.

I had several .243s that I cured by deburring inside the receiver on the top corner when I had the barrels off. It is hard to reach with the barrel on it but you might get at it with a stone. I also have a 6mm Rem. It does not hang on the shoulder but if it is opened fast the cases will flip out spinning and hit the receiver and the stock just ahead of the bolt handle. The .25-06 picks up nicks on the shoulder and my 30-06 does not seem to do anything. I also have an Egyptian Hakim 8x57 autoloader. It puts big dents in 3 or 4 different places on the brass and it varies a lot from case to case. Some of the dents are over 1/4" long and .010 deep. I reload them and they blow out the next time the case is fired.

ok, that makes sense. If that was the case, what is the solution? Should I still reload these few? Any side effects of continuing to do this and reloading the casings? Thanks

 

[243winxb]

Pressure getting past the neck may put a dent in that area, if using starting loads of the slowest burn rate powders. Dent not seen in a 308 yet? Happens with large magnums and is not common. Produces extra soot. A longer than normal OAL can add to the problem, letting the bullet move sooner than normal.

 

[billlarson]

It looks like excess case lube. IMHO Tom.

+2

 

[RemingtonAI]

Well, I Guess I will just keep track of it. I honestly don't think it is excess case lube because 1 I would have seen the dents for sure without a doubt, and 2 when I just reloaded them I tried more lube and did not get the dent. Also, I don't think the case is hitting the receiver since I cant seem to recreate the dent when ejecting rounds here at the house. I have reloaded around 800 rounds for this rifle so far and it hadn't done it in the past. I also do a thing where I bring the bolt back with the back of my thumb, then when the case is ejected ill just snap my hand forward and catch it mid air and set it down in the box so I don't have anything to clean up.
The one difference in my shooting condition was rain. I was shooting in a thunderstorm and even though I had a roof over me, it was starting to blow in and get me and my gear wet. I was thinking the rounds may have gotten a drop of water on them which may have caused the dent when fired? Very likely they did get a little wet because I was completely soaked after evaluating my paper target 300 yrds downrange in the middle of a lightning storm. Pretty sketchy conditions for a golf cart ride. Guess I'll have to keep an eye on it. Jesse

 

[Shynloco]

It's lube that wasn't removed. Wipe them a bit more next time and shoot 'em. Been there done that myself.

Alex

 

[Archer]

Definitely not excessive case lube, although I wondered the same thing. Only reason I am sure is because I spend so much time with each round in my hand while reloading due to my overly obsessive nature, I would have seen it for sure. Every round was measured with the RCBS Precision Mic from base to datum after sizing, as well as base to ogive after seating...every one.
Ok great, sounds like they are good to go then. They'll get a back x on em and we'll see what happens down range for the sake of science next time. Thanks a bunch guys. Jesse

This is basic reloading 101...look for the pictures in any reloading manual under the section for lubing the case...Clean your die, lube has plugged the vent hole in the die which then causes this to happen when you size the case because the air has nowhere to go. Use a paper clip to clean the hole.

 

[MGYSGT]

It's not that you put too much lube on the cartridge. It's just that the lube builds up in the die. Clean out the die by shooting some break cleaner or carb cleaner into the die. Then give it a light lube with some Q Tips before using again.

 

[Shaggy357]

The photo does not show the type, nor size, of a dent worthy of concern. IMHO. You can put your black X on it before firing, but doubt if you see any difference between that fired case and all the other fired cases, excepting the X. Little dent like that is often cause for bringing out the brake cleaner and giving the sizing die a good cleaning. A little extra lube or a minute piece of polishing media is all it take to make a little dent like that. Again, not worthy of worry in my opinion.

Steve

 

[RemingtonAI]

I do appreciate the great responses from you guys. However unfortunately I will have to reiterate that this was not done while sizing. See above comments for details but basically, I was trying to say that we can rule out the possibility of the dent being there before I fired the case. This is because I meticulously inspect each case while doing many probably unnecessary steps including but not limited to, measuring CBTO and base to datum point after resizing and seating each round. I also just so happened to check for runout on the hornady concentricity gauge for each and every round in this batch, so I most certainly would have seen the dents during one of, if not during all of those steps. My dies are also meticulously clean and inspected each time I use them.
However, Shynloco's comment is entirely possible since it involved the dent happening while or after firing/ejecting. I wish this was the case but unfortunately that's not it either. I did not mention as it was not pertinent until now, but before primers or bullets are seated they are re-tumbled to get brass shavings out of the casing from trimming and chamfering. At this time the lube left on the inside and outside of the casing is for all practical purposes removed. Therefore I don't think it could be from lube left on the case while firing.
I really do appreciate the comments because even if it doesn't ultimately solve the issue I do learn from them, even if its just learning more about something I already knew. I'm still stumped on the dent but my suspicions still lie with the possibility of rain getting on the round before being fired, and maybe aliens...who knows. Thanks again guys. Jesse

 

[RemingtonAI]

A little extra lube or a minute piece of polishing media is all it take to make a little dent like that. Again, not worthy of worry in my opinion.

Steve

Oh, I didn't see where you mentioned a piece of polishing media. I suppose that could be it if it will cause that type of dent. I do use a nylon brush on the inside of the casing after tumbling but hey, how can you really be sure right? I will keep that in mind and try to do some more rigorous brushing next time to see if I get any cases where more ended up coming out. Thanks. Jesse

 

[Clavius-Walker]

Not saying this is the reason, but one time when I was belly shooting I ended up with 3-4 cases with a neat little ewlbow joint mark on the from the piece of grass that must have blown in the chamber.

I've had this happen also.