Case cracks or indents?

R

rklapp

New member
I've used these cases three times in my MN 91/30. I'm not sure if the cases are cracked or if they become indented when extracting from the chamber. Obviously, they are compromised. I've shot thousands of rounds with surplus ammo but never noticed the indents, but this could be because of the old Russian cases. I also haven't noticed the indents on any of the two previous times I used the brass. Just wonder what your opinion is. TIA

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Definitely a scratch or and indent. Interesting for sure. Can identify if its hitting something whilst expracting? They didnt have the marks before they were shot right?
Any chance a peice of brass wire or something is the the chamber? It could mark the case when it expands upon being fired.
 
The markings seam to have similar shape but moving as mentioned in the chamber.
Chamber pressure indenting with a metal sliver then moved.

Have the cases recently been trimmed and when chamfered?

A shaving might have released from the mouth and remained in the chamber.

I am calling these cases because they don't look like brass. The material could be causing the problem.

Were the cartages transported in a clean container?
 
I shot 40 rounds and these were the only three. I would think if there was an extrusion in the chamber, it would happen more often... or not. I guess it's possible that a foreign material was in the chamber then worked it's way out. I only noticed it because I reload.
 
I shot 40 rounds and these were the only three. I would think if there was an extrusion in the chamber, it would happen more often... or not. I guess it's possible that a foreign material was in the chamber then worked it's way out. I only noticed it because I reload.
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I do not know, I do not know how much powder you are using and I do what powder you are using and I do not know how loose the bore is and I do not know how well the bullet fits the bore.

But if what happened to your cases happened to my cases I would suspect something is moving very slowly; like, the case is not expanding and sealing the chamber before pressure inside the case seals the chamber. When that happens to my cases the case collapse from the outside in, there are times the case rips, the rip allows the gas to escape and like magic the case flattens out giving the case the appearance of having been hit with a shaped charge. This happens with Turkish ammo; remember, Turkish ammo can be 70 years old.

Anyhow, I would shine a light into the split to determine if what you are looking at is a crease or a cut in the case, you can also place a hose of the neck of the case and then place the case in water. After placing the case in water force air into the hose and look for bubbles.

F. Guffey
 
Being mark is the same on all the cases but its moved on the cases Id put a dollar that something was in the chamber and either worked its way out the breach or was carried down the muzzle and is now gone forever.
 
Whether there was something in the chamber(possibly a bit of cleaning brush. Probably in the barrel and came back.) is really irrelevant. Those cases are toast. Really isn't worth worrying about 3 empties.
Do a visual inspection of the neck of the one and a bent paper clip 'feeler gauge' with the other two to be sure anyway.
 
Good advice everyone. I don't feel anything using the paper clip so I'm still going with the foreign object in the breach theory. Probably from the cleaning brush as you mention. I give the breach a more thorough inspection and keep my eye out for any more scratches.
 
Just my cases: My cases are embeddable, I like that, If something gets between the chamber and case when I pull the trigger and if that something has weight and takes up space it gets embedded into the case.

Don't put a lot of effort into it but I suggest you at least fill one of the cases with water.

Shooters have checked their cases after firing there a have been times shooter/reloaders have found the neck missing; not on the first case but on the last case. And then there are those that have cases come apart; nothing before, no warning and then suddenly and all at once. The same story starts with a liken-un to: It handled like a doll buggy right up to the time it came apart.

F. Guffey
 
That's a tough one. I'm at least inclined to think that the brass had defects that split it when it stretched, but it does look as if pieces of junk were in the chamber. Dunno.
 
More drama at the range...
The first round I put into the breech didn't go in smoothly, so I pulled the bolt back and it pulled the casing off the bullet spilling powder all over the inside. This is the second time this has happened out of about 200 rounds. I got the bullet out with a rod and cleaned out most of the powder I could. I didn't have any more "cracked" cases but I was getting "dents". These started going away after 30 rounds. The cases below are the PPU. The heavier Win cases have barely noticeable dents but this could be because I was shooting them later. Hard to tell. Looking into the barrel, I don't see (or feel) anything out of the ordinary in the bore. I don't crimp the bullet since I can't seem to find a Lee crimper on Amazon Prime.

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I bought a caliper last week and discovered I was over trimming. The 54r cases should be 2.114 in and instead averaged 2.107 in. The overall length should be 3.037 in and instead were about 3.020 in, so it's unlikely that they were too long and could reach the lands and grooves. I'm using a .312 bullet 150 grains which gives the neck a slightly noticeable (insignificant?) dent on one side when I seat the bullet. I plan to order a .311 from Graf since I'm having trouble finding one from my local dealers. Despite the initial set back, I was rather happy with the results.

50 yards with 1x reddot scope.
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Did those dents happen before or after you fired? It looks like a lube dent from using too much lube on the neck and shoulder.
 
They do look like resizing dents but I'm positive that these occurred after firing the round.

I have a choice to make. Do I seat the bullet .125" to make the recommended 3.037" overall length or do I seat to .250" to the connelure and make the round shorter than it should be?
 
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If the rifling is occasionally grabbing the bullets when you eject a live round then yes I think you should probably seat shorter. Don't necessarily have to go to the cannelure unless you want to crimp them. I rarely pay much attention to book OAL on rifle rounds, I load them to fit the rifle. Usually to fit the magazine or at least .025 off the rifling - whichever is shorter (unless I'm single loading and using bullets that are picky about seating depth)
 
The first photo shows cases with what appears to be flaws in the brass, A lot of brass is cheap and this shows up after a few reloads, shooting and reloading has exposed the flaws....don't reload these.

The second photo shows incipient case separations on the far left and center case. Not the lube dent on the shoulder, that's no problem....That line right below the shoulder , next firing and the case could separate.
It happens from firing and resizing , military rifles are generously chambered , the sizing die brings the brass back to factory specs. The more you work the brass the sooner they wear out. This is common in military rifles. I had a Model 95 Mauser in 7x57 that after 3 reloads that little line would show up, only by using a neck sizing die could I extend the life of the cases. My Mauser developed the line in the exact same spot.

Get some new quality brass and adjust your sizing die to size a fired case just enough to allow the bolt to close, no more , and see if this helps.
You could also try a neck sizing die and this would allow reloading without resizing the case body, extending case life.
Gary
 
Is there any difference in accuracy for having a round that is .125" shorter than OAL?
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Shorter OAL also does not necessarily make the round less accurate; in fact with most of the loads I've taken the time to try differing OALs there was not usually a significant difference (if any). Sometimes they even shoot better with a longer jump. It depends largely on the nose profile of the bullet and the individual chamber. When it does it's most often bullets with a secant ogive shape (long nose VLD type mainly); they tend to shoot better close to the lands. Most common hunting bullets are of tangent ogive design and are usually pretty tolerant of distance to the lands. As always it depends on the individual rifle and specific bullet but that's been my most common experience.

Another point - 3.037 is the SAAMI maximum OAL per Lyman #50, but that does not make it the correct OAL for all sizes and shapes of bullets. The book OAL for the Hornady 150gr SP #3120 for instance is 2.870 - not sure exactly which bullet you're using but 3.020 possibly could be too long for that bullet in your rifle. It depends on the exact shape of the nose and where the full diameter of the bullet starts. I actually pay very little attention to what the book says for OAL; instead I establish my own for the specific bullet I'm using in my own chamber. Sometimes the limit is magazine length rather than distance from the lands.
 
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