How often does THIS happen?

Buckaroo8

Well-Known Member
A few questions for all you ammo experts out there....
Took the .243 rifle for a walk yesterday and put a few federal factory rounds (100gr Sierra Gameking BTSP) through to practise/check zero and when I came to pick up empties I noticed this cartridge had split quite badly.....how often does this happen? what causes it and can it affect the accuracy of the bullet?
IMG_5855.jpg
I also noticed a difference in bullet seating depth between two batches of ammo. Is this common?
IMG_5857.jpg

Cheers
 
I always use Federal brass to reload for my .243. I have loaded many hundreds, perhaps several thousand rounds but have never had a case split so far. In the past I used Federal 100gr factory ammo without a split.
Cannot help with variation in seating depth with factory ammo.
 
Just happend to notice this with my factory ammo the other day. It was 55gr 222 sako game head and there was a fair difference that was easily noticeable by the eye. Ddnt seen to make much difference as they were all spot on a 100 yards.
 
Probably the brass is brittle because it hasn't been annealed properly.
 
A few questions for all you ammo experts out there....
Took the .243 rifle for a walk yesterday and put a few federal factory rounds (100gr Sierra Gameking BTSP) through to practise/check zero and when I came to pick up empties I noticed this cartridge had split quite badly.....how often does this happen? what causes it and can it affect the accuracy of the bullet?
View attachment 24358
I also noticed a difference in bullet seating depth between two batches of ammo. Is this common?
View attachment 24359

Cheers
I've got hundreds of cases like that,mainly remy,25-06 and 30-06 eats the cases,some split around the other way too just up from the rim
 
looking at the picture the soft points look too blunt any chance they have been dropped or have they just been from mag to chamber a lot !
 
They all look like that straight out of the box. The tips probably look worse in the zoomed in picture than they do in real life but I remember being offered a box of winchester .243 ammo in a gunshop once and found that the tips were all p1ssed as hell.... I didn't buy them purely because they looked wrong. These federal rounds seem to be more accurate in my rifle than any other factory ammo I have tested and the bullet seating depth doesn't seem to make any difference to zero or accuracy.
Thanks for your replies chaps
 
It's possible for seating depths to change under recoil if the cartridge has been in the magazine a time or two while other rounds have been fired. I'm not saying that's happened in this particular case, but recoil can certainly generate seating depth changes that may interfere with accuracy and pressure......even under certain conditions affecting pressure in a dangerous way.
ATB
 
Probably the brass is brittle because it hasn't been annealed properly.

factory loads are not loaded as a home loader would seat a bullet ie by a set of vernier calipers and Bullet comparator this seating problem can be due to seating bullet by a machine buy the hundreds an hour just a small tip on lead/other will push a head back at that speed of loading, so thats why your homes loads are normly better than factory for your rifle most factory use a bullet with a crimping cannula .
As to the split case problems not every factory agrees on how much thay should or should not case anneal so we get hard and soft brass .i found this on the net may explain why better.
The useful life of a cartridge case usually ends with an excessively expanded primer pocket or a split neck, and several factors can determine the number of firings it will withstand before calling it quits.
When a case reaches the final step in its forming process at the factory, work-hardening has made the brass quite hard over its entire length. The head of the case is left that way for strength, but its neck and shoulder are annealed to make them softer and more elastic.
If you bend a wire coat hanger back and forth repeatedly, it will eventually break at that point because it has lost its elasticity. That’s work-hardening. The same thing happens when a cartridge is fired and then reloaded: Its neck expands away from the bullet, and sizing it back to its original diameter during the reloading process causes it to become harder—just like the coat hanger.
Expand and resize the neck often enough and it will eventually lose its elasticity and split. Softening the necks of cases by annealing as required will prevent this from happening.


Read more: http://www.rifleshootermag.com/2012...hat-affect-cartridge-case-life/#ixzz2Jv4SdLP3
 
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factory loads are not loaded as a home loader would seat a bullet ie by a set of vernier calipers and Bullet comparator this seating problem can be due to seating bullet by a machine buy the hundreds an hour just a small tip on lead/other will push a head back at that speed of loading, so thats why your homes loads are normly better than factory for your rifle most factory use a bullet with a crimping cannula .

Not a seating problem, lack of understanding regarding production methods.
Also about the 'crimping cannelure' - used generally to hold / bond the lead core.


Definition of 'Cannula';

A cannula (from Latin "little reed"; plural cannulae) or canula is a tube that can be inserted into the body, often for the delivery or removal of fluid or for the gathering of data. In simple terms, a cannula can surround the inner or outer surfaces of a trocar needle thus extending needle approach to a vein by half or more of the length of the introducer.
 
so sorry for spelling incorrecty

Cannelures can be used for crimping grooves, for identification of certain bullet weights or designs, or (applied to the case) as a method of preventing a bullet from being pushed back into the case during the feeding cycle. This is especially effective on cartridges that headspace on the end of the case.
Definition of CANNELURE

1
: a groove running lengthwise on the surface of a cylinder or column

2
a: a groove around the cylinder of an elongated bullet for small arms to contain a lubricant
b: a groove around a bullet into which the edge of the cartridge case is crimped
c: a groove around the rotating band of a gun projectile to lessen the resistance offered to the rifling
d: a groove around the base of a cartridge where the extractor takes hold

and or this

Cannelures in Lead Bullets: primarily to hold Lube, with one groove to crimp the case mouth. Also to reduce bullet- rifling contact, and thus reduce leading.

Cannelures in jacketed bullets...

A. in Military (FMJ) bullets: to Lock core to jacket to prevent shedding.
to allow for proper mouth crimp to hold bullet in place ( or for neck stab-crimp in some WW I and
WW II ammo)
to lock in a tracer capsule ( second cannelure)

B. in Sporting ammo: To lock jacket in place, allowing for controlled expansion but retaining rear-end mass
To crimp bullet into neck of case.


:tiphat:
 
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so sorry for spelling incorrecty

Cannelures can be used for crimping grooves, for identification of certain bullet weights or designs, or (applied to the case) as a method of preventing a bullet from being pushed back into the case during the feeding cycle. This is especially effective on cartridges that headspace on the end of the case.
Definition of CANNELURE

1
: a groove running lengthwise on the surface of a cylinder or column

2
a: a groove around the cylinder of an elongated bullet for small arms to contain a lubricant
b: a groove around a bullet into which the edge of the cartridge case is crimped
c: a groove around the rotating band of a gun projectile to lessen the resistance offered to the rifling
d: a groove around the base of a cartridge where the extractor takes hold

:tiphat:

No problems, no need for any apology.
It helps everybody if the correct nomenclature is used in the long run.

You may find that your crimp groove applies to straight wall cases more often than not. Generally not applicable as a seat depth gauge on rifle ammo.
 
yup and think you got me wrong mty i never said thay were a seating depth gage only that a lot of ammo makers put them on the bullets the the reasions given in my last see sec 2 #b


:tiphat:
 
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I noticed this cartridge had split quite badly.....how often does this happen? what causes it and can it affect the accuracy of the bullet?

The case neck was brittle. It shouldn't be, but it was, so it couldn't stretch normally. It won't affect accuracy to any measurable extent.

I also noticed a difference in bullet seating depth between two batches of ammo. Is this common?

Yes, it's common. They've been battered about in transit, or in your rifle's magazine (probably the former as the 243 isn't heavy recoiling). It won't affect accuracy to any significant extent for deer stalking at anything less than 200 yards - I presume you're stalking roe and taking heart/lung shots. You can in fact use a blade or similar tool to 'repair' the tip if you wanted as it's just soft lead.

-JMS
 
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