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ringer
10-05-2008, 02:42 AM
Bulged cases
I have just noticed that the fired cases from my CZ 453 .22 lr have a bulge just above the rim about 90 degrees around the case as per these pictures


http://i516.photobucket.com/albums/u322/db1961/PA050072.jpg

Anyone have an idea what would cause this?

bagul
10-05-2008, 06:26 AM
do you mean to say... bulge on top of the casing,adjusent to the rim? ...looks to me like your chamber entrance has a large chamfer. But i'm wondering why the chamfer is only on top of the chamber? if the round does not chamber fully, the casing would also bulge but i suppose it will bulge the entire circumference, not jusy 90 degrees on top. does it shoot great?

DonMatzeder
10-05-2008, 06:46 AM
Looks to me like someone has ramped the chamber so it will feed better. Pull a case carefully and see if the bulge is at the bottom. If it is not at the bottom, it's just a sloppy chamber.

Larry Willis
10-05-2008, 07:19 AM
It looks like the bulge goes around the case. I've seen this before, and it was caused by a buildup of lead just in front of the chamber. The rifle was a tight chambered Ruger 10-22, and the rounds were firing before they were in full battery position. You need to resolve this problem right away, because the next shot could blow the rim off your case and cause an injury.

The buildup of lead is not always easy to see without a borescope.

- Innovative

KEN HARPER
10-05-2008, 07:48 AM
Great picture!

BrentD
10-06-2008, 06:13 AM
It is the extractor cut. The extractor is a bit short.

At least that is what happens on my rifle. Not sure that it really matters much so long as it does not cause a burst case.

Brent

John Kielly
10-06-2008, 06:32 AM
It looks like my old Stevens with the under barrel magazine. It was so worn out when my dad bought it for me that the headspace was shot. One of his friends built up the back of the root of the bolt handle (the lockup) so it took the slop out.

Ah, the rifles we shot, the clapped out cars we drove, the deaths we somehow avoided ..... :cool:

ringer
10-06-2008, 07:28 AM
Gents
Thank you very much for your input. I wouldnít normally worry but it is shooting like a dog at the moment.
Looks like it may be either:
1. A sloppy chamber.
2. A build up of lead; or
3. Bad headspace.
Iíll give the chamber a good clean with a bronze brush to eliminate the possibility of lead build up and if that doesnít fix the problem Iíll get my smith to check the headspace.
Iíll let you know how it goes. Thanks again.