Cases getting stuck in chamber

farnorthdan · April 14, 2008, 11:42 AM

So I shot some of my reloaded 9mm in my CZ75 this weekend and had a number of cases getting stuck in the chamber, which required a take down and barrel removal to pry the cases out.

I've never had this problem before with these loads????

I'm looking for possible causes of this problem. any suggestions are appreciated.

wncchester · April 14, 2008, 12:07 PM

Well, you don't say if they are fired or unfired.

There is only one thing that can cause unfired cartridges to stick in the chamber and that is they are too big. If they chambered easily and are fired and stick, the cases are still too big. Usually from excess pressure.

MaineColt · April 14, 2008, 01:25 PM

Are these factory or reloads??

**Unclenick** · April 14, 2008, 02:14 PM

MaineColt,

Reread his first sentence. He tells you.

Farnorthdan,

As Wmccjester said, if this jam happened during feeding, you've either got cases that are not crimped from the expander flare or they are too long and are jamming in the throat.

If there is an extraction failure when firing, the pressure is way over the safe limit in your gun. You are in danger of bursting through the case brass, and should be able to measure that on the extracted brass. In the latter case, be aware of the danger of seating bullets too deep, or of failing to crimp well enough to prevent recoil from pushing the bullets deeper into the case while they are still in the magazine.

A lot of manuals base powder charge only on bullet weight. That is something you can often get away with in a bottleneck rifle case where bullet seating depth doesn't displace a high percentage of the powder space under it, and where the powder is slow enough to get the bullet going down the barrel and opening up space behind it before the peak is reached. In a short, nearly straight case, the percent volume decreases rapidly as the bullet goes deeper. Since pistol powder is relatively quick and peak pressure is dependent on the volume the powder is burning in, that can have a dramatic effect. I've got a pressure test barrel for .45 ACP, and have seen just 1/8" deeper bullet seating raise a load from about 17,000 PSI to about 23,000 PSI. If I had started with the load nearer the maximum for the cartridge (21,000 PSI) it would have been pushed uncomfortably higher.

Nick

farnorthdan · April 14, 2008, 03:39 PM

Nick, thanks for the informative advice. I am still at a loss as to why these cases are getting stuck. I've loaded about 4k rounds with this particular recipe and have not encountered this problem before. I guess I'll put this lot to the side until I can figure it out; I really don't want blow up my CZ, its one of my favorites.

JDG · April 14, 2008, 03:47 PM

What is the load your having trouble with?

DIXIEDOG · April 14, 2008, 06:51 PM

Dirty chamber?

Sigma 40 Blaster · April 14, 2008, 08:13 PM

If you're still using the same charge and bullets with the same OAL you probably need to crimp a little more to knock all of your case flare out.

Take your calipers and place them about 1/2" below the case mouth, move them up to the case mouth. You should have not to adjust your calipers to move them up past the mouth of the case. I usually crimp mine to knock the flare out +.001 or .002.

Alaskee · April 15, 2008, 01:06 AM

CZs are notorious for having short throats. Check the O.A.L. on those rounds as opposed to a similar bullet profile that chambers and ejects easily. If possible, seat one of the bullets a little deeper and see what happens.

April 14, 2008, 11:42 AM	#1
farnorthdan Senior Member Join Date: December 3, 2007 Posts: 371	Cases getting stuck in chamber So I shot some of my reloaded 9mm in my CZ75 this weekend and had a number of cases getting stuck in the chamber, which required a take down and barrel removal to pry the cases out. I've never had this problem before with these loads???? I'm looking for possible causes of this problem. any suggestions are appreciated. __________________ Believe NONE of what you hear; HALF of what you see and ALL you believe Accuracy is king,penatration is queen but why not jack'em in the process if you can.

April 14, 2008, 02:14 PM	#4
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	MaineColt, Reread his first sentence. He tells you. Farnorthdan, As Wmccjester said, if this jam happened during feeding, you've either got cases that are not crimped from the expander flare or they are too long and are jamming in the throat. If there is an extraction failure when firing, the pressure is way over the safe limit in your gun. You are in danger of bursting through the case brass, and should be able to measure that on the extracted brass. In the latter case, be aware of the danger of seating bullets too deep, or of failing to crimp well enough to prevent recoil from pushing the bullets deeper into the case while they are still in the magazine. A lot of manuals base powder charge only on bullet weight. That is something you can often get away with in a bottleneck rifle case where bullet seating depth doesn't displace a high percentage of the powder space under it, and where the powder is slow enough to get the bullet going down the barrel and opening up space behind it before the peak is reached. In a short, nearly straight case, the percent volume decreases rapidly as the bullet goes deeper. Since pistol powder is relatively quick and peak pressure is dependent on the volume the powder is burning in, that can have a dramatic effect. I've got a pressure test barrel for .45 ACP, and have seen just 1/8" deeper bullet seating raise a load from about 17,000 PSI to about 23,000 PSI. If I had started with the load nearer the maximum for the cartridge (21,000 PSI) it would have been pushed uncomfortably higher. Nick __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

April 14, 2008, 03:39 PM	#5
farnorthdan Senior Member Join Date: December 3, 2007 Posts: 371	thanks for reply Nick, thanks for the informative advice. I am still at a loss as to why these cases are getting stuck. I've loaded about 4k rounds with this particular recipe and have not encountered this problem before. I guess I'll put this lot to the side until I can figure it out; I really don't want blow up my CZ, its one of my favorites. __________________ Believe NONE of what you hear; HALF of what you see and ALL you believe Accuracy is king,penatration is queen but why not jack'em in the process if you can.

April 15, 2008, 01:06 AM	#9
Alaskee Senior Member Join Date: August 25, 2002 Location: Nelchina Alaska Posts: 131	O.A.L. CZs are notorious for having short throats. Check the O.A.L. on those rounds as opposed to a similar bullet profile that chambers and ejects easily. If possible, seat one of the bullets a little deeper and see what happens.

April 14, 2008, 12:07 PM	#2
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	Well, you don't say if they are fired or unfired. There is only one thing that can cause unfired cartridges to stick in the chamber and that is they are too big. If they chambered easily and are fired and stick, the cases are still too big. Usually from excess pressure.

April 14, 2008, 01:25 PM	#3
MaineColt Senior Member Join Date: November 2, 2007 Location: Maine Posts: 222	Are these factory or reloads??

April 14, 2008, 03:47 PM	#6
JDG Senior Member Join Date: November 28, 2005 Location: West Michigan Posts: 673	What is the load your having trouble with?

April 14, 2008, 06:51 PM	#7
DIXIEDOG Senior Member Join Date: June 12, 2007 Location: Maine Posts: 265	Dirty chamber?

April 14, 2008, 08:13 PM	#8
Sigma 40 Blaster Senior Member Join Date: July 1, 2007 Location: East Texas Posts: 997	If you're still using the same charge and bullets with the same OAL you probably need to crimp a little more to knock all of your case flare out. Take your calipers and place them about 1/2" below the case mouth, move them up to the case mouth. You should have not to adjust your calipers to move them up past the mouth of the case. I usually crimp mine to knock the flare out +.001 or .002.