New CZ 97B jamming - Page 2

buddyd157 · July 15, 2020, 09:50 AM

you should have tried shooting the gun, after the grinding down of the lock, to see if that was the problem, which i think it was not. you did 2 operations, the grinding down of the lock, and polishing of the ramp. frankly, you are not really certain which operation made any corrections.

if you go and send back that lock for a replacement, they very well may deny one under warranty.

i think if anything, polishing the ramp may have been all that you needed.

it is also highly possible that there was some "crud" on the ramp, from the factory, when they did test firing of the gun.

also possible that carbon got built up real quick, if the ammo you used was "dirty" firing?

**Mal H** · July 15, 2020, 10:16 AM

I tried to get as clear a photo as I could. Where your point of the triangle appears to be right in the center, mine is off-center and to the rear. The flat face is parallel to the bullet path when it is installed in the gun. I tried to get a photo of that, but it's practically impossible to get a macro shot of it and light it well enough to show the slide lock.

Guggmeister · July 15, 2020, 10:42 AM

Mine had the same problem on last round.
Filed the slide release tab shorter sideways.

Sent from my iPhone using Tapatalk Pro

hemiram · July 16, 2020, 02:58 AM

I don't have my 97B anymore, but it was kind of touchy about ammo when it was new, maybe the first couple of hundred rounds. By the time it was eating all the FMJ stuff I had without any problems, I started putting JHP stuff through it and only a friend's reloaded rounds upset it. Factory loads were fine. I honestly liked the gun, but I liked my EAA Witness .45 better, and it shot anything I put in it from round 1.

Skans · July 17, 2020, 08:17 AM

What bothers me is that the casting marks on the inside of the part look rough and not finished.

Moloch · July 21, 2020, 05:05 PM

So, I polished the feed ramp some more, disassembled the magazines and cleaned and lubed the insides and polished the chamber as well.

I put some chrome polish onto a spent 45ACP case, put the case into my stationary drill and then I put the barrel over the case very slowly, with a back and forth motion. (

) I only did this for a couple seconds. Now the chamber is much shinier. I also put a rag on a wooden dowel and using the same polish, polished the ''ceiling'' of the chamber where the projectiles drag on when they're stuffed into the chamber, to a mirror finish.

Today I shot a couple hundred more rounds through it, so far it shot 300 rounds of commercial Fiocchi 230 grain FMJ ball without a single hiccup.

It still does not like my short OAL 220 grain lead round nose loads, BUT when I increased the OAL of the cartridge from 1.228 to 1.263, the OAL of the Fiocchi commercial load, and slightly upped the load (VN340, from 6.3 to 6.6 grains / 900 fp/s) it shot 45 rounds without a malfunction.

Unfortunately I'm gonna have to decrease the load a bit, I'm getting primer drag and I rather lose a couple fps and go easy on the firing pin. Apparently 220 grain at 900 is a bit on the hot side. -

I also shot hot 230 grain XTP loads through it, they worked just fine.

July 15, 2020, 09:50 AM	#26
buddyd157 Member Join Date: April 14, 2020 Location: New England Posts: 40	you should have tried shooting the gun, after the grinding down of the lock, to see if that was the problem, which i think it was not. you did 2 operations, the grinding down of the lock, and polishing of the ramp. frankly, you are not really certain which operation made any corrections. if you go and send back that lock for a replacement, they very well may deny one under warranty. i think if anything, polishing the ramp may have been all that you needed. it is also highly possible that there was some "crud" on the ramp, from the factory, when they did test firing of the gun. also possible that carbon got built up real quick, if the ammo you used was "dirty" firing?

July 15, 2020, 10:42 AM	#28
Guggmeister Senior Member Join Date: March 10, 2013 Posts: 117	Mine had the same problem on last round. Filed the slide release tab shorter sideways. Sent from my iPhone using Tapatalk Pro

July 16, 2020, 02:58 AM	#29
hemiram Senior Member Join Date: November 6, 2005 Location: Toledo, ohio Posts: 762	I don't have my 97B anymore, but it was kind of touchy about ammo when it was new, maybe the first couple of hundred rounds. By the time it was eating all the FMJ stuff I had without any problems, I started putting JHP stuff through it and only a friend's reloaded rounds upset it. Factory loads were fine. I honestly liked the gun, but I liked my EAA Witness .45 better, and it shot anything I put in it from round 1.

July 17, 2020, 08:17 AM	#30
Skans Senior Member Join Date: November 20, 2008 Posts: 11,132	What bothers me is that the casting marks on the inside of the part look rough and not finished.

July 21, 2020, 05:05 PM	#31
Moloch Senior Member Join Date: November 27, 2005 Posts: 1,419	So, I polished the feed ramp some more, disassembled the magazines and cleaned and lubed the insides and polished the chamber as well. I put some chrome polish onto a spent 45ACP case, put the case into my stationary drill and then I put the barrel over the case very slowly, with a back and forth motion. ( ) I only did this for a couple seconds. Now the chamber is much shinier. I also put a rag on a wooden dowel and using the same polish, polished the ''ceiling'' of the chamber where the projectiles drag on when they're stuffed into the chamber, to a mirror finish. Today I shot a couple hundred more rounds through it, so far it shot 300 rounds of commercial Fiocchi 230 grain FMJ ball without a single hiccup. It still does not like my short OAL 220 grain lead round nose loads, BUT when I increased the OAL of the cartridge from 1.228 to 1.263, the OAL of the Fiocchi commercial load, and slightly upped the load (VN340, from 6.3 to 6.6 grains / 900 fp/s) it shot 45 rounds without a malfunction. Unfortunately I'm gonna have to decrease the load a bit, I'm getting primer drag and I rather lose a couple fps and go easy on the firing pin. Apparently 220 grain at 900 is a bit on the hot side. - I also shot hot 230 grain XTP loads through it, they worked just fine.