Bulged barrel in new CZ527 carbine 7.62x39
Bought a new unfired CZ527 carbine, ser # A552x and while cleaning the bore prior to firing it the first time, I discovered a bulge in the barrel 14" from the muzzle and about 3/4" long. Can't tell how overbore the bulge is but you sure can tell it with a patch and jag. This position is right at the rear sight boss. Returned it to CZ-Kansas City and they sent ser # B824x as a replacement. You guessed it, the replacement has a bulge at the same location. I am presently awaiting an answer to my letter to the factory in the Czech Republic. CZ-Kansas City has also sent a letter to the factory. If you have one of these carbines, I would highly recommend that you run a tight patch through the bore from the muzzle and feel for the bulge. If you run a patch through from the breech I don't think you can sense the bulge. Sincerely, single popper[:(][:(][:(]
onepopper
onepopper
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Can you visually see the bulge? They usually show as a dark ring in the barrel.
Rafter-S0 -
Interesting. I have a CZ 527 carbine in 7.62X39 in the A3000 serial number range (a couple of thousand lower than your first CZ) and the barrel is perfect. Sounds like you are having a run of bad luck!
Mark T. Christian0 -
Maybe they were test fired with oil or grease in the barrels at the factory or proof house. 0 -
Well there are bulges and rings (smaller form of bulge, no?).... I havne't seen a BULGED barrel from firing with oil in the barrel, but have seen ringed barrels.... now I don't advocate firing either, but that said I have fired ringed barrels, no trouble, with light loads.
"...hit your enemy in the belly, and kick him when he is down, and boil his prisoners in oil- if you take any- and torture his women and children. Then people will keep clear of you..." -Admiral of the Fleet Lord Fisher, speaking at the Hague Peace Conf0 -
Could not see the bulge with a very strong bore light. No black rings or any other indications other than the patch sliding through the bulge, this was very apparent. I have fired other firearms with bulges in the barrel with no problems or loss of accuracy. But tell me, how many of us would be satisfied with a bulged barrel on a newly purchased firearm? Sincerely, onepopper [V]
onepopper0 -
Send it back to them. 
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onepopper,
Since I can't actually handle and work with your rifle, any of what I propose is just a guess.
I don't think that what you are feeling is a bulge or a ring. I think what you are being sensitive to is the site island area of the hammer forged barrel. In order to get the site island, a ring must be left all the way around the outside of the barrel. In a separate machining step, all of the ring is removed from the O.D. of the barrel except for what is needed for the site base. Hammer forged barrels have huge amounts of stress built up within them simply from the process. When an area is machined after the forging, the steel in that area will be slightly relieved or it will relax, if that makes more sense. It gets just a tiny (and I do mean tiny) bit bigger in the bore/groove area. It is so tiny that you can't see it with your bore light but quite possibly can feel a subtle difference with a very tight patch. Another way to get a an idea of where and what it is would be to air gage the barrel. That's probably out of the question though since very few barrel makers air gage any more and the equipment is far too expensive for a gunsmith to purchase for the rare use it would get.
Just another way to look at the question.
Best of luck!0 -
Why are you cleaning from the muzzle end in the first place.
I'm not trying to be a wise guy, but if that is the way you
feeling it, then you must be cleaning that way.I own many CZ rifles,
and have been so impressed with the out of the box accuracy.
Teach them young ! Teach them often !
God bless America!0 -
quote:Originally posted by juddroy
Why are you cleaning from the muzzle end in the first place.
I'm not trying to be a wise guy, but if that is the way you
feeling it, then you must be cleaning that way.I own many CZ rifles,
and have been so impressed with the out of the box accuracy.
Teach them young ! Teach them often !
God bless America!
Typically running a cleaning rod in from the muzzle is the only way to get one down the barrel. Kinda hard to do it from the breach unless you remove the barrel from the reciever. Unless it's a bolt action and you remove the bolt.0 -
It is a bolt gun.That is why I said that about cleaning from the muzzle.
Teach them young ! Teach them often !
God bless America!0 -
Do you know how to remove the bolt?
JM0 -
juddroy, these are unfired rifles. When possible, I always clean from the breach. In this case, a new rifle, I clean from both the breach and the muzzle. I shoot many differant calibered Martini rifles and clean from the muzzle as many Martinis are difficult to disassemble. I also shoot MI Garand, that is cleaned from the muzzle. Of course I use care, but also use Dewey rods and brass jags. Years ago, I was issued a Navy National Match 7.62 Garand. After firing this rifle thousands of rounds in practice and matches, I placed 2nd in an All Navy Leg Match. My 600yd score was 198-6x, a new range record.
bgjohn, I know how to remove the bolt. Sincerely, one popper
onepopper0
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