805ebr Posted July 2, 2013 Share Posted July 2, 2013 Oh noes. Last time I cleaned this it was one piece. Link to comment Share on other sites More sharing options...
gerritm Posted July 2, 2013 Share Posted July 2, 2013 Call CZ CS and they will replace it. Tell them you want the new billet type piston and this should solve all your problems. They replaced my son's in about 3 days and the gun has run perfect ever since. gerritm Link to comment Share on other sites More sharing options...
goodmanac Posted July 2, 2013 Share Posted July 2, 2013 (edited) Call CZ CS and they will replace it. Tell them you want the new billet type piston and this should solve all your problems. They replaced my son's in about 3 days and the gun has run perfect ever since. gerritm I bought theirs and it didn't perform as well as the original, like at all. I have since then swapped out the CZ-USA one out for the original. The original piston cycles everything I put through it flawlessly. The CZ one turned my semi-auto shotgun into a bolt gun. Practically every other shot I had a FTF. I called them about it and they didn't seem to care to look into it, maybe I will call again. Their response was basically, "don't shoot light loads through it". Rounds going 1200fps cycle perfectly through these 712's, so for them to tell me their piston was fine kind of threw me off... The CZ piston is smaller and fits pretty loose compared to the stock piston, which is why it won't cycle lighter loads properly. Hopefully my stock piston holds up long enough for them to redesign theirs, which I hope they do. Edited July 2, 2013 by goodmanac Link to comment Share on other sites More sharing options...
gerritm Posted July 3, 2013 Share Posted July 3, 2013 The new one we got several months ago is redesigned. He broke 2 of the original pistons before getting this one under warranty. It even says billet on it. Old one was a cheap lightweight steel, always had trouble cycling low weight and low power loads, new one is heavy duty with very good rings and fits tight. Not sure which one you have, but we have run every kind one load from cheapie Wally world Federal and Winchester to Remington club loads thru his and they all work. His gun would never cycle the low power stuff and low weight loads consistently especially Fiocchi 7/8oz. reduced recoil slugs and they all work now. Gun has run 100% since the new billet piston. gerritm Link to comment Share on other sites More sharing options...
goodmanac Posted July 3, 2013 Share Posted July 3, 2013 The new one we got several months ago is redesigned. He broke 2 of the original pistons before getting this one under warranty. It even says billet on it. Old one was a cheap lightweight steel, always had trouble cycling low weight and low power loads, new one is heavy duty with very good rings and fits tight. Not sure which one you have, but we have run every kind one load from cheapie Wally world Federal and Winchester to Remington club loads thru his and they all work. His gun would never cycle the low power stuff and low weight loads consistently especially Fiocchi 7/8oz. reduced recoil slugs and they all work now. Gun has run 100% since the new billet piston. gerritm Did yall get the factory redesign or the CZ-USA design(it's stamped 'CZ-USA')? My 712 is a 2013 I believe, based on what the guys at CZ were telling me, the 2013's have a factory redesigned gas piston(the one the factory does in Turkey). The new gens can cycle low recoil loads now it seems and I think the stock piston is stronger than the older gens too. The guy I spoke with on the phone said if it works just run with it, I'll keep the CZ-USA one as a backup for now since it doesn't fit tight or cycle the same low recoil loads. Link to comment Share on other sites More sharing options...
Aleric Posted July 4, 2013 Share Posted July 4, 2013 (edited) Greetings! Long time listener first time caller. Just picked up a 28 inch 712 ALS yesterday. stripped it down last night and gentle lubed it. locked the bolt open over night. on my way out to family farm to shoot it. taking 00 buck and federal 71/2 1200 fps loads and Winchester 71/2 1145 loads to break it in. the full choke is in the barrel. Will let you know how it goes. Happy 4th America Edited July 4, 2013 by Aleric Link to comment Share on other sites More sharing options...
Aleric Posted July 4, 2013 Share Posted July 4, 2013 We got back a little while ago I realized that I didn't actually hit send to post my above reply. The good news is that I fired 50 rounds of various ammo with out a single issue! All were 2 3/4 inch. the first 40 were for function. the first 5 rounds of those were Federal Premium high brass 1 1/4 shot #5 traveling at 1400fps. these start to get your attention. ejection was forward and to the right. they were ejected with some authority! each of these ejected hulls had a dent in the brass near the area where it meets the plastic hull. The next thirty rounds were Federal Field and Target 1 1/8oz #7 1/2 with a posted 1145 fps on the box. these landed within 5 feet from the gun but reliability was %100. the remaining 15 were Winchester USA Target and Field Loads with 1 1/8 oz. #8 shot traveling at 1200pfs according to the box. A few Winchester Universal 7 1/2 shot with unknown velocity and weight of shot were mixed in with these. again the gun was %100 with my 10 and 12 year old sons shooting the gun along with me. I was impressed. Now its time to put a extended tube on it and get ready for three gun Link to comment Share on other sites More sharing options...
goodmanac Posted July 8, 2013 Share Posted July 8, 2013 Any good news on those bolt handles Zfields? Link to comment Share on other sites More sharing options...
805ebr Posted July 9, 2013 Share Posted July 9, 2013 I got the replacement piston in the mail today. It appears to be billet but is not stamped as such. It is engraved with CZ-USA. I'm eager to test it out. It appears to fit tightly, so hopefully it'll work fine. The o-ring they sent me is way too big. I've yet to get the correct one from them. Either they don't ship, or send one that is way too big. Lol. Oh yeah, and.. Any good news on those bolt handles Zfields? Link to comment Share on other sites More sharing options...
goodmanac Posted July 9, 2013 Share Posted July 9, 2013 I got the replacement piston in the mail today. It appears to be billet but is not stamped as such. It is engraved with CZ-USA. I'm eager to test it out. It appears to fit tightly, so hopefully it'll work fine. The o-ring they sent me is way too big. I've yet to get the correct one from them. Either they don't ship, or send one that is way too big. Lol. How curious, mine fits so damn loose, I wonder if I can just ship it back for a new one. Or I'll just run the original since it ain't broke, and I can run that until it gives up haha. Link to comment Share on other sites More sharing options...
goodmanac Posted July 11, 2013 Share Posted July 11, 2013 Have you gotten to test your new piston 805ebr? With 1200 FPS 2 3/4 loads specifically. Link to comment Share on other sites More sharing options...
zfields Posted July 12, 2013 Share Posted July 12, 2013 Any good news on those bolt handles Zfields? Working on it! Been slammed the last couple weeks dealing with starting a new LLC. SItting down and ammending the cad drawings to send over right now. Sorry everyone! Link to comment Share on other sites More sharing options...
usmc90 Posted July 12, 2013 Share Posted July 12, 2013 Any good news on those bolt handles Zfields? Working on it! Been slammed the last couple weeks dealing with starting a new LLC. SItting down and ammending the cad drawings to send over right now. Sorry everyone! Np ! But speaking for us all i'm sure , Thank you for the update Link to comment Share on other sites More sharing options...
805ebr Posted July 12, 2013 Share Posted July 12, 2013 (edited) Have you gotten to test your new piston 805ebr? With 1200 FPS 2 3/4 loads specifically. I did! I tested with 100 rounds today. 50 rounds Federal Target Load 2 3/4 DRAM, 1 1/8oz shot, #8 1145 fps 25 rounds Remington Gun Club Loads 1 1/8 oz shot, #7.5 1200 fps 10 rounds Fiocchi LE slug, 7/8oz, low recoil, 1300fps 10 rounds Fiocchi LE 00 Buckshot, 9 pellets, 1150 fps 5 rounds Federal 00 Buckshot, Flight Control, reduced recoil, no additional info The only issue I had was one Fiocchi buckshot round that failed to fully extract from the chamber. Other than that it ran just awesome. There is a small local match this weekend where I will run approx the same round count. I am not going to clean it prior to the match, and will let you know if there are any issues. Hope this info helps. When I do break it down to clean it after this weekend, I plan to take the calipers to the magazine tube and piston. Maybe contributing this info will help determine why your piston is so loose? Edited July 12, 2013 by 805ebr Link to comment Share on other sites More sharing options...
goodmanac Posted July 12, 2013 Share Posted July 12, 2013 Have you gotten to test your new piston 805ebr? With 1200 FPS 2 3/4 loads specifically. I did! I tested with 100 rounds today. 50 rounds Federal Target Load 2 3/4 DRAM, 1 1/8oz shot, #8 1145 fps 25 rounds Remington Gun Club Loads 1 1/8 oz shot, #7.5 1200 fps 10 rounds Fiocchi LE slug, 7/8oz, low recoil, 1300fps 10 rounds Fiocchi LE 00 Buckshot, 9 pellets, 1150 fps 5 rounds Federal 00 Buckshot, Flight Control, reduced recoil, no additional info The only issue I had was one Fiocchi buckshot round that failed to fully extract from the chamber. Other than that it ran just awesome. There is a small local match this weekend where I will run approx the same round count. I am not going to clean it prior to the match, and will let you know if there are any issues. Hope this info helps. When I do break it down to clean it after this weekend, I plan to take the calipers to the magazine tube and piston. Maybe contributing this info will help determine why your piston is so loose? Thank you! That would be great, I'll have to measure mine. If it does have a smaller diameter I will be sending it back to CZ-USA and request a replacement of equal dimensions. Thanks for the update Z! Link to comment Share on other sites More sharing options...
805ebr Posted July 15, 2013 Share Posted July 15, 2013 I ran a small local match match yesterday. 93 rounds Federal Field and Target (Walmart bulk pack), 3 DRAM, 1 1/8oz shot, #7.5, 1200fps 10 rounds Fiocchi LE slug, 7/8oz, low recoil, 1300fps 2 rounds Fiocchi LE 00 Buckshot, 9 pellets, 1150 fps I had issues with 6 - 10 rounds of birdshot short stroking. The round would get out of the chamber okay, but hang up on ejection (basically stovepipe). So that kinda sucked. I haven't pulled the gun apart yet but I have a few hypothesis. I had to reuse the o-ring since CZ sent me was the wrong one with the piston. I think there may be a gas leak as my o-ring is pretty trashed. Not running the gun wet enough. I used minimal lube when I re-assembled with new piston. Perhaps the piston needs additional break in We'll see when I take it apart what I can determine. And I'll also measure out some parts. Link to comment Share on other sites More sharing options...
goodmanac Posted July 15, 2013 Share Posted July 15, 2013 I ran a small local match match yesterday. 93 rounds Federal Field and Target (Walmart bulk pack), 3 DRAM, 1 1/8oz shot, #7.5, 1200fps 10 rounds Fiocchi LE slug, 7/8oz, low recoil, 1300fps 2 rounds Fiocchi LE 00 Buckshot, 9 pellets, 1150 fps I had issues with 6 - 10 rounds of birdshot short stroking. The round would get out of the chamber okay, but hang up on ejection (basically stovepipe). So that kinda sucked. I haven't pulled the gun apart yet but I have a few hypothesis. I had to reuse the o-ring since CZ sent me was the wrong one with the piston. I think there may be a gas leak as my o-ring is pretty trashed. Not running the gun wet enough. I used minimal lube when I re-assembled with new piston. Perhaps the piston needs additional break in We'll see when I take it apart what I can determine. And I'll also measure out some parts. Sounds similar to my issues but mine would eject the spent hull fine and then it wouldn't fully load the next shell. So I would either have to push the bolt forward, or eject it and start over if it seemed stuck. Never had any ejection issues, just a lot of FTF's. Thanks for the update! Link to comment Share on other sites More sharing options...
805ebr Posted July 16, 2013 Share Posted July 16, 2013 (edited) Admittedly this is pretty unscientific, but it's the tools I had available. Scale and calipers (I think bore gauge is correct tool for this?). I averaged the caliper readings as I took readings at multiple places in an attempt to get some semblance of accuracy. O.D. of my mag tube 1.004" Old piston 1.51oz 1.005 ID at the bottom of the piston "lip" 1.024 ID where it opens up after the bottom lip New piston 1.55oz 1.005 ID at the bottom of the piston "lip" 1.027 ID where it opens up after the bottom lip So the new piston is 3 thousandths bigger. Honestly I find it slides more smoothly with less resistance on the mag tube. There is no slop for the fit up for mine. The other pictures I've included are regarding trying to diagnose my fail to eject/short stroking issue. When I pulled the gun apart the piston was sitting cocked. It appears it was not fully seating against the o-ring. The other picture shows the build up of junk where the piston should be fully seated. My best guess is that not getting a good seal, gas was blowing out of this area instead of pushing against the piston, and this was causing my issue. Since my o-ring is beat, and I have yet to be able to get the correct one from CZ (3 attempts), I'm on a mission to try and source replacements and replace each time I clean cleaned whether needed or not. Seems like cheap insurance. If anyone knows what o-ring material I should be looking at (viton, buna, etc.) please let me know. Edited July 16, 2013 by 805ebr Link to comment Share on other sites More sharing options...
goodmanac Posted July 16, 2013 Share Posted July 16, 2013 (edited) Admittedly this is pretty unscientific, but it's the tools I had available. Scale and calipers (I think bore gauge is correct tool for this?). I averaged the caliper readings as I took readings at multiple places in an attempt to get some semblance of accuracy. O.D. of my mag tube 1.004" Old piston 1.51oz 1.005 ID at the bottom of the piston "lip" 1.024 ID where it opens up after the bottom lip New piston 1.55oz 1.005 ID at the bottom of the piston "lip" 1.027 ID where it opens up after the bottom lip So the new piston is 3 thousandths bigger. Honestly I find it slides more smoothly with less resistance on the mag tube. There is no slop for the fit up for mine. The other pictures I've included are regarding trying to diagnose my fail to eject/short stroking issue. When I pulled the gun apart the piston was sitting cocked. It appears it was not fully seating against the o-ring. The other picture shows the build up of junk where the piston should be fully seated. My best guess is that not getting a good seal, gas was blowing out of this area instead of pushing against the piston, and this was causing my issue. Since my o-ring is beat, and I have yet to be able to get the correct one from CZ (3 attempts), I'm on a mission to try and source replacements and replace each time I clean cleaned whether needed or not. Seems like cheap insurance. If anyone knows what o-ring material I should be looking at (viton, buna, etc.) please let me know. Well I just looked at my CZ piston and they do look very similar, so I'll take the exact Measurements tomorrow. I have a feeling they'll be the same. I wonder if your piston seat is a different size then mine. And I think you may be right, that puppy is dirty! A good cleaning should fix a few things. I can also tell you right now that our internals are different. My spring is black and must be coated with something. My O-ring is internal and seated within the barrel ring where the piston sits. The bolt carrier rail that compresses the spring on the tube is also different; mine is black and may be a different material. With all of these differences I suspect our original pistons may also be of different design. Here is a picture of my two pistons: Edited July 16, 2013 by goodmanac Link to comment Share on other sites More sharing options...
goodmanac Posted July 17, 2013 Share Posted July 17, 2013 ID of the top is 25mm (0.98 in). ID of the bottom (couldn't get in between interior lips due to lame calipers) is 25mm (0.98 in). OD of the top edge/ top lip is 26.6mm (1.05 in). OD of the area with the O-rings is 30.2mm (1.19 in). OD of the bottom edge/bottom lip is 31.8mm (1.25 in). So, it appears the pistons are slightly different, if we are measuring the same dimensions that it. I would be interested to see what your OD is for the o-ring area, since that's the one that determines if the piston sits tight or loose. Link to comment Share on other sites More sharing options...
zfields Posted July 18, 2013 Share Posted July 18, 2013 Changes sent over to the machinist. Link to comment Share on other sites More sharing options...
goodmanac Posted July 19, 2013 Share Posted July 19, 2013 (edited) Changes sent over to the machinist. Exciting! I'm still waiting on ATI for my stock, so that paired with your bolt handles is going to look great. Edited July 19, 2013 by goodmanac Link to comment Share on other sites More sharing options...
RDF5186 Posted July 19, 2013 Share Posted July 19, 2013 Looks good. Link to comment Share on other sites More sharing options...
hacksaw556 Posted July 19, 2013 Share Posted July 19, 2013 (edited) Just take my money already zfields! Edited July 19, 2013 by hacksaw556 Link to comment Share on other sites More sharing options...
goodmanac Posted July 19, 2013 Share Posted July 19, 2013 Just take my money already zfields! Haha for real, burning holes in my wallet here Link to comment Share on other sites More sharing options...
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