Tuning Taipan 700mm CZ Barrel Owners - Thumbs Up / Thumbs Down?

[jdanvers]

I bought one for my Taipan Long. I also purchased a power plenum and installed both at the same time. In case it isn't obvious - intent *was* to be able to get more power out of it and chuck heavier slugs.

So far I'm quite frustrated with it. I've heard rumor about one disturbing thing - barrels landing on peoples doors steps that aren't quite straight. (?) The packaging that mine was in was beat to hell when it did finally show up. I'm about to pull it off and roll it around on a flat counter top to check and see if it is in fact straight.

Here's the thing though - it DOES shoot *some* ammo fantastically. 18g jsb pellets. 20g nsa slugs. 22 gr fx hybrids. 23g nsa slugs. 23 gr h&n slugs. ( all .217 )

↑ . . . . and that's where it stops. The first time I try to go above 23g the damn thing turns into a shotgun. I zero at 40 yards. All of the above shoot 5 shot 3/4" groups easily all day without my even trying to be deliberate and shoot pinhead accurate. If I try and be super steady and really accurate - the 23g nsa's win hands down - 5 shot dime size is very doable ( and has been done ). They shoot amazingly well out of this setup.

I step it up in weight to the 25.39g jsb knockouts - I'm lucky if it'll group 2 or even 3" at that same 40 yards. And yes - I'm burning through a ton of air and ammo trying multiple speeds shooting over my chrony looking for that, so far, elusive combo that might work. 27g's, 30g's. etc . . . . *anything* heavier than 23g and it goes to hell. I've tried both .217 & .218's - although I've actually given up on the latter - they've proven to be far worse (for real) than the .217's. The .217's that it likes - it *REALLY* likes them - those 23g nsa's for instance.

But c'mon . . . I could chuck the 23g's no problem with the shorter stock LW barrel and no power plenum just as well. I got the longer barrel and plenum to shoot bigger and heavier. The only big thing I'm getting so far is a headache and frustration. ;-(

So - subject asks it for those of you who have purchased one and are (trying?) to use it - how you making out??

If you are in fact making out well with it - I'm *ALL EARS* and ready to listen to any setup advice you can offer. ( what's your reg set at, what ammo, what speed, etc . . . . )

Thanks guys . . .

 

[airgunmike56]

If i was you I would send it back and ask for another one, Somethings not right.

Mike

 

[Odoyle]

I would keep the most accurate barrel permanently mounted on the gun and only shoot that one most accurate pellet and leave things alone and buy another gun for the next venture.

The only way to force the barrel to like a slug is to make your own and experiment such as buying the Corbin press and many dies like Nielsen does then you just simply make your custom taylored specific slugs for your gun only in whatever size weight and style you want to experiment with. No longer have to spend money and pray they shoot good in any of your guns. Initial cost may seem high but the extreme long distance accuracy you get is unbelievable once you get the recipe combination right. All you do is to simply buy the ingredients (dies) and experiment size, weight, length, nose, tails etc. You be shooting 200+ yards in no time and post your consistent 1/2 inch (or better) groups at 100 yards. Thank me later...

Once you set a gun to shoot a specific ammo perfect never touch it again and just shoot that most accurate pellet or slug only and enjoy it. Need another challenge buy another gun to tinker with and leave perfect boring accurate guns alone.

 

[mtnGhost]

I have reassembled Taipans hundreds of times, I'll chime in with some insight for anyone that has a new 700mm CZ. 

When I got my new Long with the 550mm CZ, I took it apart to clean / inspect / polish the bore. When I reassembled it, I noticed the orientation to the air cylinder was off a little. I knew the barrel was straight having checked it on my v-blocks. So I looked at the threading, and it was also straight and concentric.

I noticed that the threads / pitch looked a little thinner than the threads that I have made numerous times by hand for my FX barrel adapters. I reinstalled the barrel into the block again, but this time I applied a bit more torque instead of just using the milled wrench flats as a visual cue. The barrel was then seated perfectly straight.

The bottom line is they're machined in a way where it's CRITICAL that you torque it down all the way into the block. If it's not torqued all the way, then the barrel will not be seated perfectly straight and concentric. Now if you were to torque the trigger housing caps over the barrel and air cylinder when the barrel was not seated all the way - you run the risk of warping the barrel. 

Next, the bore diameter is tighter than most 22 cal airgun barrels. Mine was 5.48mm, and now it's just under 5.485 after polishing. The off the shelf variety of slugs, up to ~25gr in .217 will shoot fine. Anything larger, and you're going to want to use a smaller diameter OR something with less friction (like the MP cast ammo or the Altaros slugs).

As for me, I have not had much time to play around with this new Vet/barrel, but it shoots the .217 / 24.8gr NSAs better than anything else that I have shot them with. They're like a perfect match at 950fps, and it's pretty amazing to see a projectile with a mediocre BC perform so perfectly as they do.

 

[jdanvers]

Progress . . . . and thanks to those of you who have chimed in.

Re-reading through just now - @mtnghost - I heeded your words re: make sure barrel is tightened down into the block. I stripped it apart - again - and thoroughly cleaned and re-lubed everything prior to re-assembly. When I re-installed the barrel I actually wrapped the threads with yellow thread tape and then after threading it back into the block tightened it as best as I could with a 13mm wrench. "As best I could" meaning just holding the block in one hand and tightening the barrel, via wrench, with the other. Perhaps I should put the block into a vice or something and give it a little more torque? Regardless - it is most definitely tighter now then it was prior.

So . . . after chores around the house - re-assemble the gun and go off to the range to see if any difference. I grab a couple of tins of different ammo's that I'd like to try out - not really sure how long I'll be able to stay there though - it was only (barely) 40* with a bit of a breeze - not terribly warm. Cutting to the chase - better. Still not good though - not by any stretch of the imagination. I did have an interesting, and purely accidental, observation though.

Two of the tins I brought with me were the JSB Kock Out's @25.39g. One tin @ .216 - the other the recently purchased .217's. I was shooting the .217's as, so far anyway - up to .23g - thats what this barrel seems to like. But as mentioned in the previous couple of sentences above - no joy - I tried 5 shot groups from mid 880's up through 940 and they just would not group consistently well at all - at 40 yards. I had just started into a 930's speed test and had forgotten to check the gauge to see how much air I still had. You know where this is going - speeds started coming down as I was shooting over the chrony and I noticed that a couple of shots *did* manage to hit the paper pretty close to one another as the speeds dropped into the low 900's - which was puzzling in itself. ( lol ... I was like - " . . . didn't I just dial the hammer on this thing to get me into the 930's??" ) I realized what was happening - cursed to / at myself - gassed the gun back up and it went right back up to the 930's where I though it should have been. Shots were still scattered and unacceptable.

@odoyle - this is where you come in re: another post of mine where you told me to just hang on to all purchased ammo as I might need it for the next gun purchase. Remember that one?

I'm approaching being frustrated again as I just can't seem to get this damned thing to shoot anything over 23g in .217. I'm eyeballing that other tin of the .216's - I accidentally purchased those when I was using the original LW barrel - it didn't like them but LOVES damned near anything in .217. "What have I got to lose . . . " I mumble to myself - may as well give 'em a go and see what happens.

. . . . . . . pew. Whoa. pew! What? pew! pew! What?! What!? Are you kidding me . . . .?? 906 (avg) and these *are working* - like - they're friggin' grouping - pretty well too. No friggin' way!!! My hands are freezing by now but I load up another magazine with these .216's and grab a splatter sticker and walk it out onto the piece of paper I've been using. I walk back to the table and just shoot two over the chrony to make sure I'm not on crack - 908 / 906 - ok. Let's see if I can hit this thing.

I'm going to test with these .216's again tomorrow - maybe speed 'em up to 910 - 915 and see if they'll tighten up. Shrug shoulders - shaking head. I don't know, I won't even pretend to understand it or what / why this barrel likes .217's up.to.a.point (23's) and then ( apparently? ) switches off to .216's for anything heavier. (??) Whatever - I don't care at this point - if and when I find something that it likes - be it .216, .217, .218 or something else - that's just what I'm going to use.

The folks @Nielsen have done us a HUGE solid by offering those $5 a pop, 40 pack sample packages. I've now got three samples of .216's ordered up in the heavier 27.5, 28.5 and 31.2's. I bought this barrel and plenum to shoot heavy ammo - I'm gonna find something that it'll shoot. ( lol )

Gino (right?) - you think I should vice the block and give that barrel a good, solid torque to ensure that it is in fact squared up and seated as well as can be?

 

[mtnGhost]

Yes.. I should have added that: definitely put the block in a vice! I usually put mine in a vice with the block pointing upward so I can drop the barrel in without screwing up the threads.

 

[mercado]

That was my experience with my. 22 long it did not shoot anything heavier great..n for shooting 18 to 23g I dont need such a heavy bullpub....but when I try the 28g boat tails it shoot awesome but I was lacking the power to push them at 900+ fps .. at that time there were no plenums available...my .25 cricket barrel flex a bit n is 23 inches long...your at 27 n with the heavy shroud should be really bad with harmonics..if it was mine I would sleeve the barrel in carbon. The way Ernest are doing the fx liners n apply tension with a light moderator...o n try some 28g bt. 

 

[jdanvers]

.216's - all day! My sample packs showed up in the mail today - three of them, NSA's all .216 - 27.5, 28.5 and 31.2. I went straight to the heavies and after finding a half decent / accurate consistent speed - dialing up on the hammer spring - they seemed to settle in pretty good around 923fps.

Not changing the gun at all - keeping the HS the same - I slapped in the 28.5's. As expected, they flew faster @962 avg (10 shots shooting over my chrony) and they grouped . . . 'eh - "ok". I could likely improve on them by diddling with the HS and go slower / faster and see if I could find something but . . . I didn't. I was already leaning towards settling on the heavier 31.2's - ie; buying a box or two of them.

Still leaving the gun at the same tune - I ran the 27.5's through it and . . . whoa. 974avg and these were grouping extremely consistently and super tight at 41.

* oh yeah -- I zero @40 but I 'eyeballed' the test target when I set it up today and when I did finally measure it with my rangefinder - 'eh - I was off by a yard. Close enough . . . lol *

. . . so back to the 27.5's. These things kick ass - I may run with these vs. the 31.2's

The 31.2's @923 = about 59.04 ft/lbs ( based on this calc )
The 27.5's @974 = about 57.94 ft/lbs

That's only 1 ft/lb difference and I'm thinking that the 27.5's - because they're flying faster - are probably a flatter trajectory too - yes? Woodchucks at the receiving end of these aren't going to be able to dispute / distinguish 57.9 from 59 ft/lb's of something smashing into them - I'm pretty sure of that.

I didn't run the 27.5's out to 100 - Molly the dog was giving me "the eye" - she was getting hungry and wanted to go home. I agreed as I too was getting hungry. I did run the 31.2's at 100 though. Initially I was puzzled as I couldn't see through the scope where they were hitting until I finally noticed them off to the left. There was a r-l breeze blowing - maybe 7-10mph . . . once I figured that out and held off to the right a little bit then I started at least putting them on target. I'll try the 27's tomorrow out at 100 - I'm thinking I can get them tighter. ( this is the first time I've shot 100 in quite a while - rusty . . . yeah - thats my excuse )

Pics below were with the 31.2's. The top circle was the first 9 shots, aiming at the circle, and dialing in the speed via the HS. The 3 at about 5:00 is where it seemed to tighten up pretty good in the low 920's. I adjusted the crosshairs on the scope and loaded another 5 into it and went at the second circle below. I was happy with that. ( at this point still thinking I was zero'ing at 40 - not knowing it was actually 41 . . . whatever. lol ) 

Happy with that second group at "40" I decide to setup out at 100 -- I grab my rangefinder and setup another target out at 100. Only after I get back to my seat and dial up what strelok tells me I'll need for this 100 attempt do I think to verify my 40 . . . {sigh} ( strelok ranging might be a little off . . . ) Whatever - I'm just happy as a pig in doo doo that I've *finally* got this barrel shooting half decent. As you can see below and as mentioned above - wind was pulling them a bit - once I figured that out though - 'eh - not bad. Not great - but - for my first time shooting 100 in a while AND what with all of the issues I've had getting this 700mm barrel to shoot anything half decent - I'll take it!!