Tuning TAIPAN CZ 700MM BARREL - THERE'S HOPE!
- Thread starter mtnGhost
- Start date
Uff, this will take a minute to cover in detail. First, I haven't yet tested every .22cal slug on the market with the chokeless CZs. My trigger time has also been fairly limited this past ~7-8 weeks, however I have spent most of that time focussing on the slugs that I wanted to test the most.
My other testing issues have been around the shooting table that I'm using (very wobbly, even worse in the wind). I can't use my shooting mat in the two primary locations that have flatter ground where I can setup all my gear), due to the heavy vegetation growth of this summer (1-2m high).
Despite those problrms, I have been able to test several different varieties of slugs that perform well (at various distances) in the harsh winds that we have damn near all year in the Pacific NW. Here is what has and has not shot well thus far (from best to worst):
40gr Griffin RBT HP 2S nose .217 - consistently stellar performance in the 600mm & 700mm barrels that definitely sub-inch at 100m (probably greater if I had a stable shooting platform to test from). They've been accurate from 780-1000fps, but my guess is they will destabilize once they go supersonic (I haven't tested supersonic yet with this ammo in the chokeless CZs)
24gr Varmint Knockers 2S nose HP (.217) - extremely accurate, sub-inch from ~800-1075, closer to 1/2" from 1076-1105 (1100fps appears to be the "magic" velocity in both the 600/700mm bbls).
20.2 & 24.8gr NSAs, 25gr H&N (.217) - sub-inch to an inch, but I'm seeing consistently better results with chokes
29, 30, 34, & 36gr Griffin RBT HP 2S nose (.217) - just over MOA accurate at 100m. Better performance with chokes
32.80gr XLHP, 34gr Varmint Knockers (.217) - these at 1.2". I have not yet tested the 2S nose version of the 34gr - rather the ones he sells with the larger meplat diameters
24.8gr NSAs (.2165) - not as good as .217 in my custom bbls
42, 44gr Griffin 2S & 40, 42, & 44gr 4S nose - the 42gr 2S is ok (~1.25" at best), but NONE of these 4S nose slugs shoot well. They are dangerously unstable (Mike Walker from Griffin told me he is seeing better results with faster twist rates with his 4S)
Now I've had a major problem with my SideShot's GoPro Backbone lens - very hard to get it refocussed where it was prior. So after wasting several trips driving 3-4 hours to test and record ballistic videos,
I finally had a chat with Claudio Flores who has the same scope cam setup as I have. He gave me some tips, and I bought a micro-HDMI to HDMI cable and brought a computer monitor with me on my last trip out to the mountains LOL! Got the lens threaded back down VERY close to where it needed to be, but when I recorded the shot strings that day at 240 frames/sec, I forgot to shield the eye relief gap between the Sideshot and scope eyepiece, so the videos had varying degrees of sun flaring
I posted a video of the group that I shot with the 700mm CZ configuration the last time that I was out, but my primary focus that day was testing the 36, 42 & 44gr 2S and the 40, 42, & 44gr 4S Griffin RBTs with the 600mm & 700mm rifles:
https://m.youtube.com/watch?v=3rq55cph8lU
It's hard for me not to get excited about the performance of these 40gr 2S RBTs!! The BC is averaging 0.161 RA4 (0.163 with a tail wind). The 24gr 2S Varmint Knockers are also VERY accurate with a 0.113 BC average (RA4, but I use 0.118 G1 for long range depending on the wind).
So at this point in time, I would conclude that .217 will perform the best with most airgun slugs. I need to test some of the 27-30gr H&Ns soon, and maybe some of the JSB Knockouts, but I personally gravitate towards the higher BC ammo.
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Thanks for sharing!
I see a lot of time in testing and posting, thumbs up.
Unfortunately those griffin slugs are not for sale in my country.
H&N in al sizes are no problem.
Do you have plans in testing them to?
Regards, Robert.
I see a lot of time in testing and posting, thumbs up.
Unfortunately those griffin slugs are not for sale in my country.
H&N in al sizes are no problem.
Do you have plans in testing them to?
Regards, Robert.
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Yes, I definitely plan to try the 27 & 30 grain soon. The 25gr didn't do as well as they did with the FX slug A liners in my Vets, but I believe the geometry of these two heavier slugs will be more compatible.
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Even I'm excited seeing the performance of those slugs! Awesome man! How many shots per fill do you get setup like that?
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Thanks man! So with the Standard size air cylinder, two plenum extensions, and my valve & hammer systems, they're getting around 11-12 shots per fill at 105-110FPE shooting 40gr. I had turned one of my two Standards up to shoot them at 1140FPS, but that little 10 bars extra or whatever it was killed my shot count (8 shot maybe lol).
I have (3) other Taipans (Long, Shorty Vet, Shorty Mutant), all are running my valves, hammers, barrels, but I never recorded the shot counts with any of them shooting 40gr or heavier. The Long will get more shots for sure, I'll probably test that soon.
I had tuned the Compact Vet a while ago to be pretty hot like my Standards (no plenum extensions), and ran the 34.1gr VKs (.217) up to 1000fps with the 500mm slug A liner. I dialed down the hammer setup and found that I could get 10 fully regulated shots at 950 (11th shot was 932), so that was pretty interesting!
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Wow that's crazy! More than I really figured pushing over 100fpe! And a little Short pushing 10 shots at damn near 70fpe is insane. Love my Short but only have it tuned at 27fpe lol. Would be fun to shoot some lighter slugs from it at times though!
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Enquiring minds wants to know where you’re finding the CZ barrels . I’ve scoured the internet and have found no where that sells them. The closest I’ve come was a factory takeoff from a CZ457 MTR but it was only 16”. I have an old BSA barrel that shoots great , but would like a 700mm CZ to make some power.
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Thanks , I highly doubt they would ship to Canada but I’ll give them a try anyway. Thanks again .
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Hmm is there a Canadian dealer for Taipan? If not, I could probably ship one to you when I have them.
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No Taipan dealers here . Part of the whole bull pup laws here. When you get them please let me know if sure love to get my hands on one .
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Thank you sir!!! I need to build a more solid shooting table for getting better video a d groups on days like that. These 40gr RBTs are capable of better than what I was able to do that day on that trampoline table, and I almost decided not to publish the video.
That particular spot on the side of that hill near the top of the clear cut valley is great for testing ammo in the wind though! I couldn't think of much worse terrain for benchrest shooting
Will do!
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