Tuning Taipan tuning question

I have played with the idea of shooting in the Extreme field target shoots. I have not. shoot air guns at that distance. My Taipan is set to shoot 18 grain JSB at 916 FPS. Finding my scope settings at various yards I have shot good groups at 100 where I was confident with my scope setting than the next time I would shoot at that distance with a little wind my pellets scatter enough that I can not be confident in the scope setting. So I ordered a couple tine of heaver pellets to try. As I wait for my order I wonder if when I get them If I need to change velocity should I try adjusting the hammer spring or should I adjust the regulator. I am very satisfied with the taipan now out to 75 yards and may want to return to this set up?



Jim 
 
If you can get to your desired velocity with the heavier pellets using only HST adjustment, do that. If you like the results, then you can see where you are in your tune, and adjust the reg as/if necessary. Also, have you tried the 18 at slightly lower velocity? Your current setting at 916 fps sounds a bit fast. But, rifles vary, and it may be perfect for you.
 
For the best results*, the regulator's setpoint and the hammer spring tension need to be adjusted in tandem. Or to put it differently, there is one optimal hammer spring tension for whatever the regulator pressure happens to be.

This balance point is where the gun is producing about 95 - 97% of its peak velocity. To find it, gradually dial up the hammer spring tension until the velocity no longer increases. Then back it off until the velocity falls by roughly 3 - 5%. So in other words if the velocity peaks out at 920fps, back off until it is somewhere between 874 and 892fps. If the resulting velocity isn't where you want it to be, change the regulator's setpoint and repeat.

* By "best results" we are talking minimum extreme spread, resistance to the effects of regulator creep or linearity, good efficiency, etc.
 
I have the Taipan .25 Long. When I first got the gun from Talon Tunes, I asked Tony about the pellets that he uses for his testing. He told me that it shoots best for him with the JSB 25G between 880-920 FPS. He also indicated to try the heavier 33G MK2, which is what I am using currently. 

In addition to doing what Ed suggests, I would also try the following approach which he passed on to me when I first purchased my Taipan. 

Begin your testing at 25, 35 and 50 yard intervals with each pellet. Adjust the HST accordingly to determine best tune. You can go further than 50 yards, but not necessary if you are not satisfied at the lower yardage. As an example, I expect and want to see a jagged one hole 5-shot group at 20-25 yards, and very close to a half inch at 50 yards with little to no wind and good outdoor conditions. If the rifle and ammo can do this, I can then bring it out to further distances to assess those groups. BTW, any wind even as low as 1 mph can distort your analysis as you increase distance. So, I would try to get a near perfect day with little/no wind for your testing. 

Next, I would do as Ed mentions and lower HST on the JSB 18.1 to begin at around 850 FPS perhaps as a starting point and increase in 10 FPS intervals with HST adjustments. My Daystate Regal XL (when I had it), my FX Royale 400 and HW100 .22 cal rifles all shoot very well in the 850-880 range, dependent on each rifle’s liking. If you like a lower velocity, try it at 75yards and determine if it is better or worse than your 916 FPS HST setting. 

Make sure you mark the HST adjuster with a visible mark where you like it now for your 75 yard preference. This way, you can easily go back to your original tune.











 
Thank you both. The current setting could be a little fast. I suppose I should try slowing down a bit. The shot string with JSB 18 was tight for 60 shots 904 / 917 extreme spread and the gun shot great out to my property 75 yard limit. So I just shot it without trying any adjustments. I did buy a tin of 25gr rangmasters. I only shot them with this setup out to 55 once and they didnt group great. I never tried them again. I just bought about twenty tins of 18s and never looked back. The rangmasters may shoot better @ 100. I stuck them in a drawer somewhere I should try them again while waiting for the JSB's. 
 
My Taipan is the standard. 

@ 50 I can usually shoot groups under .5 out at 75 on a calm day it shoots groups not much bigger. One problem I encounter is my long range at my property is pretty protected from wind. Then when I shoot in wind I don't know what's going to happen and loose my mind. I think I will head out and play around a little.

Jim

If you can regularly or “usually” shoot less than 1/2” at 50 yards outdoors, you are at a very good accuracy point. Same with your current results at 75 yards. If I get those results, I am a happy camper. I would expect this would also be acceptable for extreme FT, but since I don’t shoot FT I am not sure either. 

In any case, it’s always fun and an adventure trying new pellets.
 
For the best results*, the regulator's setpoint and the hammer spring tension need to be adjusted in tandem. Or to put it differently, there is one optimal hammer spring tension for whatever the regulator pressure happens to be.

This balance point is where the gun is producing about 95 - 97% of its peak velocity. To find it, gradually dial up the hammer spring tension until the velocity no longer increases. Then back it off until the velocity falls by roughly 3 - 5%. So in other words if the velocity peaks out at 920fps, back off until it is somewhere between 874 and 892fps. If the resulting velocity isn't where you want it to be, change the regulator's setpoint and repeat.

* By "best results" we are talking minimum extreme spread, resistance to the effects of regulator creep or linearity, good efficiency, etc.

Quite true. But, if you have to adjust the reg by trial and error, it's more than a few minutes job in the Taipan. So, by using only HST and a chrono, you can usually identify whether a specific pellet/velocity combination is promising, and then move on to evaluating the balance of your tune, and adjust the reg accordingly. This assumes, of course, that you can reach a desired velocity with reasonable consistency with HST only. If not, then you have no choice, tear it down and adjust the reg. 
 
For the best results*, the regulator's setpoint and the hammer spring tension need to be adjusted in tandem. Or to put it differently, there is one optimal hammer spring tension for whatever the regulator pressure happens to be.

This balance point is where the gun is producing about 95 - 97% of its peak velocity. To find it, gradually dial up the hammer spring tension until the velocity no longer increases. Then back it off until the velocity falls by roughly 3 - 5%. So in other words if the velocity peaks out at 920fps, back off until it is somewhere between 874 and 892fps. If the resulting velocity isn't where you want it to be, change the regulator's setpoint and repeat.

* By "best results" we are talking minimum extreme spread, resistance to the effects of regulator creep or linearity, good efficiency, etc.



You really have a gift for explaining these things SO clearly!

Thanks!
 
First. the Veteran design (and or actual reg?) seem to be more tolerant than many other guns of adjusting hammer spring without the regulator and still getting consistent shot strings.

Second, and not mentioned yet here, is the matter of BCs. (AGN has a couple BC trolls that this type of discussion usually brings out of the woodwork so hopefully we can avoid them this go around. They are often the types who mostly shoot at 30 yards, which inherently makes their opinions not worth much when we're talking about taking pellets to 100 yards.) Anyway, in my personal experience shooting long range pdogs, long range paper, and the XFT matches, BC is proportional to wind deflection.

The 18.1s are a great pellet, and can shoot very accurate groups out to 100, as you've found. But also, as you noted, any wind and the 18.1s become a CHALLENGE. They usually have a BC of about 0.035, which only puts them a bit above the 10.34gr/.177 that is usually in the 0.028-0.034 range. And I've found the 10.34s only slightly harder to get to the intended impact point @ 100 (when compared to the 18.1/.22). 

The 25.4gr MRDs have a BC up around 0.05, a BIG jump from the 18.1s. If you go back and look at the equipment lists that I include in the XFT match reports, you'll see mostly MRDs being shot, with the 18.1s having been attempted a couple of times. Now, the saying about the worst day fishing is better than the best day at work kinda holds true here, you'll have fun at XFT no matter what you're shooting, but past matches have shown the 18.1s to typically have one of the lower scores for that match. I'm not against the pellet, and I would love to see somebody come kick trash with the 18.1s. If you are very familiar with what they do in the wind, and can read the wind really well, you are likely to beat everybody, but if the wind has you guessing, it'll be a challenge. An enjoyable challenge. 

if your Vet won't shoot the 25.4s as well as the 18.1s though, you won't have much of a choice. Shoot the more accurate pellet, even if it has the lower ballistic potential. 
 
The TV Long I had in 22cal loved MRD's and I mean loved them. I had it set at 890fps, but it was accurate at any setting I put it at. My Huma reg was set at 140bar and I did notice that anything lower than a JSB 18.13 had problems being consistent. I assume that reg would need to be set lower for more consistency. I will say this at 890fps with chronograph would read 890, 892, 891, 890, 890, 894, 891, 890.... and on and on. 
 
For the best results*, the regulator's setpoint and the hammer spring tension need to be adjusted in tandem. Or to put it differently, there is one optimal hammer spring tension for whatever the regulator pressure happens to be.

This balance point is where the gun is producing about 95 - 97% of its peak velocity. To find it, gradually dial up the hammer spring tension until the velocity no longer increases. Then back it off until the velocity falls by roughly 3 - 5%. So in other words if the velocity peaks out at 920fps, back off until it is somewhere between 874 and 892fps. If the resulting velocity isn't where you want it to be, change the regulator's setpoint and repeat.

* By "best results" we are talking minimum extreme spread, resistance to the effects of regulator creep or linearity, good efficiency, etc.

Quite true. But, if you have to adjust the reg by trial and error, it's more than a few minutes job in the Taipan. So, by using only HST and a chrono, you can usually identify whether a specific pellet/velocity combination is promising, and then move on to evaluating the balance of your tune, and adjust the reg accordingly. This assumes, of course, that you can reach a desired velocity with reasonable consistency with HST only. If not, then you have no choice, tear it down and adjust the reg.

This is exactly what I did when testing my Taipan .25 Long with both the 25 and 33 g pellets. I resisted adjusting both the HST and the regulator in tandem, because I just wanted to see how the pellets did at various velocities using just HST adjustments. Not disputing the value of doing both, I just did not want to spend the time with so many HST adjustments of messing with the regulator. 

Not only that but at 95-97% of peak velocity ( i.e., around 920-940 FPS), my velocity testing with the 25G pellet revealed that the accuracy at 920-940 FPS was not as good as when I went down to around 890-915 FPS with the 25g pellet. My Taipan Huma regulator is set to somewhere between 90-100 BAR, which I know is probably too low. I recall running an entire shot string over the Chrono and getting to somewhere in the neighborhood of 960-970 FPS maxing out the HST, then backing it off to determine the peak velocity. However, since I am getting good accuracy now using the HST adjustments, I am OK with the set point being lower than it probably should be here.
 
Back in early 2020, I installed a Huma regulator in my then new Taipan Veteran Long .25. I set the regulator at 130 bar, as that that seemed like a good starting point per forum discussions. The Huma reg has not been changed since, and remains at 130 bar today. These are my current HST settings for best long range accuracy:

JSB 33.95: 865-880 fps (depending on season) with HST on max setting.

JSB 25.39: 900-910 fps with HST about 3/4 of max setting.

Also, with just HST adjustments, I tried finding the 'knee' with the JSB 25's. However, at around 970 fps, the HST was almost maxed out, and I decided to stop.

Our Taipan's are extremely accurate guns, and mine will probably be the last in my stable to ever get sold.




 
The .22 Vet standard is a 35 FPE rifle so it sounds like you are close to being maxed out on speed. I would assume the JSB Redesigned will be traveling around 780 FPS out of your rifle. I haven’t tried them at this speed so I can’t comment on accuracy but it’s definitely going to have considerable drop at 100 yards. You could do a few power mods and get it a little faster but you’re limited by the factory 460 cm barrel more than anything else. I own all three sizes of the Veteran and while the standard is my favorite size of the three, the long version is much better suited for shooting out to 100 yards. The long’s barrel is 550 cm and it would be easy to do a barrel swap on your Vet. My long is shooting the Redesigned in the 890’s without any modifications. You could also leave it as is and use whatever works best for you out to 100 yards. The last and best option for you would be buying another rifle for XFT use now that you have an excuse to do so. At least that’s what I would tell my wife...


 
The .22 Vet standard is a 35 FPE rifle so it sounds like you are close to being maxed out on speed. I would assume the JSB Redesigned will be traveling around 780 FPS out of your rifle. I haven’t tried them at this speed so I can’t comment on accuracy but it’s definitely going to have considerable drop at 100 yards. You could do a few power mods and get it a little faster but you’re limited by the factory 460 cm barrel more than anything else. I own all three sizes of the Veteran and while the standard is my favorite size of the three, the long version is much better suited for shooting out to 100 yards. The long’s barrel is 550 cm and it would be easy to do a barrel swap on your Vet. My long is shooting the Redesigned in the 890’s without any modifications. You could also leave it as is and use whatever works best for you out to 100 yards. The last and best option for you would be buying another rifle for XFT use now that you have an excuse to do so. At least that’s what I would tell my wife...


All very true Eddie. I was not thinking about the Standard probably being a bit underpowered for the 25.4s, in OEM form. 
 
Where my reg is set now - with the hammer where it is the 25 gr shoot 770 - with my hammer spring turned in 1 1/2 turns tighter I can only get 850 fps with the 25 gr rangemaster. At that setting I get 3-4" group @ 80 yards. And the gun is loud! 1 3/4 turn in the gun won't cock. 

I decreased my velocity 890s with the spring and I do believe it shoot's better and more consistent. I shot a 5 or 6 shot 3/4" group no wind. I shot 3 magazines into a 1 1/2 group. I got tired and didn't try other yardages with this setting.

I wish I hadn't of but last night I ordered 10 tins of 25 gr JSB's I will try them when they come in but I dont have any hope for them really. Even if I were to increase the reg setting. But I may be wrong.

notes took while shooting:

IMG_1276.1641767521.jpeg



 
Jim

I would not worry about having 10 tins of RDs, they are in constant demand if they don’t produce. You can always sell them to me if you don’t like. But, you should give them an honest try with the guidelines from the other post previously. 

Like I said earlier, if you are getting LESS than .5” at 50 and pretty close to that at 75 yards with the 18 g; this is Not a concern for XFT in my view.