Mutant Taipan HST

[sactargetshooter]

The HST range of the Taipan (in my case, shorty version) is wide. At the maximum setting, even the shorty shoots 14.3 JSB Express at 936 fps for close to 28 FPE. Two turns out (counter clockwise), and it shoots the same pellets at 640 fpe. Another 270 degrees clockwise, it shoots the same pellets at 800 fps for FT matches.

What I would like is a truly tooless HST adjustment mechanism. I already caulked in the adjustment pins with a dab of epoxy putty, but still need a 2mm hex key to loosen/tighten the securing grub screw. I guess the use of a grub screw is not so much to save cost but to make sure nothing protrudes!

Minor, very minor complaint.

Using Chairgun, it is easy to map out the right zeroes for different power levels. I wish Chairgun can display bore line angle so it is easier to adjust the scope for different power levels. I just use the trajectory graph and read the values off of the y-axis after configuring Chairgun to display bore line. Again, minor complaint as it is no biggie. I tested this approach and was able to switch from 20 FPE to 13 FPE quickly.

I know many of us can care less to detune an AG. To some, there are several important aspects to detuning:

 

• shot count: efficiency is not linear to muzzle energy, I suspect the gun has more than 2x shot count at 13 FPE compared to 28 FPE. This is important to me because I hand pump the gun.
• point blank range: if the gun is used for hunting (and the Mutant is, for the most part, a hunting gun!), it is nice to be able to adjust muzzle energy to fit a particular PBR. Unlike being in a FT match, there is no time to range and look up the right mil dot!
• report/noise: as effective as the Mutant shroud is, even with extension, it is still more quiet at 13 FPE than it is at 28 FPE. This makes a rather big difference shooting indoor for practice purposes. I find that the impact on a "silent" trap is much louder at 28 FPE, but that is to be expected due to energy conservation. All that energy has to go somewhere!

So, for those of you who want a wide range of power settings that is easy to adjust with precision, the Mutant is, IMHO, a really good option.

[Rico14]

Does the adjustment knob have clicks as you turn it or does it just turn. Having clicks would let you easily return to a previous setting

[sactargetshooter]

No clicks. You can use paint to mark the HST bolt itself, and use a tape on the receiver to indicate positions. I just use paint on the receiver and paint on the blob of epoxy putty that I use to hold the pins together.

The key is how to align the adjustment screw relative to the receiver when you adjust. I always line up in a certain way for consistency.

An alternative is to use a caliper to measure the length of adjustment bolt out of the end of receiver. Guess that is a more scientific/engineering method.

[Rico14]

You can always use the chrony too but it would be a lot easier if it was like he scope turrets

[Zebra]

It's not a good idea to mess with the HST adjuster on the Mutant.

I know it might seem like an inconvenience to need two sets of tools to adjust it but that is by design and for good reason. On guns that have power adjuster screws that can just be turned by hand, they can develop consistency problems over time as they become loose and "adjust" on their own.

You see people complaining about their guns not retaining zero or a poi shift over time. Part of the reason is movement in all the threaded components. One of the reasons why the Mutant is so accurate and consistent is the extra screws they have to lock down components that might move and shift the poi.

It's one of the only guns I have seen to lock down the HST adjuster and the shroud etc so they don't move when you don't want them to. It's a great feature that I wish other manufacturers would copy.

The idea of constantly adjusting the power on the fly so you can use less air for plinking and more for hunting etc, it sounds great in theory but , in reality, it's not very useful. Every time you change the power, you shift the poi and you have to re-zero. The HST adjuster is something you use once when you fine tune the gun to work well with a particular pellet and then you lock it down and don't touch it again.

[TF89]

I agree that it can be easier and more stable to have one pellet, get it dialed in and then use it at the same fps, no matter what range.  If you want a gun to shoot at lower fps then get a gun that is setup to do that. 

To jump on the other side of that, it is also a preference thing.  I have multiple guns for various purposes mostly because I have air gun addiction issues and not an actual need for most of them.  I also think that when you find an accurate gun that is capable of shooting around various power ranges that is a good thing for the following reasons.

Budget, reducing number of air guns, sometimes a happier spouse.  Or even if a person is unsure of what the shooting environment is going to be.  Inside a building (where low power is king) to reduce noise and building, equipment, livestock damage and the ability to dial it up and shoot distance.

An example using what I own, a .22 disco for comparisons only as it is the only PCP I own.  It is zeroed at 30 yards with a ½ inch over and under POI at point blank range which is around 11 – 33 yards.  This disco shoots the 14.3 CHPs around 800fps from 1800-1100 psi and 600 fps from 1100 – 900 psi. I get an additional benefit in that my POA doesn’t seem to change much when I drop the velocity as my shooting range is 9 to 20 yards more or less.

The downside is that I have to back off the spring adjuster and reduce the psi.  To be honest, as you mentioned, even though the power adjuster has marks for those adjustments, it doesn’t always seem to give me the same results, which gives some variance.  Recently to get around having to adjust it down, I used some .22 Benjamin Destroyers which fortunately for me shot about the same as the CHP.  This allowed me shoot at the 800fps range and reduced the amount of pass through with head shots as long as I was shooting down the body.  The CHP’s tend to pass through causing damage on the down range environment.

I talked a lot and I really just wanted to say that I can see both sides of the issue.  It really depends on preference and is that what you want to do with a high powered rifle.

Air guns are tools and also something to have fun with and that Mutant looks like it is extra fun. 

Keep the reports coming in on those Mutants.  I’m one of those who really likes the idea of one, just not the budget.

Dave

[sactargetshooter]

I now have some data points. I can readjust the HST to be within 10 fps of muzzle velocity. This speaks volume of the precision of machining and how well parts fit. Given this kind of consistency, as well as the accurate modeling of trajectory in Chairgun, I think the Mutant will be my do-it-all gun. I will dial it back up to FT muzzle velocity later and use a chrony to see how close I can get.

As a side note, this is one of the few guns that I have that shoots CPHP very well, better than JSB .22 Express!

[TF89]

Sweet!!!  Sounds like you are in for some fun.  I was not much of a buildup fan, however after smacking my barrel around when moving in close quarters, it growing on me.

[Zebra]

An example using what I own, a .22 disco for comparisons only as it is the only PCP I own.  It is zeroed at 30 yards with a ½ inch over and under POI at point blank range which is around 11 – 33 yards.  This disco shoots the 14.3 CHPs around 800fps from 1800-1100 psi and 600 fps from 1100 – 900 psi. I get an additional benefit in that my POA doesn’t seem to change much when I drop the velocity as my shooting range is 9 to 20 yards more or less.

The downside is that I have to back off the spring adjuster and reduce the psi.  To be honest, as you mentioned, even though the power adjuster has marks for those adjustments, it doesn’t always seem to give me the same results, which gives some variance.  Recently to get around having to adjust it down, I used some .22 Benjamin Destroyers which fortunately for me shot about the same as the CHP.  This allowed me shoot at the 800fps range and reduced the amount of pass through with head shots as long as I was shooting down the body.  The CHP’s tend to pass through causing damage on the down range environment.

I talked a lot and I really just wanted to say that I can see both sides of the issue.  It really depends on preference and is that what you want to do with a high powered rifle.

Keep the reports coming in on those Mutants.  I’m one of those who really likes the idea of one, just not the budget.

Dave

The point I was making isn't about the repeatability when you adjust the HST. I am saying that the Mutant locking down the adjuster with additional screws to stop it moving, that contributes to it's unusually good precision, so it would be a mistake to remove this feature.

Also, adjusting the hst on a regulated gun like the mutant is not the same as on an entry level unregulated gun like the Discovery. To function efficiently, there has to be a balance of fine-tuning between the valve, HST and regulator. If you want to drastically reduce or increase the power, you would also want to adjust the  reg and not just the HST for it to function well.

The adjustability with the HST you get on gun like the Mutant and Cricket is for fine-tuning for specific pellets only. It's not to shift between backyard plinker and brutal hunter. Changing the power always  shifts the poi. That's the whole point of adjusting it.

[dman1114]

All true zebra...  but with that said, the mutant can be turned up and down with just the hammer spring adjuster and still perform better than most pcps.

If turning the hammer works for you go for it...  the mutant still holds strong

[jp_over]

The HST range of the Taipan (in my case, shorty version) is wide. At the maximum setting, even the shorty shoots 14.3 JSB Express at 936 fps for close to 28 FPE. Two turns out (counter clockwise), and it shoots the same pellets at 640 fpe. Another 270 degrees clockwise, it shoots the same pellets at 800 fps for FT matches.

What I would like is a truly tooless HST adjustment mechanism. I already caulked in the adjustment pins with a dab of epoxy putty, but still need a 2mm hex key to loosen/tighten the securing grub screw. I guess the use of a grub screw is not so much to save cost but to make sure nothing protrudes!

Minor, very minor complaint.

Using Chairgun, it is easy to map out the right zeroes for different power levels. I wish Chairgun can display bore line angle so it is easier to adjust the scope for different power levels. I just use the trajectory graph and read the values off of the y-axis after configuring Chairgun to display bore line. Again, minor complaint as it is no biggie. I tested this approach and was able to switch from 20 FPE to 13 FPE quickly.

I know many of us can care less to detune an AG. To some, there are several important aspects to detuning:

 

• shot count: efficiency is not linear to muzzle energy, I suspect the gun has more than 2x shot count at 13 FPE compared to 28 FPE. This is important to me because I hand pump the gun.
• point blank range: if the gun is used for hunting (and the Mutant is, for the most part, a hunting gun!), it is nice to be able to adjust muzzle energy to fit a particular PBR. Unlike being in a FT match, there is no time to range and look up the right mil dot!
• report/noise: as effective as the Mutant shroud is, even with extension, it is still more quiet at 13 FPE than it is at 28 FPE. This makes a rather big difference shooting indoor for practice purposes. I find that the impact on a "silent" trap is much louder at 28 FPE, but that is to be expected due to energy conservation. All that energy has to go somewhere!

So, for those of you who want a wide range of power settings that is easy to adjust with precision, the Mutant is, IMHO, a really good option.

Any long term update on how this adjustment practice worked out (using the hammer spring only)?  I'd like to turn the power down a bit on my Taipan Veteran .25 (from 900 to 780 or 800) for greater shot count and to be a bit quieter.

Thanks!

[miksatx]

Any long term update on how this adjustment practice worked out (using the hammer spring only)?  I'd like to turn the power down a bit on my Taipan Veteran .25 (from 900 to 780 or 800) for greater shot count and to be a bit quieter.

Thanks!

Grab your chrony and a Allen key that fits the set screw that locks hammer spring adjust. I adjust mine a quarter turn at a time. start shooting till ya find the velocity ya are shooting for.

[jp_over]

miksatx - thanks for confirming, will do!

[gendoc]

turn clockwise til it won't cock, then counter-clock 1/8 turn until it does cock.
 thats for max power like i want......

[zx10wall]

Here’s a solution that keeps all the functionality but can be adjusted without tools:

https://donnyfl.com/products/mutant-hst-adjuster

[Dbez1]

Here’s a solution that keeps all the functionality but can be adjusted without tools:

https://donnyfl.com/products/mutant-hst-adjuster

X2

[jp_over]

Well, I went the opposite way and adjusted it a bit higher.  I decided to keep my .22 Bantam for low power work. 

Here are my results.  Any advice on how tight to keep the grub screw?

[miksatx]

Well, I went the opposite way and adjusted it a bit higher.  I decided to keep my .22 Bantam for low power work. 

Here are my results.  Any advice on how tight to keep the grub screw?

Never had the grub screw come loose. Could replace it with one with a nylon tip

[jp_over]

Well, I went the opposite way and adjusted it a bit higher.  I decided to keep my .22 Bantam for low power work. 

Here are my results.  Any advice on how tight to keep the grub screw?

Never had the grub screw come loose. Could replace it with one with a nylon tip

Good info - thanks!