This report covers:
- Something else
- AirForce
- 21-speed bicycle
- TalonSS
- More power?
- Other power adjustments
- Setup
- Another way to get power adjustability
- One more way to change velocity
- The thing is…
- Summary
I was all set to do the velocity test on the Gauntlet 2 PCP rifle today when it suddenly occurred to me that I was stressing out about how to test that rifle. Some of the reason for that stress will come out in today’s report, because I want to talk to you about the downside of adjustable power.
The Gauntlet 2 doesn’t have adjustable power, but it does have a lot of shots and it fills to very high pressure, and I have been asked to test odd things, like how many shots the test rifle gets with a fill to 3,000 psi. That got me thinking about how involved and difficult it is when I test a gun with adjustable power. And that is where today’s report came from.
Something else
Many people seem to want what they don’t have — or at least they think they do. If they hear about something they wonder aloud why it wasn’t also designed to do something else. Let me give you some illustrations.
AirForce
When I worked at AirForce Airguns I took all the calls that came in about modifying the rifles. One guy wanted to shoot as fast as possible, so he tethered his Condor to a helium tank and claimed a muzzle velocity of 1,700 f.p.s. Another guy was fanatical over having his air tanks “balanced” to give the same velocities at the same power settings. He sent me his rifle and spare tank, asking me to “balance” the valves in both tanks to do just that. The thing is — that is almost impossible to do. He was of the opinion that if we made the rifle surely we could set up each tank to shoot at the same velocity on the same power setting. But it can’t be done by any means beyond sheer luck, any more than two V8 car engines of the same model can be tuned to give exactly the same power on a dynamometer at all speeds. Sure, you can get two engines to read the same at a certain RPM, but change that RPM and they will not be the same.
Another organization wanted to shoot our TalonSS rifles at 500 f.p.s. and no faster than 600 f.p.s. Now that is more feasible because they gave us a range of velocities. And the TalonSS will shoot that slow right out of the box. You just won’t get a large number of consistent shots from it at that speed. You might start out at 508 f.p.s. and by shot 20 you’re up to 736 f.p.s. Why? Because the valve in the rifle was really designed to shoot .22-caliber pellets in the 850-950 f.p.s. range. Yes, it can be adjusted slower, but it doesn’t like to remain there. People may want that kind of flexibility, but getting it is a whole other thing.
That organization was the National Rifle Association and the reason they wanted our rifle to shoot so slowly was because they were using Daisy pellet traps on their public range at their annual meetings where our rifles were being used. An 800 f.p.s. rifle would soon shoot through the thin steel backer plate of the Daisy traps. They also wanted to get lots of shots on a fill because the public was lined up deep to shoot our airguns.
The solution was to use an air valve we called the “double restricted” valve in house. It had a lighter return spring and a very tiny air orafice in the valve stem. John McCaslin built it just to see how many slow shots a Talon SS could give. After hearing the NRA’s requirement for the range, he built several more such valves and they have been on the guns we use at the NRA public range ever since. You can also buy one of those valves in a new tank today. It’s called a MicroMeter tank.
Yes, such things can be done when there is a solid reason to do so and also a solid specification to meet. And yes, the same TalonSS rifle that can shoot that slow can also be brought back to full power with a standard air tank and valve — that is the beauty and wonder of the AirForce system. But you need to understand that the power adjuster wheel on the left side of the rifle is not enough by itself to do both things — low speed and high speed with consistency.
The guy with the helium tank was a crazy science experiment. Imagine going into the woods searching for squirrels with an air rifle tethered to a 5-foot steel tank of helium! The guy who wanted balanced tanks was just too lazy to check both of his tanks over a chronograph to find where the power adjuster on the rifle had to be set for each tank to give him the same velocity.
21-speed bicycle
I have a 21-speed bicycle and it does use all 21 speeds to accomplish different things. You can pedal easily up a steep hill in the low range and first gear. And you can fly like the wind on a level road or a slight downgrade in the high range and gear seven. But that bicycle was built around those 21 speeds. That is one of its principal performance features. Guns aren’t made to do that. They are made to hit things when they shoot.
TalonSS
You can get a .22-caliber TalonSS to shoot consistently at 775 f.p.s. up to about 850-875. In that range the rifle can be very consistent for a decent string of shots. Heaven forbid that accuracy should enter the equation, but if it does I have found my TalonSS to be most accurate with .22 pellets weighing 14.3 grains exiting the muzzle at around 820-830 f.p.s Do you see how specific things get when you actually want to do something? So my adjustable TalonSS power wheel is set at about 8.10, or so. I say “or so” because my SS was not engraved with the power settings. So I have to guess where the adjuster is set.
More power?
If you want more power from a TalonSS the easiest way I know of to get it is to add more barrel. And AirForce guns are made to swap different lengths of barrels in different calibers in minutes. By installing a 24-inch .22 caliber barrel on a TalonSS after removing the 12-inch barrel, the power jumps from about 22-23 foot pounds to 43-44 foot pounds with no other changes. However, you loose the quieting that the shorter barrel has because the longer barrel sticks outside the frame. The rifle also becomes longer overall.
Does the longer barrel still have adjustable power? Yes it does. In fact, because the barrel is longer the adjustment range becomes a little larger. The rifle can dip down to almost the high end of the shorter barrel, but of course with a lot less air being used. So more shots on less air. But the difference isn’t that great. You don’t double the number of good shots. You might get 5-10 more.
The power adjustment wheel on a TalonSS is designed to refine your power within a narrow band of velocities.
Other power adjustments
Let’s look at another power adjustment — the one that comes on the Beeman P1 pistol. There is a low power setting where the piston is caught by the sear at one place in the cocking stroke and a high power setting where the piston is caught with the mainspring more fully compressed and the piston stroke much longer. Even though the pistol has those two settings I seldom use the lower setting. The trigger breaks more cleanly on the high power setting, so that’s where I cock the gun every time.
The Crosman Mark I and II Target pistols have the same arrangement, only it’s the hammer that gets caught in either of two places. But the trigger is crisper on the high power setting, so that’s where I cock the gun every time.
Setup
I know that people who are dreaming about getting an airgun with adjustable power spend time daydreaming about all the things they can do with it. People who own airguns with adjustable power spend their time setting it up to do its best at just one power setting. That’s the difference between dreaming and doing.
Another way to get power adjustability
With the .458-caliber AirForce Texan you can change the weight of the projectile to change the power dramatically. For example, if you shoot a round ball that weighs 143 grains, it goes out the spout at 966 f.p.s. and gives about 296 foot-pounds of energy, but if you shoot a 405-grain bullet it exits at 750 f.p.s., giving about 506 foot-pounds at the muzzle. That’s more than a 200 foot-pound energy difference from a 216 f.p.s. velocity difference. And all you did was change what you shot!
One more way to change velocity
Ever hear of a multi-pump pneumatic? They are sold on the basis of user-adjustable power. But users quickly learn that the number of pump strokes also changes where the pellet lands. It’s not a simple 3 pumps for 15 yards and 8 pumps for 40. Things other than the trajectory change as the number of pumps change.
The thing is…
The thing is — you don’t make these changes without changing where the projectile impacts. And you also change the size of the group, which means changing the accuracy of the gun. Since the main objective is to hit what you shoot at, when all the silliness is stripped away the bottom line is you set up the gun to shoot one way accurately and then you do it. You don’t keep changing the velocity or the power of the gun.
Summary
Adjustable power sounds great, and it really can be, but the user has to understand all that is involved.
The best long range shooter at my range. Set’s his FX impact at 940 fps and shoots 5 shot groups at 100. Then he lowers his pressure by about 25 fps for each .25 grain pellet and slug. He does this until he gets to about 820 fps. Repeat with different slugs/pellets. That way he knows at what speed his gun with his barrel stabilises that pellet the best.
-Y
BB,
Adjustments seem to be the boon and bane of airgunners. Give them nothing or too little to adjust and they complain. Give them too much to adjust and they will tinker with it until it doesn’t work. It’s hard to find the Goldilocks spot for everyone. Then again that could be said to be true for a lot of items.
Siraniko
PS: Section 21-speed bicycle 1st paragraph 2nd sentence: “You can peddle (pedal) easily up a steep hill in the low range and first gear.”
Siraniko,
Fixed it. Thanks,
BB
BB,
Interesting that you should bring this up.
As you have shown us, the power of airguns can be changed if you are willing to go inside. But, using your bicycle analogy most are like coaster bikes… one gear. They are designed to a specific performance/pellet and you are pretty well stuck with that. I’m kinda surprised (considering slugs and such) that more airguns are not (easily) adjustable.
To illustrate that, recently I’ve been looking at RAW and Daystate PCPs and it seems that the rifles are factory tuned to a specific pellet weight. The HM-1000 & Wolverine R appear to be tuned to an 18 grain pellet and the HM 1000X & Wolverine R HP to a 25 grain pellet. To change the tune you have to disassemble the rifle!
With airguns with a “fixed tune” you are forced the find the golden pellet that matches the tune.
What I like about adjustable (PCP) airguns is that you can chose an energy level, select a suitable pellet and tune for best performance.
My FX Impact came factory tuned to shoot an 18 grain pellet at 33 fpe – pretty much what you would expect from a. 22 caliber PCP. I’ve also tuned it to (accurately) shoot pellets from 13 to 25 grain (15 to 45 fpe) …just because I was curious 🙂 Like a 21-speed bike, the options are there if you need them.
For an adjustable airgun might I suggest you test two pellet weights, a “power tune” for hunting and a backyard friendly “plinking tune” that is geared to quiet shooting and high shot count.
Hank
Hank,
I would not recommend an Impact to a newbie. You have a pretty good idea what you are doing. Even an AirForce airgun can be adjusted so out of whack it hardly even works, more or less hit what you are shooting at, even if it is an elephant’s backside.
The RAW is designed and tuned for supreme accuracy from the factory. I can easily adjust my hammer spring to have my HM1000X shoot from 80 FPE up to 100 FPE. I can probably go lower than 80 FPE, but I have not tried.
It is true that I would have to take it out of the stock to adjust the regulator if I want more power. What for? It will shoot an one inch group at 100 yards now.
If I were going to hunt with it using cast bullets, I would indeed desire to crank up the power a bit and change the barrel, but that is what you do with that Impact. I can legally hunt deer here with my HM1000X, but like you I would much rather just look at them. I have a doe with four fawns running around here right now. 🙂
P.S. Would it not be easier to have an air rifle for hunting and one for plinking? You are not going to just flip a switch and have it as an awesome plinker one second and a deadly accurate hunter the next. This is what BB is trying to say here.
RR-
Just to clarify about your RAW HM1000x- are you saying that it gives 80 to 100 FPE and that is legal in your state for whitetail deer hunting?
Paco,
Not necessarily. The caliber, .357, is large enough. I would not gut shoot a deer with this air rifle at that power level. Of course, I would not gut shoot a deer. I would shoot for the brain. It kills much more quickly. The HM1000X is also accurate enough to do just that.
If I was going to hunt with this air rifle, I would adjust the regulator much higher. I do not need to. I do not hunt anymore.
So, caliber is the criteria rather than energy level, I take it? Thanks.
Pacoinohio, you must check the laws and regulations where you hunt. Some states allow hunting big game with big bore airguns, but certainly not all.
Bravo RidgeRunner: “…I would much rather just look at them [deer]…”. I like the sentiment. 🙂
If I needed to in order to feed my family, the deer around here would be in serious trouble. Fortunately, I do not need to do such. Nowadays I just shoot them with my camera.
“I would not recommend an Impact to a newbie.”
RR, I’ve debated that quite often. Agreed, if you don’t know what you’re doing and start twiddling the dials all over then you can really mess things up.
…But, if you record the factory settings in the chart in the owner’s manual (like FX recommends you do) then it should not be a disaster. 🙂
The flip-side… If the newbie could keep his hands off the adjustments then an Impact (or a Crown) might be the ideal choice for someone who wanted (only) one PCP. The rifle could be tuned to a specific purpose (by a Pro) as required. E.g. a plinker tuned for 2 months of hunting in the fall.
Say that you moved from Vermont to Texas, I like that the Impact can be changed from a squirrel gun to a hog gun if needed.
I wouldn’t recommend swapping calibers all over the place (you can easily do that but it is expensive and the gun needs to be retuned) but the option is there. Best as you say, get two dedicated guns.
I like the .22 RAW HM 1000X LRT very much, they are awesomely accurate and was seriously considering one. The thing is that I want to be able to shoot light weight pellets as well as the 25 grain Monster Redesigns (and slugs), Don’t like being restricted to one choice especially these days where pellets are often back-ordered for months.
JSB pellets are hard to come by so I was happy to score a bunch of tins of Crosman HP’s at the local hardware store. Didn’t take long to dial the Impact in to the 14 grain HP’s. 🙂 They’re OK for plinking straight out of the tin and shoot pretty well if you weight-sort them.
Don’t know. As I said, I’m surprised that more PCPs (especially the high end ones) are not “user friendly” as far as tuning goes.
Hank
Hank,
Completely off-topic, but when you get around to that HW30S, keep Canada Shooting Supply in mind as well – they stock the Beeman R7s.
Cheers,
Nathan
Thanks for the reminder Nathan!
I may end up going that route.
Hank
Hey Nathan!
I checked Canada Shooting Supply, the R7s were out of stock and they had no idea if/when they would be getting more.
Same problem with D&L, HW30S has been backordered for almost a year now and still no ETA.
Found a. 177 caliber R7 at AGS. Wasn’t planning on buying until the spring but with availability problems everywhere I said to heck with it and ordered one. …It arrived today with a light little Hawke 4X32 AO scope, mounts and a couple of tin of pellets 🙂
First impressions are very good – nice sized air rifle, points very well (like all Weihrauchs seem to), trigger is great and shot cycle is calm.
Can see why it gets so much praise – think the R7 is going to be a favorite plinker 🙂
Thanks for the nudge!
Hank
Hank,
Glad you found one! I hadn’t realized AGS had gotten in new stock – that’s where I got my HW30S as well. Pretty funny that they’re slightly more than the HW50S, but it’s a delightfully handy gun. I find it perfectly sized, like a nice rimfire rifle.
Cheers,
Nathan
Sometimes the company I work for calls on me to visit a location and remove some pest.
For this I use an ancient Gunpower Stealth from 1998 (a UK version of an Airforce Talon, in .22 caliber but it has no power wheel.)
I do use adjustable power for different situations.
But I do have time to set up for the different task.
To adjust the power I have to change tanks.
The UK (United Kingdom) tank limits the gun to sub 12 ft lbs, and is perfect for indoor pigeons and other pest.
If I have a pass through shot, or heaven forbid a miss, it lacks the power to penetrate the steel building.
When I have to shoot pest at longer ranges outdoors, under covered parking I use a standard Airforce tank that produces 20ish ft lbs, and my notes remind me what mildot to use for my zero at what magnification.
I also have a Co2 adapter, that delivers less than 10 ftlbs of energy for really unusual circumstances and my notes remind me of what mildot it shoots at what magnification.
Guns are like golf clubs and women’s shoes., very rarely does 1 gun serve many purposes well, so buy several.
And your wife needs more than one pair of shoes because not every shoe goes with every outfit..
Be prepared for her to remind you that her shoes don’t cost $300 a pair though….
Yes I am back!!
Ian..
Ian!
Whoohoo! I do not know about anybody else, but I missed you.
You give some good analogies. A hammer does not cut wood well.
Thank you I have missed being here.
12-14 hour days for 30+ days with no breaks takes its toll.
Remember the old Dunkin Donuts commercial?
The guy waking up every morning and walking like a zombie “time to make the donuts…..” That was me..
Then a short vacation to hit the reset button so to speak…
In your comment about the RAW being tuned from the factory for supreme accuracy.
Just know, there are always people who will buy a brand new Bugatti, or a Ducati, or Ferrari, then start throwing money at it to make it. “better”.
Ian
45 Bravo,
But after spending lots of money on upgrades most don’t go on to do the most important thing and that is run the best Summer/Dry Season and Winter/Wet Season tires mounted on two sets of wheels for easy swaps.
shootski
Yep. I that the first “upgrade” I do for my cars. I really like Blizzaks for winter.
45Bravo: When it comes to shoes and especially purses, you would be shocked at what my wife is willing to spend. I used to react negatively to those purchases, but now that I am addicted to airguns, it seems like a good time to balance the books. ;o)
So true, I didn’t want to open the can of worms about purses…..
My wife has a similar addiction..
Many years ago we come to an agreement though, if the bills are paid, and all is said and transferred to where it needs to be, and there is money still in the account if you want it get it..
She earns it as much as I do…
Ian..
Yep. Same here.
Same deal here Bravo, …after all is paid.
We are finally (after years of scraping by raising a family) at that time of life.
Retired, kids gone, no mortgage, no debts and a quiet lifestyle leaves some extra money for new toys.
I’m double blessed that I can shoot in the backyard (125 yards) and my wife encourages my airgun addictions 🙂
Hank
My wife also supports my addictions.
When we got married for a wedding gift she bought me a 9mm UZI.
I knew then she was a keeper.
Ian.
Roamin Greco,
My Potenza RE-71R (Summer Slicks) are about to be rotated off my 9-3 Viggen and 9-5 AERO for the Blizaks for the next six months or so…got to get to the ski country to shoot and ski.
shootski
Bravo
That is one of the important things to know about pesting. Know the power of your gun and accuracy and the surroundings.
Pesting is way more harder then hunting or target shooting. If you never done it you will not fully comprehend. You have to be aware of alot of things and you better fully be aware of what is taking place all around you.
It’s intriguing and educational to be able to adjust all the variables in a gun, and see the effect. But truth to be told, it is mostly better if the optimization of the parameters has been conducted by a professional engineer, not by amateur me dedicating two hours spare time per month to airgunning…
Mel83,
There are many who should take that viewpoint that do not.
First, you should seriously learn to understand how an airgun works. Then you can start tinkering and learn what you should not have done.
I would encourage you to spend more time airgunning, if possible. :o)
BB,
Why do so many refuse to understand what you are saying here? Maybe if we relate to powder burners they might get the idea.
Yes, you can take a .30-06 and reduce the load to where you can shoot squirrels and not spread them all over ten acres, but why? Would it not be better to buy a .22LR for the squirrels and keep the .30-06 for the deer and such?
RidgeRunner, with you 100% *thumbs up* 🙂
Seriously. This is why I have low, medium and high power airguns. They are for different things.
There are some PCPs out there that you can adjust way down for plinking and way up for long range shooting or hunting, but most of the time you are going to have to re-zero the sight system because the POI will change.
A multi-pump can also do such, but most are not really that powerful and you still have the issue of POI change.
RidgeRunner,
Exactlly! Even with my old Sheridan, there was a wide variation in the POI depending on the number of pumps. It was advertised as “use 3 or 4 pumps for target use, and up to 8 for hunting,” but I found it much more accurate to use it at the sweet spot of 6 pumps, which gave me most of the power and also great accuracy. So I used it as a single-power gun, and it worked great on many animals for many years. Now, with the modern pellets, I find it to be great with JSBs at 7 pumps; so, once again it is back to being a variable-power-gun-used-only-in-single-power-mode, and it works fine that way. 🙂
Say “hi” to all the gals at RRHFWA,
dave
Lookie what I ran across yesterday.
/blog/2010/07/testing-the-hw-50s-part-3-2/
I had forgotten all about it.
BB,
My favorite system of adjustable power for non-regulated PCPs is the FX 3 position power lever. That gave me three repeatable power levels. I always liked the Crosman 180, Crosman Mk1, and S&W 78 with the half cock notch. I also like the half cock option on the Beeman P1.
David Enoch
DavidEnoch,
Agree. I like the 3 position power wheel on the FX guns. Had a cyclone and ranchero with these. I’ve had many pcp’s with an easy external power adjuster. My current favorite is a Kalibr Cricket mini carbine. It didn’t come with an external power adjuster but they’re readily available and I installed one.
What isn’t be talked about is keeping track of poi when you change power and/or pellet weights. It’s starts to get messy, especially with a pesting gun, to have several range cards or multiple markings on your parallax wheel for multiple velocities and/or pellet weights.
Good morning, B.B., this blog post reminds me of one situation where variable power may be needed, and 45Bravo touched on it above. Here is a fascinating article about the guns used to keep wildlife at bay at an airport. The author describes using an Airforce Talon SS to kill birds at close range inside an airplane hanger without putting holes through the metal walls and roof, but dialing up the power for longer range shots. The point RidgeRunner makes about having the right tool for the job is also addressed because they also use rifles for deer and shotguns when needed for passing shots at birds.
https://www.range365.com/guarding-an-airstrip/
This article should have been titled: “Roamin’ Greco’s Dream Job”
Thanks Roamin Greco for the link.
Your “..Dream Job..” would be my nightmare, yet when my time comes, I too would like to pass on without realising. So either in my sleep or a well placed sniper round (or similar) – but I’m in no hurry ! 🙂
Roamin Greco,
Although I agree with you that doing wildlife management jobs might be a “dream job” it has some downside if you need to do it in say Wyoming’s WORST OF WINTER WEATHER, or Texas and the res of the Gulf Coast in the HOT and HUMID season along with the bite capable flyers and the venomous snakes that are everywhere!
As far as the airfield I saw a really EFFECTIVE System at RAF Alconbury and a few other RAF airfields that used Falcons (the feathered kind) to keep the bird population out of the airplane operating areas. It was so cool to hear, “All ground operations hold position for Falconer Ops” and see the Falcons clear the air and return to their stands. The local birds soon learned that this was not a good area to try to setup shop and the passing through birds soon learned to move on NOW!
shootski
Hey everybody I know a good tunable air gun that most can use.
A multi pump.
But what one to recommend that is accurate even out at say 50 yards or so.
Umm let me see. Oh I got it. A 1322/77 with a steel breech and a Maximus barrel and a 1399 stock. Definitely a multi task gun. Problem is you got to build one if you want to see what they are all about. Oh but wait. The new Crosman Drifter is almost it. Maybe I should try one. 🙂
I think there is a “brave new frontier” in the world of adjustable airguns, and that is the new “hammerless” valve guns like the Huben K1. These use a sear to open a main flow valve, and a second valve to control the closing of the main air flow valve – there is no “hammer” involved in the process of opening the valve, and without the second valve controlling the closing, the main valve would act as a dump valve.
I bought one several months ago, and the adjustability is just crazy – and simple too, once you understand it. They have an externally adjustable regulator, so it is easy to adjust the regulated pressure on the fly, and they have a “power wheel” that controls the closing valve. So, you can think of it this way – the set point of the regulator defines the maximum power, and the closing valve allows you to lower the power from that maximum value easily and repeatably.
Mine is a .22 caliber, and I can easily set it to run heavy pellets or slugs at ~70 FPE, but that is not how I am using It – I am using mine as a normal pellet shooter at much lower energy levels. I have my regulator set at the low end of things, and thus the max power I am getting out of it right now is about 35 FPE, and my “main” or base setting of the power wheel has it shooting JSB 18.1 pellets right at an average of 900 FPS for ~32 FPE.
Anyways, I have tested this over the Chrony and I get a very consistent and easy adjustment between my 900 base tune down to a low (that I went to – maybe more is possible) of 285 FPS. The power wheel has “clicks” from detents in it that are 16 per revolution, and it takes only ¾ of a turn to get all the way down to that low point. So about 12 clicks gets me there, and they are not linear. But the ability to easily and repeatably select power across a full order of magnitude is very impressive. I have started a habit of walking outdoors with the gun set right at about 9 FPE in case I see any chipmunks close to the house (I am battling what amounts to an infestation), and then dial it back up before I start shooting at my spinners out at 45 yards.
When combined with the regulator set point, I can easily tune for (and then test for accuracy) at any individual average speed I might want to test – that is more involved than just twisting the wheel, as changes in reg pressure do take a few shots to stabilize, but the capability is there. If I leave the reg alone, I can easily alternate between shots at 900 and 285 FPS having a good ES for each subset of numbers.
Anyways, this kind of a system puts a big twist on what adjustability can mean to airguns.
Nice tip of the hat to the Beeman P-1. I concur with Tom G that the low power setting is usually not worth the effort. It changes the POI significantly. In my 10 M basement range, the impact is far higher than on high power. There is really no reason to use the low power given the shot consistency of the higher setting and the Champion trap will easily stop any pellet it throws.
The issue with this is the American, if not just plain human, tendency to want to tinker with things. I belong to an F-150 Face Book group and most of the posts are regarding “mods” to the standard Ford product. I raise, with futility, the point that the engineers might just know a whole lot more about balancing power, endurance, reliability and economy than an aftermarket aficionado. My commentary, of course, goes for naught as this has nothing to do with engineering sense – it’s about “tinkering.”
I confess that I tinker with my airguns, that are all springers or pumpers. My tinkering is with improved sights; putting on peeps or scopes and doing routine maintenance. So…I guess I’m one of ’em, but on a much reduced way. The good ting about our sport/hobby is that is significantly less expensive tinkering than pick up truck parts!
I think there is a “brave new frontier” in the world of adjustable airguns, and that is the new “hammerless” valve guns like the Huben K1. These use a sear to open a main flow valve, and a second valve to control the closing of the main air flow valve – there is no “hammer” involved in the process of opening the valve, and without the second valve controlling the closing, the main valve would act as a dump valve.
I bought one several months ago, and the adjustability is just crazy – and simple too, once you understand it. They have an externally adjustable regulator, so it is easy to adjust the regulated pressure on the fly, and they have a “power wheel” that controls the closing valve. So, you can think of it this way – the set point of the regulator defines the maximum power, and the closing valve allows you to lower the power from that maximum value easily and repeatably.
Mine is a .22 caliber, and I can easily set it to run heavy pellets or slugs at ~70 FPE, but that is not how I am using It – I am using mine as a normal pellet shooter at much lower energy levels. I have my regulator set at the low end of things, and thus the max power I am getting out of it right now is about 35 FPE, and my “main” or base setting of the power wheel has it shooting JSB 18.1 pellets right at an average of 900 FPS for ~32 FPE.
Anyways, I have tested this over the Chrony and I get a very consistent and easy adjustment between my 900 base tune down to a low (that I went to – maybe more is possible) of 285 FPS. The power wheel has “clicks” from detents in it that are 16 per revolution, and it takes only ¾ of a turn to get all the way down to that low point. So about 12 clicks gets me there, and they are not linear. But the ability to easily and repeatably select power across a full order of magnitude is very impressive. I have started a habit of walking outdoors with the gun set right at about 9 FPE in case I see any chipmunks close to the house (I am battling what amounts to an infestation), and then dial it back up before I start shooting at my spinners out at 45 yards.
When combined with the regulator set point, I can easily tune for (and then test for accuracy) at any individual average speed I might want to test – that is more involved than just twisting the wheel, as changes in reg pressure do take a few shots to stabilize, but the capability is there. If I leave the reg alone, I can easily alternate between shots at 900 and 285 FPS having a good ES for each subset of numbers.
Anyways, this kind of a system puts a big twist on what adjustability can mean to airguns. I am just getting to the point that I am very comfortable making those changes on the fly, and I’ll probably leave the gun shooting around 500 FPS or so for indoor paper punching over the winter (getting over 300 shots per fill as well).
Alan,
Interesting details on the K-1. Do you happen to know the electromechanical design in the various Daystate guns? Either with an external tuner or built-in like the Delta Wolf they must have an elaborate air control system.
Their rifles are not on my list or horizon. Just thought you might be able to satisfy curiosity.
jumpin
I don’t know about the new Delta Wolf, but the older electronic guns like the Air Wolf use what I would call an “Electromagnetic Hammer” to knock open a more conventional PCP valve. These hammers are able to be precisely controlled to hit the valve with the precise amount of energy needed to get the desired results based on the power wanted and the remaining air pressure in the reservoir. So every shot has a slightly different amount of hammer energy applied to get the desired results.
AlanMcD,
That is one of the better executions by a production company of the hammerless system using a spool valve system to control the charge. I wonder if their system could include a Plenum for better regulator(s) function?
Regardless it shows that major progress is still being made on Pre Charged side with more to come. Once the charge gets to and over the 10k psi watershed controlled by hammerless/springless powerplants we will see head to head competition with firearms of any kinetic potential. The thing(s) that will be the deciding factors will be the airguns micro controllable precision, environmental safety factors, none or comparatively soft recoil and cool operating temperatures that allow, scentless, near silent (subsonic) with virtually no thermal signature operation.
shootski
The Huben does have a plenum after the regulator. I have not had mine apart to measure it out, but I read somewhere that the plenum is in the ~35cc range. Apparently one can improve that simply by switching from the stock adjustable regulator to a more conventional Huma aftermarket one – it takes up less space in the plenum area leading to more plenum space. In doing so one gives up the adjustability of the stock plenum, but it is supposed to be more stable too. Others have reworked their guns with larger plenums for much more power, but the thing is a beast to start with (70FPE is easy in .22 stock – which ought to be enough, but the .25 can probably use more plenum for more power).
My Huben regulator is rock solid and I see no reason to swap it out so far. I have enjoyed playing around with the regulator and it is so easy to work on the gun that way – one can vent the plenum to take the action apart without draining the main reservoir. I can pull the whole action apart if needed (say, to pull patches through the barrel) and have it back together and back shooting in under 10-15 minutes, and the on-board air will have me shooting too without having to fully refill the gun from zero. It really is an amazing bit of kit . .
Wow. From the same country that gave us Gamo? There is hope for us all.
B.B.,
Thank you for this great Blog topic.
I think you may remember my concept of operations for my medium and Big Bores.
Determine requirement.
Select caliber
Select Kinetic Energy on target
Set and Chronograph
Determine actual containment ellipsis.
Determine if requirements have been met?
Yes, Go do it!
No, make appropriate changes repeat earlier steps as required.
Document, Document, Document
Buy more air and ammo….
One more time:
Thank You!
shootski