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burldude · New Member

I am new here and figured this would be a good place to start. I bought a crossman quest and noticed that I couldnt shoot it worth a darn. I blamed the gun , which propably had nothing to do with my lousy spring gun shooting. So I tore into it. I deburred every edge and opened up the airnozzle hole to just smaller that a pellet diameter. I then proceeded to hollow drill the front moving spring guide. I then cut away a notch on top of the metal piston assembly almost equal in length and width of the cocking notch on the bottom side. I now had the gun spitting pellets out at supersonic speeds. But the accuracy still wasnt there. Some would shoot high some would shoot low. I then mounted a tasco airgun scope on the gun only to have it walk backwards. My fix was to mig weld two stops on the end of the sight rail (dovetail). Which I then cleaned up with a dremmel. It still wouldnt shoot straight, so I used a pencil chucked in a dewalt drill with the end shaped to just barely fit in the crown. I dipped the pencil in polishing compound (turtle wax will work) and ran it on the crown of the barrel just till is started to be polished. Trying not to work to far into the riflings. I then polished the inside of the piston cylinder with 800 grit sand paper that was wore out to around 1500 grit. Stilll the accuracy wasnt there from shot to shot it would sound differnt and it wasnt dieseling. I took it apart again and looked at the piston rubber. It has an expansion groove in it that is a circle. I took my exacto knife and being very carful cut the groove wider cutting away some of the rubber from the center. I made the groove about twice as wide with a slight chamfer to the inside center. I went out and shot it late last night and with beeman silver airrows and the gun zeroed at 20 yards I was aiming 6 inches high at 75 yards hitting a can repeatedly. The shot consistancy is there now every shot sounds the same. I am sure I can get 1.5"groups at 50 yards. With target pellets I am running about 1100 fps and the silver arrows are just heavy enough to not go super sonic. I havent yet tackled the trigger but I am sure that will be next. Hold it loose as can be...... It took me 1000 pellets to "tune test" and figure it out. Maybe a thrust bearing on the back spring guide or a recoil slide like on the rws 54. Anyone know where I can find a differnt main spring or one made of titanium?

AirGunEric · Site Admin

Maccari has (had?) springs for the Quest/Phantom/B1x guns- and they are very good. Don't know about titanium units, however.

Anyways- expanding the groove in the valve seal tightened up your groups? What does this imply- that the factory seal was not sealing properly as it was too rigid and some sort of turbulence was causing pellets to go askew? I'm trying to follow how this helped accuracy(?). Sounds interesting, but I'm having a tough time relating one to the other.

But- glad you got the issue sorted out. You might want to think about a couple of thrust washers as opposed to a bearing. Bearings tend to grind away and fail in spring environments- but a couple of lubed washers rubbing together won't leave too much crud to float around in the tube where a broken bearing might.

Post some pics of your changes- if you can.

And, Welcome to AirGunHome.com!

burldude · New Member

The factory piston rubber is very rigid. I dont know what else to compare it to though. The groove in the top is supposed to allow pressurized air to cause the piston rubber to expand and enlarge in diameter ever so slightly to provide a more adequate seal. The factory groove is to narrow to allow the pressure to build quick enough to ensure a consistant chamber pressure. I have a barn that I can shoot in, just over 10 yards. Tonight I was shooting very carefully into foil covered insulation. I kept aiming at the tip of this star printed on the foil. I couldnt understand why I was having so much trouble finding my shots. I shot 3 shots and walked over to it and stuch my finger against it and relized I had put all 3 in the same hole. I stuck my finger against the foil and kind of changed the shape a little. I went back to my bench and put two more shots throught the same hole. I couldnt beleive it so I started another group and did the same thing and still couldnt believe it, so then I stuck a golf tee in the hole and took one more shot and split the tee down the middle. This is with a cheap walmart tasco spring gun scope. I dont even want to mess with the trigger now. I am on dial up so I will have to post pictures in town tomorrow

AirGunEric · Site Admin

I understand what you're saying- but I'm still having problems trying to equate poor valve sealing to poor accuracy. The power level would be lower with a seal not doing it's job properly- quite likely resulting in a drop in the POI vs. POA over greater distances- but at 10m/30ft I'm not sure how this would matter. Anyone have any ideas?

burldude · New Member

I can equate it to the spin imparted by the riflings. Also by not having a consistant piston seal the pellet will exit the barrel at differnt times of piston travel. Depending on how the spring has twisted during the cocking firing sequence will determine the seal quality of the piston to chamber. If the piston seals at the innitial forward travel it will reduce the amount of variables. Check out this group at 12 yards. I had a hit on a beer can at 89 full grown paces last night off hand. The golf tee was sure a suprise.

Just above the tip of the star is where the five rounds where placed. I had the front forearm of the stoc resting on a wadded up bdu jacket and the buttstock on the same table with one layer of bdu under it. This allowed the gun to slide and recoil freely. To get a group like this I had to check my paralex around 15 times a shot with the cheap tasco scope. But compliments to them for making a 25 dollar scope that can stay zeroed.

I was once a US Army Ranger Sniper, 14 years ago.

burldude · New Member

Well my spring is sprung with no shimming or binding just 2000 shots some in rapid sucession. Here is a picture of my piston with weight cut away. I noticed the spring bent the first time I took it apart. I didnt have it shimmed. I also recut my sear last night and polished all contact points I can adjust my my trigger pull from 1/4 to 1/16" travel. It is set to about a 1.5 lb trigger pull. I tried bouncing it off the butt pad to get it to misfire but it wouldnt. The piston rubber looks so much better after 500 shots put through the polished chamber. When I first pulled the piston out it had all sorts of gouges in it. I need help finding the best spring/piston for it now.

22magnum · Member

.. opened up the airnozzle hole to just smaller that a pellet diameter. I then proceeded to hollow drill the front moving spring guide. I then cut away a notch on top of the metal piston assembly almost equal in length and width of the cocking notch on the bottom side.

I have slower Phantom's 0.22 but am interested in any further mods I could do for power and accuracy..do you or any one else know any % V increases for these mods? I have never heard of the airnozzle hole enlargement as a mod? and to be honest ,I need someone to explain the extra slot on top of the piston..lower mass of the piston? Help ! I have two Phantoms in the basement waiting for proper re-lube and I need more projects ! I am getting complaints on the repeatability on the gun from my SFIL who has shot his more than mine...could be just grip but I would be interested in learning more..Paul

burldude · New Member

I cut the slot to lower the mass of the piston. I am looking into purchasing some titanium tube and make a thinner Titanium piston weighing a quarter of the stock one. More fps and less intial inertia moving point of aim. The air nozzle I opened up to try to decrease dwell time. This is the time it takes for the projectile to leave the barrel after the trigger has been squeezed. More air flow means the piston will not have as much of a cushion of air as it hits its forward travel limit causing more shock. But if an optimum balance is found between piston weight and piston seal there can still be substantial cushion. I am looking into making this quest into a competitor vs the rws model 54. I had a hit this morning on a can freehand at 105yards plus. 10 shots later It broke. Iam currently looking into the tarantula spring.

broommaster2000 · Moderator

Well, good luck with that.

22magnum · Member

burldude · New Member

I got a new Maccari spring. I was used to the stock spring being easy to remove and compress by hand. Wow was this thing hard to compress. I wish that is stayed that way Just above stock tension after around 40 shots. But the first couple shots where awesome. I purchase the titanium for the piston should be here today. Now I just have to have it welded and machine some grooves. Really easy stuff and the titanium cost like 25 bucks. Should give me a big increase in power. I think I will open up the air nozzle to full .177 diameter with these heavy pellets they need to get moving sooner than the 6.5g lightweights the hole was designed for. Maybe I should drill and thread a cross whole into the air nozzle to control air flow. Like a t fitting. this way the rifle could be tuned to acheive optimum fps and recoil reduction. I think this would be a great feature.

AirGunEric · Site Admin

The Maccari springs come un-set- so the first shot or two are usually unbelievable- then the spring sets and you're where the guns going to stay, give or take.

BBGun Bob · Veteran Member

Having built one of the most powerful and accurate 1000X Quest's in Michigan with the help of Rich in Michigan,Jim Macarri and reading Todd Cooper's how to on Quests& Phantoms you have pretty much ruined that Quest.
The reasons are as follows,When you open up the transfer port(airnozzle) as you call it,and lighten the piston you change the lock time.Lock time is measured in milliseconds.A Quest takes 8 milliseconds to complete a fireing cycle.You have increased the speed of the piston so that it is now full forward before the pellet leaves the barrel,also you have piston slap at the end of it stroke because there is little or no resistance to slow its forward travel down enough to give proper lock time.All these equations of motion are figured out by engineers with the weight of the piston,spring tension,lenght of stroke,chamber dia.,barrel dia ,transferport dia.,and bore.
What is happening is your rifle is now recoiling just before the pellet leaves the barrel.In more ways than just forward and back.Because you lightened the piston you have lost a lot of kinetic energy which is also figured out by engineer's in making the equations of motion. So now you have added a new type of recoil to your rifle by creating more uncontrollable torque .As your light piston flys forward during your to short of firing cycle it is uncoiling at the same time causing your rifle not only recoil back and forth but it now twists to the right or left depending on which way your main spring is wound.This is all happening just before your pellet exits the barrel probably in less than a fraction of millisecond in real time.You have no control at this point because you don't know exactly where your point of aim really is!
A Crosman Quest has one of the longest strokes of all break barrel springers.You can tell this by how far the barrel moves before it is in full cocked position.Most break barrel spingers when cocked stop when the barrel is about 90 degrees from the stock.A Quest goes to almost 145 degrees.
The 1000X Quest I built(With Pride) now has a Lother/Walther .20 caliber barrel,a Macarri Arctic RWS 350 Spring,the trigger breaks @ 125 grams not pounds.It will fire.20 caliber 11.45gr. Beeman Field Target Specials (FTS) pellets at 923-928fps @18-21fpe. consistantly! The scope is a Baraka Varmint 6X24X42 with BKL single mount and 2 scope stops.If benched it will shoot thru the same hole at 100 feet or 35 yards.
You must remember pellet speed is only good until it reaches the sound barrier.The magic pellet speed number in any pellet rifle is between 900fps to 950 fps. Because pellets are too light no matter what caliber. They lose all ability to fly right/straight once they go supersonic .The shock wave created by the breaking of the sound barrier will throw a pellet off it flight path every time.So you may have a gun the shoots at 1500 fps but you ain't going to hit sh!t with it because of the turbulence created around the pellet when breaking the sound barrier .
My reason for building this Crosman 1000X Quest was to see if I could make it better than the very expensive RWS,Weihrauch and Beeman rifles.I have over $250 in it but it is a bad M'r F'er and will shoot with the best of them.

I hope this little read will help you
master your Quest.
You need a new piston(more weight/not less)
and reduce your Dia. in transport to
.125-.187max to get proper back pressure
in your charging chamber/stops piston slap
This will correct lock time.

Sincerly
BBgun Bob
1000X Quest Master LOL

AirGunEric · Site Admin

I believe burldude tried to address some of those issues by lightening the piston- although the idea of changing the piston to something of a lighter weight overall might be the best course of action. If the gun in question were a Diana or a Weihrauch or something, I'd think the engineers probably got things designed fairly precisely- but on a Chinese-made springer I wouldn't lay too much money on the precision of the factory engineering, myself.

BBGun Bob · Veteran Member

Inertia and Mass

Newton's first law of motion states that "An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force." Objects tend to "keep on doing what they're doing." In fact, it is the natural tendency of objects to resist changes in their state of motion. This tendency to resist changes in their state of motion is described as inertia.

Once he has lightened his piston and added more spring force he has indeed changed his inertia which also changes the kinetic energy and lock timing. Once this change is made all the forces I mentioned above are out of control to which they were originally designed.Whether Americans or Chinese did the first design.They still have to follow certain specifications when building a air rifle.It is fairly well known you gain 50-75 FPS by making the transferport smaller in most Chinese rifles.And also add weight to piston to increase inertia when a stronger spring is added!! ?? Yes? NO?

Later going to watch the NASCAR Race.

BBGun Bob