Custom spring?

[Petar]

Hello everybody,

I need advice with custom spring for air rifle.
Is it possible to put new more powerful spring (1000 FPS) into weaker air rifle with 560 FPS?
Will that increase power?

Every comment is welcome

[K_sqrd]

From what I've read, you get the most increase in power by increasing the swept volume of
the compression tube. Though you may get some increase by changing out the spring, going from
the mid 500's to 1000 FPS is doubtful. The firing cycle will also become more harsh and the gun
will require more effort to cock. Piston weight also plays into the mix and can affect the outcome.

[nced]

Hello everybody,

I need advice with custom spring for air rifle.
Is it possible to put new more powerful spring (1000 FPS) into weaker air rifle with 560 FPS?
Will that increase power?

Every comment is welcome

Piston guns are all about "balance" between spring strength, spring preload, swept volume and pellet weight! Years ago I bought a heavy wire Maccari Steelgate spring and installed it in my R9 in an attempt to get 800fps velocity with a 10.5 grain heavy pellet using the old design HW factory piston seal. I never achieved 800fps but I did get 790fps with a tooth rattling harsh shot cycle scope wrecking shot cycle. After a shooting session I accidentally put the gun away cocked for two days. The next time I shot the gun I realized that the gun had been cocked for two days and after shooting the "stored pellet" I noticed that the gun cocked noticeably easier but the funny thing is that the R9 with the weakened spring was shooting the 10.5 grain heavies 5 fps faster at 795fps. I also noticed that the heavy spring shot a 7.9 grain pellet only 30fps faster than the factory spring, however the heavy spring shot 10.5 grain pellets 50fps faster than the factory spring.

Anywhoo.......decades ago I nixed the heavy spring in favor of a lighter spring that would shoot a 7.9 grain pellet at 910fps which I used for years. A few years ago I even started installing a lighter spring in my R9 that gives me a 7.9 grain velocity of about 850fps.

IMHO......with normal weight springers slower can be better! LOL......using a 30 yard zero a .177 cal CPL pellet with 810fps at the muzzle drops less than 1" more at 50 yards than the same pellet with 910fps  at the muzzle. The midrange rise is a bit higher with the 11.5fpe tune than the 14.5fpe tune.

[phoebeisis]

From a strictly "sensible" and "dollars and cents" point of view
the BEST way to make your motorcycle  car     gun "faster/better" is to sell it and
buy a faster from the factory machine
ALWAYS works out better-always cheaper-
But TINKERING is fun-so if tinkering is your main motivation-have at it-
luck
charlie

[Hobbyman2007]

Knowing what model air rifle your working with would also help. If you have detuned ( Canadian) model rifle , then yes a spring change is all that is required most of the time . If you have a youth model air rifle and try jamming a huge spring in it to gain pellet speed it simply won't work , as mentioned above ,swept volume and spring balance is the key.

[Petar]

Hello guys and thank eveyone for help.
I'm planning to buy Crosman Phantom (630 FPS).
I contacted guy who told me he may have parts for it in his stock.
PS
can somebody explain me what is and how do i ''make'' swept volume and spring balance?
Is that something that i can do myself or do i need gunsmith?

[K_sqrd]

Swept volume is the volume of of air contained in the compression tube from the front of the piston seal
to the end of the compression tube when the gun is cocked. It's part of the initial design of the
airgun when manufactured so changing it would be quite difficult (impossible) and probably not worth the effort.
When an airgun is designed, it is usually built to perform best in a range near the upper end of it's
design specs. So changing to a different spring to get more power usually results in negligible gains
because the AG is near it's max output already. The best way to get more power is to buy an AG designed
for what you want in the first place.

EDIT: It looks like the Crosman Phantom is advertised as a 1000 FPS unit. Therefore a new spring may
         bump the speed up a considerable amount. Let us know how it works out.

[phoebeisis]

Petar
Check with Sanjin(OXYGUN) before you buy that under powered Crosman Phantom
You will find him on the German Gate-
You probably already have run across him on this forum?
he is in Zagreb/Croatia also -big city,but computers make you a click away
He is very knowledgeable about all things air gun-and gun guns-has Diana 31/34   and Diana 350(a true magnum .177-much more powerful than the claimed 1200 fps crosman phantom)
He might be able to steer you to a  local  or EU dealer with decent prices-
Here is a walmart blurb on the Crosman Phantom here USA-
like K_sqrd says    -much more than 650fps here




The Crosman Phantom .177 Break Barrel Carbine has an all-weather stock with ambidextrous design and a two-stage, adjustable trigger. With a relatively light cocking force, the Crosman .177 Break Barrel Carbine has a micro-adjustable rear sight and fiber optic front sight. The Crosman pellet guns have a velocity of 1,200 fps (with lead-free pellets) and are made of synthetic materials. This Crosman .177 Break Barrel Carbine is a superb pellet gun that would make a great gift for the outdoorsman in your family.

[Petar]

Petar
Check with Sanjin(OXYGUN) before you buy that under powered Crosman Phantom
You will find him on the German Gate-
You probably already have run across him-
he is in Zagreb/Croatia also(maybe actually a suburb of zagreb)-big city,but computers make you a click away
He is very knowledgeable about all things air gun-and gun guns-has Diana 31/34   and Diana 350(a true magnum .177-much more powerful than the claimed 1200 fps crosman phantom)
He might be able to steer you to a  local  or EU dealer with decent prices-
Here is a walmart blurb on the Crosman Phantom here USA-
like K_sqrd says    -much more than 650fps here

Thanks for info.
I'll contact him on German Gate like you said.
It's weird i don't know him,because Zagrebi ain't that big



The Crosman Phantom .177 Break Barrel Carbine has an all-weather stock with ambidextrous design and a two-stage, adjustable trigger. With a relatively light cocking force, the Crosman .177 Break Barrel Carbine has a micro-adjustable rear sight and fiber optic front sight. The Crosman pellet guns have a velocity of 1,200 fps (with lead-free pellets) and are made of synthetic materials. This Crosman .177 Break Barrel Carbine is a superb pellet gun that would make a great gift for the outdoorsman in your family.

[phoebeisis]

Petar
Maybe he is actually in a suburb of Zagreb?
Or maybe I have it mixed up-?
In any case Sanjin/OXYGUN is a Diana and "real guns" fan-
He most certainly will sing Diana/RWS praises
so would I
I like my 460
but it needs to be lighter-maybe I will make the cocking handle removable-9 3/4 lbs with scope-I shoot standing free hand-don't hunt just targets and self defense practice(firearms readily available here)-but mostly just fun shooting in the hallway)
anyway I am going to make it lighter-so pretty but a lot to be said for light-and I like to tinker-

Oxygun/sanjin  deals with a firearms-and air gun dealer I guess -that places BULK orders-waits until he has 10-20 orders-then places a big order-saves shipping-and perhaps customs  tax issues-
anyway he has navigated the regulations for a real firearm-nice .22 LR CZ HB rifle-target small game hunting-apparently even .22lr-require some legal licensing to own-
maybe that crosman would response to "just the spring" since it is a neutered MUCH more powerful gun-a much weaker spring would be an easy way to makes regulatory limits on joules or foot pounds energy -
normally on a full powered gun-would only increase the velocity a little-adding some kinetic energy-raising the temperature of the chamber-but not much since the full powered springs reach the breech in just 1/100 second-almost exactly when the pellet leaves the barrel-hard to get much faster-a little more  PEAK pressure-hardly matters-the average pressure for the time-would be just a tiny bit higher-so not much more velocity-the earlier peak pressure would just break the pellet loose earlier- normally it breaks loose at 8/1000 seconds-according to paper posted on forum

[mactoast]

Hey Petar,

I just went through upgrading my Canadian model Phantom to a full power version. Well worth it in my opinion. That being said I would just buy a full power gun from the get go if that's what you want. I screwed up and didn't know what I was getting. It was an easy upgrade and fun to learn about the inner workings of the gun.
Read this thread for what I did.
newbielink:http://www.gatewaytoairguns.org/GTA/index.php?topic=103555.0 [nonactive]

[phoebeisis]

It is too bad Petar can't order from USA
Customs-duties-taxes-or just gun legal stuff-mean he can't/
Currently Midway has a
Crosman Phantom NP .22 for $69.95+ SHIPPING
It is actually $79.99 But with a $10 mail in rebate
so too my door-near New Orleans I could get one for\
$80+$13 shipping=$93 - $10 rebate=$83 for a rifle that claims 950fps with .22 pellets
Checked online with full 14 grain pellets it is  750 fps
Walmart has a similar Nitrogen piston rifle $100+ tax-
Not long ago Amazon had a M34 wood-for $170+ shipping-roughly what Petar is paying from the  used HATSAN


On the other hand in the USA we get screwed on Pharmaceutical prices-and medical costs in general- guess the grass is always greener other side of fence
but we have great gun prices!
Charlie