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All Springer/NP/PCP Air Gun Discussion General => Air Gun Gate => Topic started by: D14Jeff on August 24, 2014, 08:19:54 PM

Title: detuning magnum springers to medium power ???
Post by: D14Jeff on August 24, 2014, 08:19:54 PM
FWIU given the SAME or very similar FPE power plant ... the heavier a springer/break barrel pellet gun is the less recoil is a factor ... typically ..... but not written in stone .
and FWIU wood stocks typically mitigate recoil better than plastic ones .

with those thoughts in mind ..... will taking magnum metal spring air guns guns like the xs28m , rws 350 and hatsan 135 in .22 cal. and cutting enough coils off the spring to get them down to 700 to 800 FPS (similar to their smaller xs25 , rws 34 and hatsan 95 siblings in .22 cal.) allow them to generate less recoil and be less hold sensitive ? i really want to try a springer again , i tried a trail NP all weather a few years ago for a week and took it back because i just couldn't get good accuracy from it ... probably due to the recoil . it was also very very front heavy and that made it feel very awkward to hold IMO . my thinking is detuning a magnum wood stocked springer would help with both the balance a whole lot and and reduce the recoil to make a easier learning curve learning to shoot it . am i onto something here ? or am i simply wrong ? i think it would also be pretty cool that when i do master shooting it (aka the artillery hold) that a simple $20ish dollar spring will give me the chance to make a significant jump in power/shooting distance if i have the space or desire to .

all thoughts/suggestions are appreciated . :)
Title: Re: detuning magnum springers to medium power ???
Post by: ptpalpha on August 24, 2014, 08:37:57 PM
Short answer: yes.  If you take an XS28 for example, remove the oem spring, replace it with a softer spring of the same o.d., you will experience a decrease in fps, fpe, and perceived recoil.
To do this you'll need to determine the wire diameter of the oem spring (probably .128), set length, and i.d. and o.d.
Replace it with one that has a smaller wire diameter (like .120), same or slightly shorter set length, and same i.d. so you can use the oem guides.
Another way is to remove a coil or two from the oem spring, and make tight fitting delrin spring guide and tophat.  Remove the oem metal spring sleeve and replace it with one made from HDPE (or use the plastic "coke bottle" method).
Make sure to use quality lube products (i.e. Maccari) and give the spring a light coating of heavy tar.
I seem to remember that Vortek offered a "soft tune" spring for the XS28/RWS 350 that gave the performance you're describing.  Might be worth shooting an email to Tom at Vortek.
Title: Re: detuning magnum springers to medium power ???
Post by: TC on August 24, 2014, 09:37:52 PM
Detuned a Stoeger X20S from 15+ to 12+ foot pounds for improved bench resting precision. Lost 20% in fps but did indeed achieve less shot action and hold sensitivity. More precise at 40 yards with less power. This was accomplished by using a stock spring and cutting off a few loops at a time until I reached ~12 foot pounds. Next I will try a non stock spring made from thinner wire (.120" vs .128") to see if it is possible to settle it down even more. Why wouldn't similar physics to apply in your situation (magnum to a medium)?
Title: Re: detuning magnum springers to medium power ???
Post by: lillysdad621 on August 24, 2014, 09:49:43 PM
they do, but you may also try to find a better suited pellet weight for the spring you got... IE. i got a big cat over the weekend (freebie) that i lube tuned and was at the end shooting 7.9 CPhp at 860 fps... i tried to shoot 10.5 and they only went 715 fps... that is a huge drop... that was after a lube tune and a entire clean up. gun shot a lot smoother with the heavies and it groups much better (.466) at 20 yards. The spring i put on was an older vortek spring that i had laying around... a bit shorter than the original... but the wire seemed wider... I am happy to shoot this gun at 11.8 fpe...
Title: Re: detuning magnum springers to medium power ???
Post by: AudiS4 on August 25, 2014, 04:00:58 PM
The XS28, is already at the same power level as the 95, so the only magnum is the 135 of your selection.

If you need to alter a magnum, then you can already get a medium powered gun from the get go, and then you are down to about 20-25 fpe. That is where the XS28 and a Hatsan 95 are as standard. 135 is 30+ fpe. Just tune a 95, and get a Vortex piston, then youŽll have a 20+ fpe gun, that is smooth and accurate, and doesnŽt weigh as much as the XS28 and 135.
Title: Re: detuning magnum springers to medium power ???
Post by: Petey on August 25, 2014, 05:45:22 PM
Do IT! it's worth it .....but knocking one or two coils off the spring wont' do much....4 and proper fitting guide will get you in you in the neighborhood....or get Tom at Vortek or JM to make you a 12 pound kit...

I have a JM custom 12 pound kit in my 48...love it.
Title: Re: detuning magnum springers to medium power ???
Post by: LAalex on August 25, 2014, 08:49:32 PM
Do IT! it's worth it .....but knocking one or two coils off the spring wont' do much....4 and proper fitting guide will get you in you in the neighborhood....or get Tom at Vortek or JM to make you a 12 pound kit...

I have a JM custom 12 pound kit in my 48...love it.

This is where I would go.

Scotty
Title: Re: detuning magnum springers to medium power ???
Post by: angrytimes on August 25, 2014, 09:29:07 PM
conservation of momentum. decrease the velocity or increase the mass and it will kick less.
Title: Re: detuning magnum springers to medium power ???
Post by: lillysdad621 on August 25, 2014, 09:29:16 PM
a 48 in 12 fpe... that must be heaven... i like short heavy rifles in 12 fpe... they shoot so well
Title: Re: detuning magnum springers to medium power ???
Post by: angrytimes on August 25, 2014, 10:05:12 PM
I dont really get what the deal is with magnums though... I have only shot a few air guns (gamo big cat, cfr, cfr igt, tx200 and diana 52) and my mates 52 is just as easy to use as my tx200. We were both hitting a plastic bottle at 100m (prone) and swapping guns and I couldn't even really notice any more recoil as my set up is slightly heavier. His 52 is no doubt more powerful than my gun but it does not seem harder to shoot with
Title: Re: detuning magnum springers to medium power ???
Post by: lillysdad621 on August 25, 2014, 10:12:18 PM
the deal is when you split the skull on a 28 lb raccoon at 40 yards and it just stops moving... 1 shot. (2007, theoben eliminator, .22 cal kodiak, about 840 fps for a sweet, unadultered and very civilized 33 fpe.). sometimes it is absolutely necessary. when you can get a gun that is sorted and pushes over 25 fpe, its nice... otherwise they are vibration monsters...
Title: Re: detuning magnum springers to medium power ???
Post by: Petey on August 25, 2014, 10:57:46 PM
the deal is when you split the skull on a 28 lb raccoon at 40 yards and it just stops moving... 1 shot. (2007, theoben eliminator, .22 cal kodiak, about 840 fps for a sweet, unadultered and very civilized 33 fpe.). sometimes it is absolutely necessary. when you can get a gun that is sorted and pushes over 25 fpe, its nice... otherwise they are vibration monsters...

 LMBO! ....LOVE IT!

I have two set ups for my 48.. the JM soft kit and one I made myself that shoots JSB 8.44 at 985 and is smooth as heck. Best thing is I can swap kits on a whim and takes maybe 20 minutes to do so....48s are a great thing .

Happy Shootin To All!
Petey.

(http://i1193.photobucket.com/albums/aa347/NPetey/48/IMG_0634_zps020d858e.jpg) (http://s1193.photobucket.com/user/NPetey/media/48/IMG_0634_zps020d858e.jpg.html)
Title: Re: detuning magnum springers to medium power ???
Post by: mista meener on August 25, 2014, 11:45:39 PM
the deal is when you split the skull on a 28 lb raccoon at 40 yards and it just stops moving... 1 shot. (2007, theoben eliminator, .22 cal kodiak, about 840 fps for a sweet, unadultered and very civilized 33 fpe.). sometimes it is absolutely necessary. when you can get a gun that is sorted and pushes over 25 fpe, its nice... otherwise they are vibration monsters...
What an accomplishment. To me all springers have one way they like to be held magnum or not. if you want a springer that shoots a certain velocity just buy one. many shoot 550-700 fps or slower or faster. easy to pick one. why buy a magnum and detune it?
Title: Re: detuning magnum springers to medium power ???
Post by: Dick Tracey on August 25, 2014, 11:46:06 PM
I know you are talking about Springers here, but my thought would be to get a 135 with Vortex gas ram.  I believe you can change the pressure in the ram.  That way you can tune to what ever level energy you want and don't have to mess with springs.

DT
Title: Re: detuning magnum springers to medium power ???
Post by: Petey on August 26, 2014, 12:40:08 AM
the deal is when you split the skull on a 28 lb raccoon at 40 yards and it just stops moving... 1 shot. (2007, theoben eliminator, .22 cal kodiak, about 840 fps for a sweet, unadultered and very civilized 33 fpe.). sometimes it is absolutely necessary. when you can get a gun that is sorted and pushes over 25 fpe, its nice... otherwise they are vibration monsters...
What an accomplishment. To me all springers have one way they like to be held magnum or not. if you want a springer that shoots a certain velocity just buy one. many shoot 550-700 fps or slower or faster. easy to pick one. why buy a magnum and detune it?
You have much to learn Grasshopper. ;)
Denying yourself the pleasure of ownership simply because an AG has more power than you need is senseless.  Simply de-tune and enjoy many hours of pleasure.........learning how to tune has many benefits.
Don't get caught up in the power game........a sub 12 pound gun can do many things very well....taking a magnum and  taming it is good thing.
 Those who have traveled the path understand.
Happy Shootin!
Petey
Title: Re: detuning magnum springers to medium power ???
Post by: angrytimes on August 26, 2014, 02:37:31 AM
you misunderstand me. I mean what is the deal with them being difficult to shoot? I get that more power = more killing ability but I did not think the 52 was any harder to shoot than the tx. In saying that my tx will put a pellet through a sheep skull at 40m (tested bounced off and just cracked it at 45) so I do not think that a few extra fpe is a big deal. especially when there is this thing called a firearm. 15fpe, 20 fpe, 30 fpe, 2000fpe...
Title: Re: detuning magnum springers to medium power ???
Post by: D14Jeff on August 26, 2014, 06:20:41 AM

I have two set ups for my 48.. the JM soft kit and one I made myself that shoots JSB 8.44 at 985 and is smooth as heck. Best thing is I can swap kits on a whim and takes maybe 20 minutes to do so....48s are a great thing .


good to read :)
i'm just thinking about ways to insure that if i get a springer that i'll enjoy it and won't have buyers remorse like i did with the trail NP all-weather i tried . i'm not worried about weight or the length of the airgun cause i don't hunt . my little DBO/2289 is fine for annoying birds and with it's mods will be plenty for rabbits or squirrels if i did want to hunt . i keep wanting to try something different , PCP is too expensive and i don't care for the temp issues Co2 has .... so that leaves break barrels and under/side levers . i'm scared of under/side levers because i've seen a few very nasty pics of fingers mauled by them ! i know it's very very rare but (for myself) i feel it's a unnecessary risk .

i should probably just get a cheap wood airhawk or refurb 95 or a xs25 from MM ... but that 135 is just BEAUTIFUL with its turkish walnut stock ! and it's made with a better grade of steel plus the quattro trigger is supposed to be very good with the addition of longer adjustment screws . i'm prone to over think things sometimes and it get's me into analysis paralysis . i can't get anything for a few months anyhow so i've got plenty of time to muddle my way through it .

i thought i'd be satisfied with just my pumper , but i want something different and the pumping does get old/tiring at times . at some point i'll post to see if someone in my area would let me watch them tune a break barrel or two if i bring a few 6 packs of their prefered brew for putting up with me , hehe . i love to tinker and even though i think my reading comprehension is at least average , seeing something with my own eyes instills more confidence to do something . i'm thinking that getting a BIG springer and detuning it gives me a better chance at shooting accurately and being more comfortable with it ...... and getting a full power spring later to see how i like it . the equipment to change a vortex gas ram cost too much , a extra spring (or two) and some tar is much cheaper . a spring compressor is cheap and easy to make with a big C-clamp and some 2x4s .

sorry if i'm a pain in the butt , but i am what i am :)
and thanks for all the replies ;)

did i mention that the 135 is absolutely beautiful !!! 8)
Title: Re: detuning magnum springers to medium power ???
Post by: mista meener on August 26, 2014, 09:16:11 AM
the deal is when you split the skull on a 28 lb raccoon at 40 yards and it just stops moving... 1 shot. (2007, theoben eliminator, .22 cal kodiak, about 840 fps for a sweet, unadultered and very civilized 33 fpe.). sometimes it is absolutely necessary. when you can get a gun that is sorted and pushes over 25 fpe, its nice... otherwise they are vibration monsters...
What an accomplishment. To me all springers have one way they like to be held magnum or not. if you want a springer that shoots a certain velocity just buy one. many shoot 550-700 fps or slower or faster. easy to pick one. why buy a magnum and detune it?
You have much to learn Grasshopper. ;)
Denying yourself the pleasure of ownership simply because an AG has more power than you need is senseless.  Simply de-tune and enjoy many hours of pleasure.........learning how to tune has many benefits.
Don't get caught up in the power game........a sub 12 pound gun can do many things very well....taking a magnum and  taming it is good thing.
 Those who have traveled the path understand.
Happy Shootin!
Petey
Again why buy a magnum rifle so you can go thru the trouble and work to detune it when you can buy a German rifle that shoots at the desired detuned level out of the box. if you do not want magnum velocity don't buy a magnum
Title: Re: detuning magnum springers to medium power ???
Post by: Paul68 on August 26, 2014, 09:38:58 AM
Keep in mind, the big magnums also have heavier piston assemblies, so even though you lower the spring power and get the gun putting out FPE similar to its little brothers and sisters, it will still have more recoil even with the slightly heavier body. Springers are a balancing act, and everything is built to work as a part of the whole. The better route is to put that effort into smoothing and tuning. I've had many big springers, and I treat em just like their smaller siblings; if they cant do a dime or better at 25 yards, they need work. I've had the magnums doing under an inch at 50 yards, so to me, reducing the power in one is really counterproductive and taking away from the potential the gun was designed to provide in the first place. Just get a gun already at the power level you want, and choose a model with  a rep for accuracy. The 48's and 52's for instance are perfect candidates. Powerful, low hold sensitivity, and very very accurate.
Title: Re: detuning magnum springers to medium power ???
Post by: mista meener on August 26, 2014, 10:26:26 AM
Keep in mind, the big magnums also have heavier piston assemblies, so even though you lower the spring power and get the gun putting out FPE similar to its little brothers and sisters, it will still have more recoil even with the slightly heavier body. Springers are a balancing act, and everything is built to work as a part of the whole. The better route is to put that effort into smoothing and tuning. I've had many big springers, and I treat em just like their smaller siblings; if they cant do a dime or better at 25 yards, they need work. I've had the magnums doing under an inch at 50 yards, so to me, reducing the power in one is really counterproductive and taking away from the potential the gun was designed to provide in the first place. Just get a gun already at the power level you want, and choose a model with  a rep for accuracy. The 48's and 52's for instance are perfect candidates. Powerful, low hold sensitivity, and very very accurate.
does that rws 350 shoot 1/2 inch at 50 yds? that is PCP accuracy. plus detuning a magnum rifle you end up with a heavy 12 fpe rifle when there are many very accurate springers stock that are lighter and  at 12-15 fpe. it is like turning 4 wheel drive truck into 2 wheel drive
Title: Re: detuning magnum springers to medium power ???
Post by: Petey on August 26, 2014, 12:11:48 PM
Keep in mind, the big magnums also have heavier piston assemblies, so even though you lower the spring power and get the gun putting out FPE similar to its little brothers and sisters, it will still have more recoil even with the slightly heavier body. Springers are a balancing act, and everything is built to work as a part of the whole. The better route is to put that effort into smoothing and tuning. I've had many big springers, and I treat em just like their smaller siblings; if they cant do a dime or better at 25 yards, they need work. I've had the magnums doing under an inch at 50 yards, so to me, reducing the power in one is really counterproductive and taking away from the potential the gun was designed to provide in the first place. Just get a gun already at the power level you want, and choose a model with  a rep for accuracy. The 48's and 52's for instance are perfect candidates. Powerful, low hold sensitivity, and very very accurate.
does that rws 350 shoot 1/2 inch at 50 yds? that is PCP accuracy. plus detuning a magnum rifle you end up with a heavy 12 fpe rifle when there are many very accurate springers stock that are lighter and  at 12-15 fpe. it is like turning 4 wheel drive truck into 2 wheel drive

It's all pizza..what one likes another wouldn't touch and so on.... to each his own.   
I can tell you this.....that having had four shoulder surgeries , a de-tuned 48 is an all day shooter vs 30 min and put it away.
Had it out last week and shot it for three hours...Dime size groups at 25 yards....in fact , I can shoot staples off the target......so de-tuning has benefits you may not have considered.
As for de-tunig an RWS 350--- I would run away from that one ....get a 34. you can put an OS kit in it later.

Happy Shootin to All !
Petey
Title: Re: detuning magnum springers to medium power ???
Post by: angrytimes on August 26, 2014, 04:53:25 PM
Don't avoid an under/side lever because of some pics you have seen. If you look after your gun and treat it with respect it is not goin to cut your fingers off. I reckon get a Diana 48/52. Accurate, lethal, quiet, back yard friendly (with a solid pellet stop) and best of all you will not even need to molest it and cut up it's spring because all of this gun possesses all of these great qualities from the factory! Match it with a heavy duty hawke sport hd and a bkl one piece mount and you will have a very solid and affordable package. The t-06 trigger is awesome and it's German made.
Title: Re: detuning magnum springers to medium power ???
Post by: Petey on August 26, 2014, 05:56:07 PM


A 48 is not backyard friendly unless your yard is huge.... That short stroke ,large diameter bore pushes a lot of air....not exactly quiet. Again---de- tuned = far more quiet and with the right accessories it's even more quiet.
Either way a 48 is a great way to go.

 *** These Shrouds are no longer available= can't help ya ***
(http://i1193.photobucket.com/albums/aa347/NPetey/48/IMG_0634_zps020d858e.jpg) (http://s1193.photobucket.com/user/NPetey/media/48/IMG_0634_zps020d858e.jpg.html)

Title: Re: detuning magnum springers to medium power ???
Post by: angrytimes on August 27, 2014, 05:55:11 AM
What's not back yard friendly about it? My mate shoots his 52 near everyday and his neighbours have never had a problem with it. It's a.22 so not super sonic so yeah it's quiet. If you don't have shoulder problems why would you detune it? They are hunting guns and you decrease their ability to kill. Just why? If you want a 12fpe just buy a 12fpe.
Title: Re: detuning magnum springers to medium power ???
Post by: D14Jeff on August 27, 2014, 08:13:47 AM
conservation of momentum. decrease the velocity or increase the mass and it will kick less.

that's why ;)
and i like to tinker :)

i got so wrapped in the beautiful stock on the 135 that i forgot i wanted something with a built in suppressor ...... sometimes i'm a dumb butt , LOL
are the hatsan 85 and 125 snipers very front heavy like the crosman/benjamins with their metal shroud ?
they aren't wood , but ATM detuning a metal spring 125 sniper ......
http://www.airgunproshop.com/hatsan-airguns/viewcategory.php?groupid=9 (http://www.airgunproshop.com/hatsan-airguns/viewcategory.php?groupid=9)
.... or a full power vorteked 85 sniper is looking more interesting .
http://www.airgunproshop.com/hatsan-airguns/viewcategory.php?groupid=20 (http://www.airgunproshop.com/hatsan-airguns/viewcategory.php?groupid=20)

the 85 more so cause i can get a refurbed 95 later and swap the stocks and resell the 95 in the sniper stock for about the same cost as the 95 . FWIU the 135 stock wont work on the 125's :( . but the vortek piston/ram gets a lot of good comments .
 my AP is in full force !! LMBO .
Title: Re: detuning magnum springers to medium power ???
Post by: D14Jeff on August 27, 2014, 08:18:46 AM
HMMMMMMMMMMMM ......................

is a 125 or 85 sniper barrel a perfect fit on a 135 ?
if they will .... are they available anywhere in America ?
Title: Re: detuning magnum springers to medium power ???
Post by: Dick Tracey on August 27, 2014, 08:49:09 PM
The 135 has a larger dia piston, therefore, I don't it is a direct swap.
That should make the receiver a larger dia.


DT
Title: Re: detuning magnum springers to medium power ???
Post by: D14Jeff on August 28, 2014, 02:21:54 AM
well then i guess i'll get the 85 sniper when i'm ready and later on get a 95 and do the stock swap and sell .
Title: Re: detuning magnum springers to medium power ???
Post by: Benwaller on August 28, 2014, 10:33:12 AM
conservation of momentum. decrease the velocity or increase the mass and it will kick less.

Airguns are all about physics.  Good answer.

As I recall Momentum = Velocity X Mass; and Energy = Velocity squared X 1/2 Mass but I've been known to be wrong. 

In any case increasing Mass can bang a spring pretty hard, but they are pretty cheap to replace.  And this "double hammer" which can develop under a heavy pellet, does not contribute to accuracy - been there, done that. 

Being somewhat a shade tree mechanic and since cheap springers are reliably cheap platforms upon which to test ideas, I have considered changing the porting in a modified 'Hawk I have, enlarging it slightly, so to relieve some of that double hammer that develops with a heavy pellet.  I figure if there is more air getting to the pellet sooner the dwell time will be reduced, the pellet will start moving earlier and more momentum will be going to the pellet and not back into the piston.  I don't actually know any of this for sure but it sure seems reasonable enough.

Seems to me that the trick will be to not over enlarge the port which would likely establish a rough shot cycle and ruin the gun entirely.

One of these days I'm gonna' do it.  There will always be another gun.

 ;) Ben
Title: Re: detuning magnum springers to medium power ???
Post by: D14Jeff on August 28, 2014, 11:03:39 AM
be careful enlarging the port . this guy seems to know what he's doing and needed to make a port smaller because ..... " There's a very slight metal "ping" at the end of the shot cycle which I attribute to the front of the piston kissing the face of the compression tube.

This is becoming a semi-trend lately and if you're a regular reader (thank you), you can probably already guess as to the cause(s).  The transfer port on the gun is pretty large.  The bore is also on the loose side.  I can fix the transfer port, so that's up next. ...... "

at the bottom of that article .... http://anotherairgunblog.blogspot.com/2014/03/webley-hatsan-patriot-piston-buttoning.html (http://anotherairgunblog.blogspot.com/2014/03/webley-hatsan-patriot-piston-buttoning.html)

heres the article where he made it smaller .... http://anotherairgunblog.blogspot.com/search/label/webley (http://anotherairgunblog.blogspot.com/search/label/webley)

Title: Re: detuning magnum springers to medium power ???
Post by: Benwaller on August 28, 2014, 09:49:06 PM
I think this guy knows a lot about the subject no doubt about it, but his issue is a piston that is hurtling so fast and hard into the end of the compression cylinder that a metal-to-metal sound is being generated.  The characteristic that I am addressing is a bounce that occurs before the end of the stroke, which I think is being generated by the piston being flung back (however short lived that event is) by the slug of highly compressed air in the cylinder that is only there at that magnitude because the pellet is too heavy or the port is too small. 

Hmmmm.  Maybe all that has to happen is to clean up, fair in, the edges of that port.  I'll definitely do that first.

But if fairing the port proves insufficient I will bore out the port a little bit at a time, and re-fair, until that bounce is gone...or the cylinder port is so whacked that I'll have to order a new cylinder altogether and put the gun back together the way it is now, which is a really well-tuned rifle happy with 8 grain pellets.  Which is not the goal.  What I want here is a well-tuned rifle happy with Heavies.  I am not reluctant to test my ideas in pursuit of this goal.

Besides, failure does reliably encourage better work.  And I'm all about making progress.

 ;) Ben
Title: Re: detuning magnum springers to medium power ???
Post by: mafatone on August 28, 2014, 10:23:06 PM
I don't understand why people buy a magnum springer (like a HT-135, etc.) and then want to detune it. What was the point of buying it? You would have been better off buying a RWS 54 or similar which is known for their high quality and accuracy. Tar, clear tar, Moly, clear Moly, cutting coils from springs. Why would you even consider buying a magnum springer if you're going to this to it? I don't understand.......
Title: Re: detuning magnum springers to medium power ???
Post by: ptpalpha on August 29, 2014, 12:36:12 AM
Well, cutting coils is a seperate issue, but tar and moly have been the standard for lube-tuning for decades.  I highly doubt there's one springer on the line at any high-profile FT or benchrest competitions that don't have Maccari tar on the spring and Maccari moly for the lube.
As for why you would want to cut a coil off the spring, there are many reasons.  First, you fell in love with that particular rifle and hate the harsh shot cycle.  Or, you like everything about a rifle but want to find out of knocking 50fps or so off her will improve accuracy.  Maybe, like a lot of us, you just can't help yourself when it comes to tinkering and experimenting with airguns.
Finally, like the OP states in his opening post, the idea would be to chop the spring to make the rifle more docile, learn the ins and outs of how to shoot a springer, then replace the chopped spring later once you get your skill level higher.
Let's face it, springers can be difficult to shoot accurately and consistantly, and magnum springers add many difficult to navigate variables to that equation. 
Title: Re: detuning magnum springers to medium power ???
Post by: D14Jeff on August 29, 2014, 04:27:55 AM
Pappywith4 put a o=ring in his 125 and it looks promising . a %10 - %15 Fps reduction , less recoil and a noticeable increase in accuracy :)

http://www.gatewaytoairguns.org/GTA/index.php?topic=69933.msg676144;topicseen#msg676144 (http://www.gatewaytoairguns.org/GTA/index.php?topic=69933.msg676144;topicseen#msg676144)

http://www.gatewaytoairguns.org/GTA/index.php?topic=69933.msg676234;topicseen#msg676234 (http://www.gatewaytoairguns.org/GTA/index.php?topic=69933.msg676234;topicseen#msg676234)

http://www.gatewaytoairguns.org/GTA/index.php?topic=72651.msg692239;topicseen#msg692239 (http://www.gatewaytoairguns.org/GTA/index.php?topic=72651.msg692239;topicseen#msg692239)

http://www.gatewaytoairguns.org/GTA/index.php?topic=72379.msg693678;topicseen#msg693678 (http://www.gatewaytoairguns.org/GTA/index.php?topic=72379.msg693678;topicseen#msg693678)

i'm looking forward to his next teardown to see how it does over time .
Title: Re: detuning magnum springers to medium power ???
Post by: Paul68 on August 29, 2014, 10:54:55 AM
I think it comes down to basics, making the proper decision when buying a springer.

We always see a lot of threads where newbies want advice on buying a springer, but less commonly do we see either someone suggest the poster first decide what their needs and experience level are, or suggest a rifle that fits their needs/experience. This is the biggest mistake made when buying an airgun, and the biggest reason for so much discouragement and poor opinion forming of particular brands/models, or even airguns in general.

If some new shooter decides they want a handgun for home defense, you will never see experienced shooters suggest they get a 44 mag  shooting weak target rounds to make it more manageable. Same premise here.

For most folks, an introductory rifle should be light, docile, reliable, and reasonably accurate even in inexperienced hands. It is the time put in behind the trigger of such a rifle that prepares them for the later step up to something more aggressive. The basics of shooting form and procedure are best learned with a rifle that is forgiving, and trying to improve with something outside the realm of the intended purpose simply introduces an unneeded handicap.

Can you reduce the violence of a big magnum through modification? Sure. However, it will never be anywhere near as easy and forgiving a shooter as one of it half sized siblings. A Hatsan 125 for instance has a piston and spring over twice the size and weight of a D34 and a much longer stroke. You will never reduce the recoil in the 125 enough to make it as easy to manage as the 34. Even with the heavier overall mass of the gun.

 For an example, look at the RWS48 Sidelever, and the RWS350 Mag. I doubt anyone would argue that the 350 is easier to shoot than the 48, and in fact the opposite is true. The 48 is WAYYYYY easier to shoot and has a well earned reputation for accuracy and low hold sensitivity. However, both guns have a nearly identical weight and similar power ratio though the 350 edges ahead with 2-3 more fpe. Why is this? Because the piston assembly in each rifle is much different. The 350 uses a heavy piston with a long stroke to produce its power, which is why it is so hold sensitive. A lot of moving mass, with a relatively long lock time, means more movement lasting a longer amount of time. The longer that rifle is moving in your hands, the harder it is to maintain your aim point consistently, and add in the heavier moving mass of the piston, and you end up with a beast of a rifle. The 48 on the other hand has a slightly shorter stroke and lighter piston. Less moving mass and faster lock times simply means less movement, and quicker pellet launch. 

And if you do somehow manage to slow the piston down enough to get recoil levels even close to similar, we have to remember that air rifles are a balancing act in physics. You have then introduced a slew of other issues, including greatly increased lock times and greatly reduced power which directly affects trajectory. Basically, you have turned the gun into a slow and lumbering catapult that can actually be more hold sensitive because of the longer time it takes for the piston to complete its stroke and get that pellet moving.

Personally, I don't see much point in reducing power in a big magnum enough to detune it to the level of a "medium" power springer. I feel it would be wiser to concentrate on making the magnum as smooth and efficient as possible with a good tune and using it as it was intended, as a cannon of a springer meant to produce max fpe. For accuracy and ease of shooting, I would simply save myself the headache and get something intended for that purpose. 
 
Title: Re: detuning magnum springers to medium power ???
Post by: D14Jeff on August 29, 2014, 07:52:06 PM
thanks paul68 . any idea how the hatsan 95/85 piston weight and stroke length compare to the 125 ? or how the 95/85 piston weight and stroke compares to the rws 350/xs28m or rws 48 ?
Title: Re: detuning magnum springers to medium power ???
Post by: Paul68 on August 29, 2014, 10:01:25 PM
Don't have all the direct specs for your comparisons. Here's what I do have.

The Hatsan 125 has a 120mm stroke with an 8" long piston and 29mm receiver.

The RWS350 has a 6.31" long piston and 115mm stroke and 28mm reciever.

The RWS34 has a 5.19" long piston and 80mm stroke with 28mm reciever.

The RWS48 has a 100mm stroke with 28mm reciever.

The Hatsan 95 has a 27mm receiver with 100mm stroke.

You can safely assume the longer pistons will be heavier even though we don't have the wall thickness.
Title: Re: detuning magnum springers to medium power ???
Post by: Airjason on August 30, 2014, 04:40:54 AM
I had JM send me a low power spring for my R1 in .177. I wanted to lower the power on the R1 so I could shoot it indoors with less cocking effort and less noise. After changing the spring, the R1 chrono'd at about 740 ft/sec and I was happy at that. No twang. That was two years ago. Funny thing is that the gun now chronos at 910ft/sec. Somehow the R1 just broke in itself to the higher velocity. Oh well, I'll just leave it at that.
Title: Re: detuning magnum springers to medium power ???
Post by: BobbyHumphrey on August 30, 2014, 10:37:58 AM
     I'm curious of weight comparisons also. I'd wager there isnt a piston much heavier out ther than a hatsan  125. Piston weight , swept volume , transfer port size and possible spring tension all charted. That would be interesting.
Title: Re: detuning magnum springers to medium power ???
Post by: Dick Tracey on August 30, 2014, 01:06:33 PM
The Hatsan 135 will top the 125,  not sure about the weight.  There used to be a chart on the Web/Forums that showed a lot of these statistics, but it don't remember where it was.

DT
Title: Re: detuning magnum springers to medium power ???
Post by: BobbyHumphrey on August 30, 2014, 02:20:52 PM
   I've  read that the 135 has a larger swept volume than the 125. But it uses the same spring. Seems like you could squeeze more power out of a 135.
Title: Re: detuning magnum springers to medium power ???
Post by: Paul68 on August 30, 2014, 04:22:51 PM
Yeah, the 125 and 135 share the same 120mm stroke, but the 135 has a 30mm tube and the 125 29mm.

Title: Re: detuning magnum springers to medium power ???
Post by: D14Jeff on August 30, 2014, 11:00:41 PM
well here's what i'm thinking .... since it's impossible to get a sniper barrel for the 135 the 125 sniper is next on my list . of all the plastic stocks i see on sub $300 AGs it's the baddest butt looking by far IMO . it also seems to be the most ergonomic with it's adjustable length and comb , and i like grippy rubber sections . the action still has the weaver/dovetail rail and of course the german steel etc. . the camo looks nice , if i can't have beautiful wood i at least want pretty plastic .

i'm thinking of tuning it down to about 700-750ish fps / 17-19 fpe , that should make a very mild shooter considering the weight of the gun FWIU . if i want more power later get a new spring cut for 800-850ish fpe and if i ever can or want to try full power get a full power spring . i'm not afraid to do some smoothing , cleaning , polishing and lubing . i like tinkering ;)

any ideas on how many loops to cut off the spring to get it down to 700ish in .22 with 14-15 grain pellets ? looking on forums they seem to have 3 to 4 inches of preload ......

Title: Re: detuning magnum springers to medium power ???
Post by: D14Jeff on August 31, 2014, 09:24:34 PM
ok ... lets try this ......
will a hatsan 135 detuned to closely equal the FPE of a hatsan 85 be easier to shoot ?
Title: Re: detuning magnum springers to medium power ???
Post by: Paul68 on September 01, 2014, 12:50:55 AM
Yeah it would. But it wouldn't be as easy to handle as an 85.
Title: Re: detuning magnum springers to medium power ???
Post by: triggerfest on September 01, 2014, 03:57:14 PM
And what would be the influence of the caliber according to you in this whole story ? They say that a larger caliber is more easy to handle in a magnum springer though...
Title: Re: detuning magnum springers to medium power ???
Post by: D14Jeff on September 01, 2014, 04:20:05 PM
in .177 most pellets will want to go supersonic limiting selection to only heavy to very heavy pellets and increasing pellet cost . .25 is expensive and there's no place nearby that sells them so they will have to be ordered and shipped . .22 is the winner to me .

i did a lot of late night web searching on this last night a detuned xs28m from MM with his basic tune is a much simpler option . i'll know everything will be done right , and it's much easier to find parts for it too since it's based on the rws 350 . it also has a wood stock . but i'll want a LDC for it ..... anyone know what the barrel diameter is on the xs28m ? and are the diameters the same for .177 , .22 and .25 ? it's much easier to find parts for it too
Title: Re: detuning magnum springers to medium power ???
Post by: D14Jeff on September 02, 2014, 09:11:04 AM
looks like it's 15mm , same diameter as the barrel on a AR2078 .

http://www.wolfairguns.com/product_info.php?cPath=25&products_id=37 (http://www.wolfairguns.com/product_info.php?cPath=25&products_id=37)
$46 shipped ..... seems very reasonable .

sorry for being so wishy washy .... LOL .