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PostPosted: Mon Oct 29, 2018 8:24 pm 
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Joined: Sun Oct 27, 2013 2:03 am
Posts: 26
i have a question, if i want to simply increase my power on my spring powerd hatsan mod 40 , what is the best way i have heard of people stretching the spring , but ive also heard people say they compress it by adding a few coins in the back of the spring and that also increases power . what is more effective , i can say i noticed a slight increase in sound and power when i stretched my spring


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PostPosted: Mon Oct 29, 2018 8:40 pm 
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Joined: Mon Mar 27, 2017 7:06 pm
Posts: 840
Location: Meaford, Ont.
I have found stretching springs they revert back to where they were in a short period of time. I add a little piece of pvc (Electrical Conduit). Makes the gun quieter also with just a solid thud when shot. CHEERS!


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PostPosted: Mon Oct 29, 2018 9:54 pm 
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Joined: Sat Nov 03, 2007 4:19 pm
Posts: 8973
Location: Coalmont BC
When you stretch a spring to a longer length, or "set" it to a shorter length.... you don't change the spring rate, but you do change the preload.... more preload by stretching it, less by setting it.... Providing the stretched spring is not compressed to reduce its new longer length, you will get more "power".... However, if you stretch a spring and then when it compresses on cocking that compression force exceeds the yield strength of the (now longer) spring, it will revert to the length it had before you stretched it, or something in between....

Increasing the preload by inserting a spacer will also increase the power, unless when you cock the gun the increased stress exceeds the yield strength, in which case the spring LOA will decrease, and if you disassemble the gun and measure the spring, it will be shorter.... Basically, any given spring will have a maximum force it can develop which occurs when the spring is "coil bound", ie all the wire coils are touching and the spring cannot be compressed any further....

Some spring gun tuners, when installing a new spring "set" it completely by compressing it over a guide (to keep it straight) until the coils touch.... This is the maximum force it can ever achieve.... If installed with a spacer so that when cocked the spring is JUST fractionally longer than its coil bound length, that is maximum power with that spring.... Whether the gun shoots as smoothly at that setting is entirely another matter, of course.... Setting the spring in this manner has one additional benefit, the spring is unlikely to get shorter with use, because it has already been fully compressed during the setting process.... Any subsequent compression should not cause it to yield and get shorter.... Using preload to adjust the cocked length will then provide more consistent results over the life of the spring....This is particularly true if you use a shorter spacer and run the spring with significantly less load than maximum....

Bob

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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal;
Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!


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PostPosted: Tue Oct 30, 2018 2:12 pm 
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Joined: Wed Jan 05, 2011 12:35 pm
Posts: 5998
Location: P.G. B.C.
If you want more power, buy a more powerful rifle.

I 'see' you are going to make your rifle diesel to increase power - you might make that come true, until the gun breaks - either seal, spring or likely both.

If you have a P.A.L. - buy the more powerful gun. If you do not have a P.A.L. - you are breaking the law if you put it much over 500fps with normal pellets.

If a .22 cal, anything over 500fps is illegal. Sub 500fps, imho are not ethical hunting guns.

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PostPosted: Fri Nov 02, 2018 1:49 am 
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Joined: Sun Oct 27, 2013 2:03 am
Posts: 26
yah i have a good knowledge of local law and hunting regulation , if only these damn guns could kill something , went out this weekend and gave 2 birds a good wack in there noggin and they both got away probably be sore for the next while or dead in a few days, the 500fps rule is kind of flawed in my opinion for this reason


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PostPosted: Fri Nov 02, 2018 2:59 am 
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Joined: Sun Oct 27, 2013 2:03 am
Posts: 26
check this out http://airguns.ro/Hatsan-Air-Rifle/Hatsan-MOD-40-89.html

my gun says 495 FPS on the side but here it says 650


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PostPosted: Fri Nov 02, 2018 5:48 am 
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Joined: Mon Feb 06, 2017 8:13 am
Posts: 156
I would assume it's a detuned model for the Canadian market, to make sure you don't wack too many birds in there noggin.


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PostPosted: Fri Nov 02, 2018 7:43 am 
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Joined: Mon Aug 08, 2016 7:23 am
Posts: 2776
Location: Somewheres near the Atlantic
jblaze wrote:
check this out http://airguns.ro/Hatsan-Air-Rifle/Hatsan-MOD-40-89.html

my gun says 495 FPS on the side but here it says 650


Because your gun was detuned for the Canadian market. Airguns are firearms over 500 FPS, and thus require a firearm license. Some do not want that. And there a market for detuned guns.


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PostPosted: Fri Nov 02, 2018 12:42 pm 
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Joined: Thu May 04, 2017 6:41 pm
Posts: 136
Location: Vancouver BC
I added a spacer to my C-Tire Hatsan Mod55S spring.
PICTURES - #p528453


I cut down CO2 bulbs to make spacers. The tapered nose of the co2 bulb secures it in the spring.
I tried putting spacers at the end of the spring but it would no longer cock, even with a thin washer.
Putting the spacer at the piston allows it to be cocked and did boost the power.

Of the three spacers I made out of CO2 bulbs the big one was the only one that made a difference.
I think I could get a full co2 bulb in there but stopped because the plastic plunger on the piston is also a 'Canadian Version' made to reduce velocity so spring shimming will only get you so far. For me it was enough.

My Hatsan now 'feels' more like a 'springer' with all the difficulties of shooting a full power one.
Although practicing with it has made me a better PCP shooter. It made me realize I was putting too much pressure on the stock comb with my cheek sending pellets to the left.


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PostPosted: Fri Nov 02, 2018 3:15 pm 
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Joined: Sun Oct 27, 2013 2:03 am
Posts: 26
wow wish i would have seen this before i modified mine ..

i want to post pictures but putting the spring in mine i almost dislocated my arm and i tore my palms up

i basicly took this door spring Image

through it down into the plunger/ piston and put a small steel washer then put the existing spring on the gide rod and crammed it all in , it sounds VERY dangerous now


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PostPosted: Fri Nov 02, 2018 3:32 pm 
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Joined: Thu Oct 04, 2012 10:27 am
Posts: 1108
Location: Thunder Bay,On.
MY GOD!!!!! :shock:

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PostPosted: Fri Nov 02, 2018 6:06 pm 
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Joined: Sun Oct 27, 2013 2:03 am
Posts: 26
thunder bay eh? were are you hunting lately spruce river road lol


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