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 Post subject: Amazing 1740
PostPosted: Tue Jan 07, 2014 12:30 pm 
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Location: Central West River Nova Scotia
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Here,s the gun. 2240 with 18" .177 barrel, hence 1740. HiPac conversion with 2 extensions. Here,s where it get,s AMAZING !!! While researching for a new gun, Daystate, mentioned that they didn't have to regulate their new huntsman regal because of the new "slingshot" hammer. I don't know how it work,s, but I "assumed" it work,s on the principle that a heavy hammer and spring with NO preload on the valve, will, when flung at the valve, open it the valve allowing just the right amount of air to push the pellet at a pre set speed according to the spring tension flinging the hammer. As pressure decreases, the valve stays open longer, maintaining pellet speed. :rolleyes:
Any way... Since I was putting the .177 barrel on my 2240 to go starling hunting with Wayne, I had to change the hammer spring anyway, to go sub 500 fps. So I decided to try "my" version of the "slingshot hammer". After 2 hours of trying different springs and cropping springs, I finally got down to 498 fps. So now I wanted to see how many "useable " shots I would get with the HiPac, with 2 extensions and filled to 2000 psi. Here is that string........498...498...505..00ps....510..oops again. Well I'm not disassembling the gun again. Maybe it'll drop back when the pressure drops. 568..oh oh..554...556...527..here we go...528...535..534...536...hmm..534...534...539...536...544...576..oh oh again .579...582...582...582...588...588...586...592...586...592...592...592...589...588...598...598...600.. oh sh**600...604...602...603...606...606...609...609...609... (SHOT 41...612)...616...614...619...619...617...618...619...622...588..sudden drop...622...627...627...627...626...589...626...628...624...627...592 sudden drop again..592...error...592...589...596...592...592...636 second wind 637...634...634...640...639...601 another drop 594...(640)... wtf.? .597...597...604...607...603...598...603...600...603...599...594...597...597...596...596...634 a third wind 634...633...635...633...635...(SHOT 101..631)Woa nellie....628...625...624...623...616...617...614...611...610...608...607...600...597...591...588...550...543...539...535...(SHOT121..533)...564 oops..523 ahhh..556 oops again..552...548...543...533...531...522...520...516...509...502...498...492...490...482...473...469.
Total 140 shots. By the last shot the POI was 1" below POA. And went as high a 3/4" above during the entire string. I believe the sudden drops and rises was the hammer spring catching on the RVA Which was broken a while back. I know the pellet speed was over legal, and I will fix that, but I couldn't believe the shot count at those speed,s. With such a small reservoir. When I get under 500 fps, I suspect I'll get even more. I need more pellets.

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Last edited by joe hickey on Tue Jan 07, 2014 1:52 pm, edited 1 time in total.

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 Post subject: Re: Amazing 1740
PostPosted: Tue Jan 07, 2014 12:37 pm 
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Location: Coalmont BC
The "slingshot" hammer, as I understand it, has two parts, one pushed by the spring and the other going along for the ride.... The sprung part stops and the other part keeps going (through it's own momentum) to open the valve.... When the valve slams shut, that part doesn't partially recock the spring, so no hammer bounce, and no air wasted.... Having said that, using a stiff, short spring that has free play instead of preload tends to do the same thing....

Bob

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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
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 Post subject: Re: Amazing 1740
PostPosted: Tue Jan 07, 2014 12:46 pm 
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That is indeed a very fine shot count!

Is there any chance you could post the dimensions of those hipacs? I'd be really interested to know the total volume of the air reservoir :)

I'm working on my first stock at the moment, and in doing so I'm filled with a whole new level of admiration for what you do Joe. That is really beautiful work.


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 Post subject: Re: Amazing 1740
PostPosted: Tue Jan 07, 2014 12:47 pm 
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Location: Central West River Nova Scotia
Just what I thought. Thank,s Bob.

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 Post subject: Re: Amazing 1740
PostPosted: Tue Jan 07, 2014 12:58 pm 
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Very nice Joe light compact not sure why your looking to spend more money :lol:

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 Post subject: Re: Amazing 1740
PostPosted: Tue Jan 07, 2014 1:32 pm 
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Location: Brant County
Beautiful stock ;) and thats all i got lol

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 Post subject: Re: Amazing 1740
PostPosted: Tue Jan 07, 2014 1:48 pm 
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Ace wrote:
Very nice Joe light compact not sure why your looking to spend more money :lol:

DUNNO :?

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 Post subject: Re: Amazing 1740
PostPosted: Tue Jan 07, 2014 2:09 pm 
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in case anyone,s interested. The pressure in the gun when I went to fill it was 600 psi. 140 shots avg 600 fps using 1400 psi.

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