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 Post subject: Re: Hammer Time
PostPosted: Tue Feb 27, 2018 11:46 am 
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Joined: Sat Nov 03, 2007 4:19 pm
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Location: Coalmont BC
Think about it this way.... you now have a vented hammer that can't trap air in front or create a suction behind on firing.... 8)

Bob

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 Post subject: Re: Hammer Time
PostPosted: Tue Feb 27, 2018 2:27 pm 
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Joined: Wed Oct 17, 2007 3:27 am
Posts: 2585
Location: Winnipeg, Canada
This is one of the reasons why I post here- I can get a bit wrapped up in and carried away by my own ideas, right or not. :shock:
At least you guys saved me an extra vent hole at the rear of the hammer :wink: :rolleyes:

I'd sure like to know what that stainless is. Tool grade absolutely, and I think ideal for what I'm applying it to. It sure cleaned up the cocking cycle. I've got a bit left for future hammer improvements.
I'll have bit more tonight off the chronograph....

-D.S.

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 Post subject: Re: Hammer Time
PostPosted: Thu Mar 01, 2018 4:57 am 
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Location: Winnipeg, Canada
Finally got it over the chronograph with the new hammer.

At the top end of 25 pumps with JSB 18.1 gr Heavy, the gun's a whisker slower than the brass/stainless, avg 568.3. That 8 fps or so could be temperature related as I started with an extremely cold gun. It could also be that the new stainless hammer is lighter in weight...
I don't think it's enough of a velocity loss to be overly concerned with.

I also ran some of the 14.3 gr Premier points through it. It breaks 500 right at ten pumps, and shades 621 fps at 25 pumps.

There's a telling tale in the numbers though.... Just about all across the test spectrum, the premier pointeds are 3 times the extreme deviation spread of the JSB's... This does not bode well for the premier's in my book. I think I'm going to quit buying them.

I am pleased with this latest hammer. I think it's the 5th one I've done, and is by far the smoothest cocking of the lot.
I can start into the next project confident that I have a decently performing hammer to put into it.

-D.S.

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 Post subject: Re: Hammer Time
PostPosted: Thu Mar 01, 2018 6:11 pm 
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Joined: Sat Apr 16, 2011 5:58 am
Posts: 495
Location: Eastern Ontario
Doc Sharptail wrote:
At the top end of 25 pumps with JSB 18.1 gr Heavy, the gun's a whisker slower than the brass/stainless, avg 568.3.


If you were shooting a PCP, I would say that since brass is heavier than steel, then the slight weight advantage of the brass/stainless hammer could possibly be giving you a smidgen more poppet dwell time, accounting for the slight fps gain, but we're talking pumpers here so forget that theory...

If only 8fps difference & no retained air with either hammer, then pffft....may as well call them twins! :lol:

Too many variables involved for such a tiny difference in fps, it's like you said...not even worth thinking about.

Nice job! 8)

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 Post subject: Re: Hammer Time
PostPosted: Thu Mar 01, 2018 6:48 pm 
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sholo wrote:
Doc Sharptail wrote:
Too many variables involved for such a tiny difference in fps, it's like you said...not even worth thinking about.

totally agree 8fps is nothing...you can shoot a pea through a straw faster then that lol.... :wink:

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 Post subject: Re: Hammer Time
PostPosted: Thu Mar 01, 2018 7:17 pm 
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Location: Eastern Ontario
Ace wrote:
you can shoot a pea through a straw faster then that lol.... :wink:

:lol: :lol: :lol:

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 Post subject: Re: Hammer Time
PostPosted: Thu Mar 01, 2018 10:23 pm 
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Joined: Sat Nov 05, 2016 10:52 am
Posts: 2924
Location: Caronport, Saskatchewan
Lol! [emoji38]

Sent from my LG-H812 using Tapatalk

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 Post subject: Re: Hammer Time
PostPosted: Thu Mar 15, 2018 3:35 am 
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Joined: Wed Oct 17, 2007 3:27 am
Posts: 2585
Location: Winnipeg, Canada
I ran this gun's evil twin over the chrony last night~ it will be the donor for most of the 2200/13XX conversion. It wears a 24" 22-60 bbl, and has a custom brass FTP in it. It has the new version 13XX valve in it with no bleed vent.

For a 6" increase in bbl length, the results are certainly gratifying.

At ten pumps with the 18.1 gr .22 cal. JSB Heavy, it averages 500.0 right on the nose. Extreme spread is 12.6 fps over ten shots.

According to my latest notes, and averages, that is an increase of almost 27 fps. Sweet spot for this bbl and power plant and pellet appears to be 15 pumps with and extreme spread of just 3.2 fps over 10 shots. To top that all off, the t.p. seal is leaking a bit.
I'm going to have to order some parts in, especially the t.p. seals.

I'm itching to get this conversion off the ground...
Will have to make a parts list, and get an order rolling.

-D.S.

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 Post subject: Re: Hammer Time
PostPosted: Thu Mar 15, 2018 12:06 pm 
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Location: Caronport, Saskatchewan
Great results!

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