Hatsan at44 silicon hose mod follow up

[Mont]

It's been quite a while since I have seen any thing on the at44 silicon hose Mod.  I was wondering if there where any long term news.  I thinking about doing this to a at44 to help quite down the hammer smack.
Here's one of the old string I found on the mod,
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https://www.gatewaytoairguns.org/GTA/index.php?topic=119251.msg1151365#msg1151365
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Any up date or pictures of the mod would be great. 
Thanks Just Joe

[redlined_b16a]

If I find time I'll get it apart for pics.

[redlined_b16a]

The silicone fuel tubing is 1/8"i.d. nitro fuel tube.It sits between the brass sleeve that the airtube screws into and the hammer.
Leave the hammer stop screw out.
The hammer hits the valve pin and bounces off of the silicone tube.
With chronograph data before and after you should notice a slight increase in efficiency.

You waste a lil less air.
It's possible to install silicone tubing without complete dissassembly.
If you are good you can remove air tube and stock.
Remove hammer stop screw.
Cock gun to pull hammer back.
Work the silicone tube in place thru the air tube hole with o ring picks.

[Mont]

Thanks for the up date,  I actually took my At44 apart this week end and started dong some experimenting of my own.  My goal was to quite down the Hammer smack while improving the shoot count.  I found that there was .210 from the from the hammer to the stop screw.  So I placed a piece of  .220 OD rubber hose.  It definitely helped with the noise.  I haven't done enuff testing to be sure the shoot count improved.   

One question I did have,  did you leave the hammer stop screw in?

[tejon]

My setup is similar, i have a .200 square oring piece in mine. No hammer screw anymore.

It definitely helped with efficiency but at lower pressures. I think too much throw. Matter of fact i just slid a .028 shim in there to see what happens. Hopefully a better curve from higher pressure. But No time to chrono this week...

[redlined_b16a]

I left the stop screw out.No longer needed and tge fuel tube(silicone)will improve shot count.It did for me.

Thanks for the up date,  I actually took my At44 apart this week end and started dong some experimenting of my own.  My goal was to quite down the Hammer smack while improving the shoot count.  I found that there was .210 from the from the hammer to the stop screw.  So I placed a piece of  .220 OD rubber hose.  It definitely helped with the noise.  I haven't done enuff testing to be sure the shoot count improved.   

One question I did have,  did you leave the hammer stop screw in?

[drummerboy7816]

Good timing on this post as I'm starting to look into this as well.  Any shot string data to support efficiency would be great!   I plan to do this soon and will share my findings. 

Efficiency wise, I'm already pretty happy as is stock with no buffer mod as I'm getting 27 shots (3 clips) @ 45 FPE average, 3.7% ES, 0.90 ci/FPE (string below).  I'm doing it primarily to bring down the noise, but if I can also bring up the velocity of the last few shots of the string that would bump me to around 2% ES!

#   FPS   FPE           Bars
1   882    43.87    200
2   886    44.27    
3   886    44.27    
4   891    44.77    
5   886    44.27    
6   892    44.87    
7   896    45.27    
8   896    45.27    
9   896    45.27    170
10   896    45.27    
11   896    45.27    
12   901    45.78    
13   901    45.78    
14   901    45.78    
15   901    45.78    150
16   896    45.27    
17   896    45.27    
18   891    44.77    
19   896    45.27    
20   901    45.78    
21   891    44.77    
22   886    44.27    
23   882    43.87    130
24   882    43.87    
25   877    43.37    
26   870    42.68    
27   868    42.49    120

[tejon]

Awesome string.... is it a .25 cal?

[redlined_b16a]

Somewhere in an old at44 .22 cal thread I done before and after shot strings.
Only thing it changed for me was a lil lower fps at same preload.Just put more preload to get the fps back and my shot count increased a bit due to wasting less air.

[drummerboy7816]

Awesome string.... is it a .25 cal?

Yep, that's .25 with JSB kings.  Oh and also it's a bullboss not AT44.

[redlined_b16a]

Good timing on this post as I'm starting to look into this as well.  Any shot string data to support efficiency would be great!   I plan to do this soon and will share my findings. 

Efficiency wise, I'm already pretty happy as is stock with no buffer mod as I'm getting 27 shots (3 clips) @ 45 FPE average, 3.7% ES, 0.90 ci/FPE (string below).  I'm doing it primarily to bring down the noise, but if I can also bring up the velocity of the last few shots of the string that would bump me to around 2% ES!

#   FPS   FPE           Bars
1   882    43.87    200
2   886    44.27    
3   886    44.27    
4   891    44.77    
5   886    44.27    
6   892    44.87    
7   896    45.27    
8   896    45.27    
9   896    45.27    170
10   896    45.27    
11   896    45.27    
12   901    45.78    
13   901    45.78    
14   901    45.78    
15   901    45.78    150
16   896    45.27    
17   896    45.27    
18   891    44.77    
19   896    45.27    
20   901    45.78    
21   891    44.77    
22   886    44.27    
23   882    43.87    130
24   882    43.87    
25   877    43.37    
26   870    42.68    
27   868    42.49    120

My string was very similar cept it was pushong a lil more fps out the box.

[tejon]

Awesome string.... is it a .25 cal?

Yep, that's .25 with JSB kings.  Oh and also it's a bullboss not AT44.

Still... great string... makes me want a bullboss .25 even more....

Im trying to get more fpe from mine for long range shooting without wasti g air.. i think i've read your post a few times redlined... good info there.

Any update just joe?