Synrod with Hill mods 24 shots ES 2.7% 833 fps avg

[jruther2]

First off, I feel the need to say that I mean no offense to anyone.
I tried using analogue gauges, a drill press, etc. - and for the hobbiest, that's probably ok. But since I also supply components to others, as well as myself, I feel a duty to keep the tightest tolerances and/or standards, possible. That's why I switched from testing with an analog gauge to a digital gauge for pressure readings, and to a mill, and lathe (CNC when possible), for making/modifying the components - which usually helps me to stay within +/- 0.001 from each part to the next.

Ok, with that being said…
I purchased the pictured digital gauge from McMaster-Carr in November of 2013, ***links removed***.
This gauge's accuracy is rated at +/- 1% and it measures pressure up to 5000psi. I have found this gauge to reliable, accurate, and have not had to change the battery since I started using it.


Tim

No offense taken here for sure.  Inaccuracy on pressure readings has been bugging me. Now I'm going to make it right.  I ordered the digital gauge. (Boy, this really is the dark side...people just toss out links straight to a part so I can order it with no remorse whatsoever!  ) As far as the machine work goes, I actually have access to a mill and lathe, just not at my house so sometimes I get in a hurry and use what I have on hand...then I take it to the shop and make it right lol.  I completely respect your attitude about high standards as you are providing parts for customers, not just yourself.  While I never had any complaints and always had very happy customers, I actually got out of making custom items because of the high standards I wanted to deliver. It ended up turning a hobby into too much work at home and not enough income from it to justify the stress.
Thanks for the quality of work and parts you provide HIll, I am a very satisfied customer!  Thanks for the info about the gauge as well.

[jruther2]

I have been doing more testing with all the “Hill mods” installed which include a modified valve, modified gauge block, modified transfer port, as well as the de-pinger.  I also had the 12.5# spring installed for these strings unless otherwise specified.
For the sake of accuracy, I purchased a digital gauge for my rifle just for testing purposes and I'm much more confident in my pressure reporting. I'll summarize the results of a few of my strings below. 
If anyone would like to see the entire strings I'll be glad to post them.

Pellet:  JSB Exact Kings 25.39gr

Settings: Spring and stroke at 0 VMS 5ccw
24 shots from
2828psi to
1895psi
Max 832fps
Min 815fps
Ave 825fps
ES 17fps/2.0%

Within the same string I got
16 shots from
2651psi to
1939psi
Max 832fps
Min 822fps
Ave 827fps
ES 10fps/1.2%

Settings: Spring 2cw stroke 6cw VMS 5ccw
24 shots from
2688psi to
1772psi
Max 829fps
Min 803fps
Ave 818fps
ES 26fps/3.1%

16 shots in the same string from
2564psi to
1932psi
Max 829fps
Min 816fps
Ave 822fps
ES 13fps/1.6%

Settings: Spring 0 Stroke 6cw VMS 5ccw
24 shots from
2388psi to
1576psi
Max 796fps
Min 774fps
Ave 779fps
ES 22fps/2.8%

16 shots in the same string from
2244psi to
1721psi
Max 796fps
Min 783fps
Ave 790fps
ES 13fps/1.6%

Finally, for those who are interested in a low pressure/low velocity string I put the stock hammer spring back in and set Spring and Stroke to 0 with VMS still at 5ccw and got the following:

32 shots from
2241psi to
1451psi
Max 730fps
Min710fps
Ave 722fps
ES 20fps/2.7%

24 shots in the same string from
2130psi
1481fps
Max 730fps
Min 718fps
Ave 724fps
ES 12fps/1.6%

I may shoot a few more strings with the stock spring and Hill mods and post them if anyone is interested.

[HillGSA]

Should cover almost everyone   

[jruther2]

Should cover almost everyone   

I'll be working on a higher power tune either later this evening or tomorrow.  Maybe only in the 10 shot range, we'll see...

[jruther2]

Its been a while since I updated and I have been doing lots of testing with the Hill mods.  Below are the results of my high power tuning and below that is my favorite tune so far. As always, questions, comments, and criticism welcome.

High power tune



40 shots @ 813 fps avg and 5.05% ES