Liberty Reg not working

[Madd Hatter]

Well, I just finished making a hammer weight out of either a 3/8 carbide drill bit or a 3/8 HSS drill bit. With the weight of the short jobber drill bit I'm thinking carbide. Hack saw wouldn't even scratch it. I got the length is with only one washer it will end up being the same stack height as the original spring. With the HS adj I'm getting from Duy I should be able to tune my bad boy Liberty right in. The weight came in at 82.5 grains which I believe is the same weight Duy is using. I chucked the drill bit in my drill press up side down and used a dremel cut off wheel. Well actually, about 5 or 6 cut off wheels. That thing was hard, it wore those disks right down.

[darkcharisma]

a stainless bolt from hardware store would have been easier?

[Madd Hatter]

And your point is??? lol I also could've used the spend 9mm bullet I've got sitting here and it would be 110 gr. Hum,  I may just do that! The cylindrical part of the slug is almost the same length as the weight I made which would be and the pointed part of the slug would fit inside of the HS.

[darkcharisma]

LOL my point is exactly what you are doing with the 9mm bullet. utilization of the shortest route to your goal? and i k ow you dont like the 100 degree heat. was it lower this time when you grind that hammer weight? lol

[Madd Hatter]

It was in the high 80's to very low 90's. My wife found it when she was out with my son and grand daughter. I found that with that in the hammer the over all length is exactly the same as with the stock spring and no weight.

[Madd Hatter]

Well, I thought the stack height was the same as stock but had to take a .100 off of the slug. Ended up with 505 grains total hammer weight without the spring.

[Madd Hatter]

I did a check of what the regulator is doing now after increasing the vent hole size and polishing the reg bore. First shot after sitting all night at 3200 psi with jsb 18 g was 957. Second shot was 946. Don't think a 11 fps change is very much at all. Still need to do a shot string to see what the rest of a string looks like.

[Madd Hatter]

Here's a 10 shot string I did. It ended up being a 14 fps spread.

[Madd Hatter]

Just did some slug testing with my Liberty using Stephen's 26 gr slugs and some 26 gr Griffin slugs. Reg turned up 1/4 turn CCW hammer spring adj adj as high as it would go before coil bind.

Created   Description   Notes1   Notes2   Distance   Coeff   Weight   Temp   BP   Altitude
11/23/2019 17:40   26 grain AVS slugs   4000   3600   1   1   26.1   N/A   N/A   3000
#   FPS   FT-LBS   PF                  
5   947   51.98   24.72                  
4   950   52.31   24.8                  
3   953   52.64   24.87                  
2   954   52.75   24.9                  
1   959   53.31   25.03                  
AVG   StdDev   Min   Max   Spread   TrueMV   Shots/Sec   Group Size      
952.6   4.51   947   959   12   952.71   0.08   0      


Created   Description   Notes1   Notes2   Distance   Coeff   Weight   Temp   BP   Altitude
11/23/2019 17:34   26 grain Griffin slugs   3800   3150   1   1   26   54 °F   1019.91 inHG   3000
#   FPS   FT-LBS   PF                  
5   925   49.41   24.05                  
4   930   49.94   24.18                  
3   930   49.94   24.18                  
2   940   51.02   24.44                  
1   938   50.8   24.39                  
AVG   StdDev   Min   Max   Spread   TrueMV   Shots/Sec   Group Size      
932.6   6.23   925   940   15   932.71   0.07   0      

I don't think the reg is doing anything.

[RDB]

Why do you think that?

[Madd Hatter]

Vel. keeps dropping.

[RDB]

Start pressure? I understand not wasting slugs. But 10 shots would tell more of a story. It may have leveled off. If start pressure was 3500psi or so... I dont think you could have cracked the valve hard enough to get those speeds with slugs

[BackStop]

Just did some slug testing with my Liberty using Stephen's 26 gr slugs and some 26 gr Griffin slugs. Reg turned up 1/4 turn CCW hammer spring adj adj as high as it would go before coil bind.

Created   Description   Notes1   Notes2   Distance   Coeff   Weight   Temp   BP   Altitude
11/23/2019 17:40   26 grain AVS slugs   4000   3600   1   1   26.1   N/A   N/A   3000
#   FPS   FT-LBS   PF                 
5   947   51.98   24.72                 
4   950   52.31   24.8                 
3   953   52.64   24.87                 
2   954   52.75   24.9                 
1   959   53.31   25.03                 
AVG   StdDev   Min   Max   Spread   TrueMV   Shots/Sec   Group Size     
952.6   4.51   947   959   12   952.71   0.08   0     


Created   Description   Notes1   Notes2   Distance   Coeff   Weight   Temp   BP   Altitude
11/23/2019 17:34   26 grain Griffin slugs   3800   3150   1   1   26   54 °F   1019.91 inHG   3000
#   FPS   FT-LBS   PF                 
5   925   49.41   24.05                 
4   930   49.94   24.18                 
3   930   49.94   24.18                 
2   940   51.02   24.44                 
1   938   50.8   24.39                 
AVG   StdDev   Min   Max   Spread   TrueMV   Shots/Sec   Group Size     
932.6   6.23   925   940   15   932.71   0.07   0     

I don't think the reg is doing anything.

The % of variation is minuscule in both cases.   Based on the StdDev/AVG

0.0047344110854503 for the top shot string

and

0.0066802487668883 for the bottom.

Both right around 1/2 of 1 percent variation!   Looks pretty good to me!

Of course, I was never really good at math...

If based on the spread divided by the min/max velocity, you still come out looking REALLY good!

For the top it is from 0.0125130344108446 to 0.0126715945089757 or between 1.25% and 1.27% variation.

For the bottom it is from 0.0159574468085106 to 0.0162162162162162 or between 1.60% and  1.62% variation.

Again... looks REALLY good to me.

Shoot a really long string and see how those percentages hold up.

[BackStop]

Start pressure? I understand not wasting slugs. But 10 shots would tell more of a story. It may have leveled off. If start pressure was 3500psi or so... I dont think you could have cracked the valve hard enough to get those speeds with slugs

I used to think that my .177 Freedom's sweet spot started at 3000 to 3100.   I retested recently and found it to be closer to 2800/2700.   Above that, the fps was closer to 700fps on low power and from 2800/2700 down to about ~2200/2100 it was pretty consistent at ~730fps.

Still, that is over 4% variation.   I like to have it as much under under 5% as I can manage!

[Madd Hatter]

I started at 4000 psi and ended at 3600 psi with the avs slugs which is 1.6 efficiency. That part I like. I used the stock but ported by me valve with Duy's Delrin poppet.

[RDB]

Its working then. Just not optimal. No way you could have cracked the valve at 4000 if the reg wasn't working.

[Madd Hatter]

I have a HS adj and it is adj to the max before coil bind. I'm going to do a shot string using JSB 18.13 gr pellets because I have 2000 of them just to see.

Created   Description   Notes1   Notes2   Distance   Coeff   Weight   Temp   BP   Altitude
11/24/2019 11:10   18 jsb shoot down to 2000 psi   start 3600 psi   end 2500. 1/4 turn ccw hs adj maxed   1   1   18.13   56 °F   1020.91 inHG   3000
#   FPS   FT-LBS   PF                  
20   957   36.88   17.35                  
19   968   37.73   17.55                  
18   972   38.04   17.62                  
17   978   38.51   17.73                  
16   985   39.06   17.86                  
15   996   39.94   18.06                  
14   997   40.02   18.08                  
13   1001   40.34   18.15                  
12   1013   41.32   18.37                  
11   1014   41.4   18.38                  
10   1016   41.56   18.42                  
9   1025   42.3   18.58                  
8   1030   42.72   18.67                  
7   1035   43.13   18.76                  
6   1044   43.88   18.93                  
5   1050   44.39   19.04                  
4   1052   44.56   19.07                  
3   1056   44.9   19.15                  
2   1067   45.84   19.34                  
1   1065   45.67   19.31                  
AVG   StdDev   Min   Max   Spread   TrueMV   Shots/Sec   Group Size      
1016.05   33.72   957   1067   110   1016.17   0.08   0      


Turned reg down to 1/8 turn ccw started at 4000psi using griffin slugs

Created   Description   Notes1   Notes2   Distance   Coeff   Weight   Temp   BP   Altitude
11/24/2019 11:25   26 griffin slugs   start 4000 psi   3550 psi end   1   1   26   57 °F   1020.91 inHG   3000
#   FPS   FT-LBS   PF                  
9   818   38.64   21.27                  
8   817   38.54   21.24                  
7   817   38.54   21.24                  
6   817   38.54   21.24                  
5   819   38.73   21.29                  
4   820   38.83   21.32                  
3   820   38.83   21.32                  
2   821   38.92   21.35                  
1   835   40.26   21.71                  
AVG   StdDev   Min   Max   Spread   TrueMV   Shots/Sec   Group Size      
820.44   5.66   817   835   18   820.54   0.08   0      

[darkcharisma]

ya need a gauge installed in the plenum to tell what the reg is doing

[Madd Hatter]

I know I do but haven't heard anything about the new plenums being available. That's what I'm waiting for.

[Madd Hatter]

Did a little shooting with the Liberty. 40 yards off of a bipod prone on the garage floor. Obviously it's not zeroed but couldn't shoot any longer as my neck hurt real bad. This was a 10 shot string with maybe 2 mph wind gusts from the east. I was shooting at the center target.