DAR... We Have A Problem...

[Firewalker]

I turned the reg back to factory settings, spun the hammer spring cap all the way out and with the bolt uncocked, turned the cap in until it contacted the spring for a starting point. I got 2 more shots and 1 more turn of the cap this way. Starting pressure was 21MPa and end pressure was 18MPa. 9 shots taken, trigger failed to catch sear on shot #10. The results are below.

My initial impression is to do 1/4 turns and see if there is more useable data.

1-630
2-662
3-719
4-754
5-786
6-860
7-908
8-931
9-941

[RDB]

There we go! A quarter turn on the reg is a 30 bar swing....if not more. 2 turns would most likely  make it inoperable. 

Dinner time....will try and help some later.

[RDB]

Ok....forget about the word "KNEE" and think plateau.

From your shot string...you were getting very close to your velocity plateau.  Or top of your knee. If you had a little more hammer spring adjustment, your velocity woud have climbed another 5-10  fps. At that point,, more hammer spring would not gain any more velocity.....just make more noise and waste air. That would be the tip of your knee...or plateau.

Sooo... what your string is showing. Is your reg is set higher than your hammer spring has the energy to reach.

Lets say your hammer spring had enough energy to reach the plateau of 950fps . We like to tune to 95-97% below the max fps.  Which is in the neighborhood of 30fps. So for your current reg setting.... your gun would be optimally tuned to 920 fps.

Now.... to set your gun up to shoot at 850 fps. You need to lower the reg until its maximum velocity peeks out at 880-885 fps. And then drop the hammer spring back until your shooting your 850 target. That's where you'll get your best shot count for that velocity.
 
Hope that helps some. Others can explain it better.

[Firewalker]

Ok....forget about the word "KNEE" and think plateau.

From your shot string...you were getting very close to your velocity plateau.  Or top of your knee. If you had a little more hammer spring adjustment, your velocity woud have climbed another 5-10  fps. At that point,, more hammer spring would not gain any more velocity.....just make more noise and waste air. That would be the tip of your knee...or plateau.

Sooo... what your string is showing. Is your reg is set higher than your hammer spring has the energy to reach.

Lets say your hammer spring had enough energy to reach the plateau of 950fps . We like to tune to 95-97% below the max fps.  Which is in the neighborhood of 30fps. So for your current reg setting.... your gun would be optimally tuned to 920 fps.

Now.... to set your gun up to shoot at 850 fps. You need to lower the reg until its maximum velocity peeks out at 880-885 fps. And then drop the hammer spring back until your shooting your 850 target. That's where you'll get your best shot count for that velocity.
 
Hope that helps some. Others can explain it better.

Rod, freaking awesome!!!!  That's what I was looking for. I will pull her down tomorrow and turn the reg in 1 turn, Ill back out the HS to the same place and start another string.

[RDB]

1 turn is a massive amount for a reg adjustment.  Just go a quarter turn in. Then do a string like you did above with half turn adjustments with the hammer spring.

[Firewalker]

1 turn is a massive amount for a reg adjustment.  Just go a quarter turn in. Then do a string like you did above with half turn adjustments with the hammer spring.

Roger that!

Thank you again.

[Sfttailrdr46]

  David this is why I became a member here and also why I love to see new members getting the help they need without giving up on the hobby/obsession

[Firewalker]

David this is why I became a member here and also why I love to see new members getting the help they need without giving up on the hobby/obsession

AMEN, Don!

Simple, straight to the point, empathetic not apathetic. 

I think I'll take the time to use the good camera and document the parts as I disassemble the gun.

[Sfttailrdr46]

That's what I do whenever I take a new AG apart for the first time. At each step in the take down several pictures for reference, that way the reassembly is much easier. 

[Firewalker]

That's what I do whenever I take a new AG apart for the first time. At each step in the take down several pictures for reference, that way the reassembly is much easier. 

I did do that but poor lighting and just assembly pictures for an aid in putting it back together,  this time I want to document individual parts with the Nikon.

[mrbulk]

Ok....forget about the word "KNEE" and think plateau.

From your shot string...you were getting very close to your velocity plateau.  Or top of your knee. If you had a little more hammer spring adjustment, your velocity woud have climbed another 5-10  fps. At that point,, more hammer spring would not gain any more velocity.....just make more noise and waste air. That would be the tip of your knee...or plateau.

Sooo... what your string is showing. Is your reg is set higher than your hammer spring has the energy to reach.

Lets say your hammer spring had enough energy to reach the plateau of 950fps . We like to tune to 95-97% below the max fps.  Which is in the neighborhood of 30fps. So for your current reg setting.... your gun would be optimally tuned to 920 fps.

Now.... to set your gun up to shoot at 850 fps. You need to lower the reg until its maximum velocity peeks out at 880-885 fps. And then drop the hammer spring back until your shooting your 850 target. That's where you'll get your best shot count for that velocity.
 
Hope that helps some. Others can explain it better.

Rod, freaking awesome!!!!  That's what I was looking for. I will pull her down tomorrow and turn the reg in 1 turn, Ill back out the HS to the same place and start another string.

That explanation IS certainly awesome! And here I thought Rod was only known for the Elvis-like sideburns of his cool avatar...
Applicable for tuning most all regulated guns, Thanks!