First time reg adjustment

Screwing the screw in (clockwise) turns the reg down. Or, the less space inside the washer chamber lowers the reg pressure.

I measured from the face of the reg to the face of the set screw and worked from there, 1/4 turns at a time.

My reg cam set at 0.200″ (face of screw to face of reg). My first adjustment was the wrong way to 0.180″ (one half turn out) this gave me 1000fps (from the 890’s).

My final reg adjustment was 0.230″ (3/4 turn in from factory). I found each 1/4 turn to be roughly 0.010″.

At 0.280″ (two turns in) the rifle would not work properly (500fps or less) and I had real difficulty getting all the air out (I think the bellvue washers were binding and would not flex and allow air to fill the reg chamber).

So for my rifle (177 standard) each quarter turn wads about 50fps. Mind you I shortened my hst spring early on (I regret this now).

To find my reg setting I did the following.

I loosened the spring at least one full turn from where the fps were that I wanted (it may take more depending on how the reg is set) and began shooting ten shot strings..

String #1
848.8
859.4
848.5
860.1 (max)
849.9
852.2
846.1
847.8
855.3
843.1 (min)

Max spread 17fps, avg velocity 851.6fps.

1/2 turn in on the HST.

String #2
898.0
897.1
901.2
903.6 (max)
894.6
899.2
901.4
903.3
895.8
892.9 (min)

Max spread 10.7fps, avg velocity 898.25fps. About a 50fps jump from string #1.

1/2 turn in on the HST.

String #3
951.2
952.2
949.1
950.4
951.5
955.2
956.5 (max)
948.6
946.7 (min)
951.4

Max spread 9.8fps, avg velocity 952.1fps. About a 50fps jump from string #2.

1/4 turn in on the HST (decided that a 1/4 turn at this point to the end was probably more accurate).

String #4
971.8 (max)
971.1
965.0 (min)
967.3
965.9
965.6
968.7
971.5
967.2
966.3

Max spread 6.8fps, avg velocity 968.4fps. About a 15fps jump from string #3.

1/4 turn in on the HST.

String #5
981.7
982.4
985.7
975.7 (min)
985.1
984.5
987.2 (max)
987.1
986.8
983.5

Max spread 11.5fps, avg velocity 981.5fps. About a 15fps jump from string #4.

1/4 turn in on the HST.

String #6
992.9 (max)
985.5
990.9
990.0
985.1 (min)
992.5
992.1
992.8
992.8
989.2

Max spread 7.8fps, avg velocity 989.0fps. About a 10 fps jump from string #5.

1/4 turn in on the HST.

String #7
994.5 (min)
999.1
996.8
996.5
998.8
994.9
997.1
999.3 (max)
997.0
997.2

Max spread 4.8 fps, avg velocity 996.9fps. About a 10 fps jump from string #6.

1/4 turn in on the HST.

String #8
1003 (max)
996.6
999.5
1000
1001
999.9
993.6 (min)
1000
1000
997

Max spread 9.4 fps, avg velocity 998.3fps. About a 2 fps jump from string #7.

From this I figured my reg was set to shoot my pellet of choice at 1000fps. I wanted somewhere around 880fps, with the ability to go from about 850 to 900 for tuning.

So 3/4 of a turn in on the reg got me where I wanted.

The reg is set too high and trying to compensate with the hst will give you a large velocity spread.

Sounds like something went sideways when you adjusted the reg if you ‘lowered’ it and are getting 1200fps. 😯 😯

Mine was very consistent, if I lowered it the velocity would go down when I plateaued the hst adjustment.

thats ok…. kinda fig something got mixed up…

If it was me… i would turn your HST up a little bit take a couple shots document them.. turn it up some more take a few shots document them… keep doing that till you find where the FPS plateau’s and won’t raise no more. Thats where you want the HST for that current regulator setting Right at peek kinda right before the string stops rising… but not over (just wasting air).

so once you find that you will know where a bouts you sit with the reg setting. Lets say you don’t adjust the reg and you set your HST to the optimal setting and its shooting 870….

well then yah gotta bump your regulator down a touch. and then find that optimal spot for the HST.

keep going until you get it to where you want.

then run a full string to see how it looks.

you will have a range with your HST. but the further away you get from that optimal zone the wider the FPS spread will get and so on….

its kind of a balancing act.. but once you get the hang of it.. it gets easy.

I know the combro probably doesn’t make running strings easy… can’t that be hooked up to a laptop ??

did yah read the whole post i made???

A bit of a long thread, but it is really helpful with good advice from OG and Endo in there.

http://www.talonairgun.com/forum/viewtopic.php?f=22&t=22808

I often refer back to it myself for sage advice when digging in the bowels of the reg.

Hope it helps,

The Cad

Your gonna have to provide more info…

for starters
how many fps is it shooting?
whats your reg set at now?
post a shot string.
how many fps are u looking to shoot at?
what pellets?