Marauder tune made easier

[shorty]

MY tunes can be off a little bit sometimes. Typically around 50 fps.  That's why I usually give a couple tunes. If the 790 hit 865 then run the 700 fps tune and that should do it.

Can't be perfect, just get close.

[Busta Cap]

Shorty:   

.22 synrod. Fill beginning at 2500 desired fps 825-850 (bstaley mod)

.25 gen I Mrod fill 2500  desired fps 825-850 (extended air tube)

I have a 3000psi fill in my tank so I rarely get that. Many 2500psi fills


Thanks
Carlos

[shorty]

Busta Cap - Carlos,
Check out page 4. I set you up with a test tune there.

[rdhj]

Shorty:

Tried the 700 pfs tune and the first shot was dead on but the rest were a little higher...took five shots and got
789.8
798.7
794.6
798.8
803.0

Avg 797
ES 13.30
SD 5.19

Before I shoot an entire string using up pellets, I was wondering if, I should slow it down just a little more since three of these five shots would put me over 20 foot pounds.  It's possible that with an entire string the average would  be low enough to give  less than 20 foot pounds, but shouldnt i strive to have all shots under that?   what should I do to reduce the speed a little bit at this point?

[shorty]

RDHJ,
From here you will have to do the rest. I can only do the rough cut and you will need to fine tune.

Try a string out anyway to see how much of a curve you will get. If you don't like it then move on to the fine tuning next.

From where you are at now.
Hammer spring  (1/4") .5 turn cw will raise fps and allow for higher fill charge. CCW will lower fps and will work better with lower charge.
Hammer throw (1/8") .5 turn cw will lower fps. CCW will increase fps.
VAS .5 turn cw will lower fps and flatten out shot curve. CCW will increase fps.

I would start with VAS .5 turn CW. From where you are at now. So set the VAS to 2.

[rdhj]

RDHJ,
From here you will have to do the rest. I can only do the rough cut and you will need to fine tune.

Try a string out anyway to see how much of a curve you will get. If you don't like it then move on to the fine tuning next.

From where you are at now.
Hammer spring  (1/4") .5 turn cw will raise fps and allow for higher fill charge. CCW will lower fps and will work better with lower charge.
Hammer throw (1/8") .5 turn cw will lower fps. CCW will increase fps.
VAS .5 turn cw will lower fps and flatten out shot curve. CCW will increase fps.

I would start with VAS .5 turn CW. From where you are at now. So set the VAS to 2.

Well the results are in...I shot from 2500 to 1500 psi and got 36 shots with  a extreme spread of 36.1 and a SD of 11.5 and an average speed of 815.6 fps...here is the string

1   789.8
2   798.7
3   794.6
4   798.8
5   803
6   error
7   801.4
8   800.6
9   805.4
10   807.5
11   811.5
12   811.3
13   815
14   817.9
15   error
16   error
17   813.7
18   821.2
19   818.2
20   820.3
21   823.9
22   821.6
23   818.7
24   823.6
25   822.7
26   error
27   827.1
28   828
29   829.5
30   829.9
31   830.7
32   error
33   822.5
34   824.8
35   825.4
36   825.2


what do you think of this tune?   can this be improve any?  the speed keeps going up as i shoot and looks like it is just started to drop off at the end , indicating that I may be able to shoot to 100 psi possibly,  however 36 for a spread is kind of crappy, dont you think?

[shorty]

rdhj,
Now it's time to fine tune. Try this to lower the ES and increase the shot string,

Bring VAS from 2.5 to 2
Bring HS (1/4") from 2.25 to 1.75
Bring HT (1/8") from 2.75 to 4

This should bring you right below the 800fps mark and smooth it out.

At this point I am guessing. Although, this is really close to my gen 2 synrod (stock) tune for 40 shots / 797low 815 high.

My settings where:
VAS 2
HS 1.79
HT 4.27
2750 psi to 2050 psi.