.22 Marauder barrel?

[JDShapp]

I finally got around to trying some fine tuning on the SSG today. First I tried for the 860fps range, found out that it gave me a rapidly descending string. After some experimenting I settled on a setting that gets near 830fps for around 20 shots, and has roughly 40 shots above 800fps. Definitely some improvements on power and shot count on it compared to what it was when I got it.

 

[NorthLand43]

"JDShapp"I finally got around to trying some fine tuning on the SSG today. First I tried for the 860fps range, found out that it gave me a rapidly descending string. After some experimenting I settled on a setting that gets near 830fps for around 20 shots, and has roughly 40 shots above 800fps. Definitely some improvements on power and shot count on it compared to what it was when I got it.

May I ask what was your settings using the SSG? Sounds about where I want to be (i.e. 30 shots above 800fps).
My settings seem to follow yours of the 860FPS and then descends to about the lower 700 in 30 shots (avg of 795).

 

[JDShapp]

I think its about 2 or 3 threads in on the slotted bolt. As for the large hex sleeve I started off with it screwed in until it touched the nyloc nut and then began backing it out slightly until I found the spot I was comfortable with. Of course things could be different for your rifle.

 

[NorthLand43]

"JDShapp"I think its about 2 or 3 threads in on the slotted bolt. As for the large hex sleeve I started off with it screwed in until it touched the nyloc nut and then began backing it out slightly until I found the spot I was comfortable with. Of course things could be different for your rifle.

Thank you JD!

Seen a few more threads on polishing barrels and might give it a go. 

 

[JDShapp]

Tonight I ran some shots over the chrono. The shot string is a little flatter now, but I still see the descending shot string there at 3k down to 2k. I'm thinking I might have to do some adjustments to the valve metering screw and see if I can't fix that.

 

[NorthLand43]

"JDShapp"Tonight I ran some shots over the chrono. The shot string is a little flatter now, but I still see the descending shot string there at 3k down to 2k. I'm thinking I might have to do some adjustments to the valve metering screw and see if I can't fix that.

The impression I initially got reading about the SSG in other sites is it was basically a drop in mod. Then, with some additional reading, the SSG needs some tuning to get it where you want it. No one seems to have a good definition on what the settings to get a given tune/FPS/Shot count is (i.e. if you increase this many turns on the guide rod you get X, or if your turn the end cap hex screw you get Y).
So, I started using the depth function on a set of dial calipers to measure from the end of the guide rod to the top of the locknut (note, going across the cross slot on the guide rod). 
Need to go back to it, but life happens while you are making other plans.

 

[JDShapp]

Only reason I'm even thinking about the valve is this rifle is a refurb to begin with and at a quick glance last night it looked like the brass set screw that is over the meter screw was missing. The good thing though is if that set screw is missing I have a replacement on hand already. 

 

[JDShapp]

Alright, tonight I did some work. Opened up the VMS screw 2 turns out and really started making the SSG do the work for once. I can make the gun run hotter now with the 18.1gr pellets, but there really is no need. This is what I got for my efforts tonight. I apologize for the long string that's about to be shown.

3k to 1.9k psi(rifle gauge)
49- 803
48- 807
47- 813
46- 813
45- 816
44- 819
43- 818
42- 826
41- 827
40- 829
39- 829
38- 827
37- 827
36- 830
35- 832
34- 838
33- 834
32- 838
31-838
30- 838
29- 839
28- 844
27- 838
26- 840
25- 838
24- 847
23- 839
22- 840
21- 840
20- 847
19- 842
18- 836
17- 844
16- 839
15- 840
14- 837
13- 838
12- 843
11- 835
10- 838
9- 836
8- 830
7- 839
6- 826
5- 825
4- 821
3- 821
2- 819
1- 814

 

[NorthLand43]

JD, that is exactly where I want mine! 
I did adjust the end cap hex screw yesterday: From once it stopped leaking air, I back out one full turn. THERE I began to feel where it was supposed to be, i.e. it was very quiet. From what everyone else has said, once the SSG is tuned in the zone, it is very quiet. 
Maybe a few more turns and I will be set.
Will try to do some testing today . . .

 

[NorthLand43]

Based off JD input, I backed the locknut to 0.120 (using the depth function on a dial caliper) on the guide rod.
The end cap hex screw, I started about half a turn from when the air stop bleeding out. I think it was still shooting too hot, as I was running it across a chrony. Backed the hex screw another half a turn (full turn, maybe a bit more). 
Starting at 3kPSI I got 24shots (chrony threw a few error1) recorded, ended at 2200PSI. 
All were above 800FPS.
More later.

 

[ajshoots]

In regards to the VMS adjustment. I have had the best luck running it wide open and using other adjustments to tune. There is a reason that the best 2 aftermarket valves have NO vms adjustment!!

 

[JDShapp]

After running over 500 pellets though the barrel I figured it was time to give it a good cleaning. Next up I'll see how crosman domes fair in it, and next week I'll get to see how polymag shorts do.