Marauder Pistol bstaley tune farting air?

[Ribbonstone]

That's the way....clear goals keep you from getting side tracked.  Do think you can manage those shot counts and stay under 4% varation doing it.  Using the o-ring mod might help....but think you might have to change the stack height (or hardness).

Actually, think with enough experimentation (not modification....but a careful, recorded adjustment of adjustments) could manage the goals without the O-rings.

I could "cheat" and feed the thing 18- 21gr. pellets. Same setting that manages 15foot pounds with 14.3gr. will make 16 foot pounds with 18-21gr. pellets....and usually ad one or two shots to the 4% shot count.

[drummerboy7816]

So I think I'm starting to get a hang of this thing.. Starting 3,000 PSI, I'm finding to get my sweet spot starting at that range, my spring needed to be at around 5 turns CW, then I start messing with the HT for velocity.  Here's a sweet string for around 12.5 FPE (1 HT, 5 HS):

#   FPS   FPE   PSI
1   559   12.58280146   3000
2   554   12.35871331   
3   556   12.44810697   
4   556   12.44810697   
5   565   12.85436489   
6   556   12.44810697   
7   560   12.6278607   
8   560   12.6278607   
9   565   12.85436489   
10   556   12.44810697   
11   560   12.6278607   
12   566   12.89990734   
13   562   12.71822077   
14   554   12.35871331   
15   558   12.53782276   
16   564   12.80890299   
17   558   12.53782276   2300
18   554   12.35871331   
19   560   12.6278607   
20   564   12.80890299   
21   566   12.89990734   
22   561   12.67300047   
23   558   12.53782276   
24   562   12.71822077   2000
 
24 shots @ 2.1% ES, pretty nice, should of gone longer to see how low it will go but I stopped.  Using this, I tried again at the 16 FPE (1.40 HT, 5 HS):

#   FPS   FPE   PSI
1   624   15.67916418   3000
2   630   15.98213619   
3   624   15.67916418   
4   631   16.0329134   
5   631   16.0329134   2800
6   628   15.88082338   
7   633   16.13470942   
8   636   16.28800746   
9   633   16.13470942   
10   630   15.98213619   2500
11   626   15.77983271   
12   628   15.88082338   
13   626   15.77983271   
14   626   15.77983271   2300
15   626   15.77983271   
16   619   15.42890221   
17   617   15.32936116   
18   617   15.32936116   
19   614   15.18065361   
20   610   14.98350435   
21   607   14.83648803   
22   599   14.44798803   2000

Really nice inside 16 shots 2.7% ES, but seems like I run out of the sweet spot around 2200 or so.. with this set up, not sure if I can get that magic 24 shots.  I'm starting to think the 1.25 TP is causing me to use more air then needed at this FPE.  Hopefully the 1.05 TP from hillairgun will make it run more efficient!  But I feel pretty good getting this ES, never happened before in any setting so that's a step in the right direction   

[FuzzyGrub]

Thanks.  It's a good thing I do enjoy the scientific process   I bought some vibra-tite to toughen up the adjustments, hopefully that'll keep it in tune once I get the settings sorted out.  My goal is to have it set up 20 PFE for 16 shots, 16 FPE 24 shots, and some absurd shot count for like 10-12FPE plinking, just by adjusting the HT and all under 4% ES.  That would be success for me.

I have achieved your two higher powered strings with BSB on Prods.  I never tried the lower powered tune, but many others have. 

I found that vibra-tite did not work on the throw adjustment.  As soon as you adjust it again, all the vibra-tite just peels off.  Works better on the HS adjuster where the threads are more "loose".   If yours is having problems holding, you can tap the front hole on the hammer for a set-screw, and insert weed eater line (small piece) and lock it down.  You do have to be very careful you can break the tap off. 

PS: the O-rings went out in the AM mail.

[Frank in Fairfield]

I know this tune/post is about the PRod but I have my results on my 1720T.
I just wanted to be at or near 12fpe for possible FT use.
This one is close.
If I go to a 10.34 grain pellet I exceed 12fpe and the speed drops to around 800fps..

[drummerboy7816]

Thanks.  It's a good thing I do enjoy the scientific process   I bought some vibra-tite to toughen up the adjustments, hopefully that'll keep it in tune once I get the settings sorted out.  My goal is to have it set up 20 PFE for 16 shots, 16 FPE 24 shots, and some absurd shot count for like 10-12FPE plinking, just by adjusting the HT and all under 4% ES.  That would be success for me.

I have achieved your two higher powered strings with BSB on Prods.  I never tried the lower powered tune, but many others have. 

I found that vibra-tite did not work on the throw adjustment.  As soon as you adjust it again, all the vibra-tite just peels off.  Works better on the HS adjuster where the threads are more "loose".   If yours is having problems holding, you can tap the front hole on the hammer for a set-screw, and insert weed eater line (small piece) and lock it down.  You do have to be very careful you can break the tap off. 

PS: the O-rings went out in the AM mail.

Thank you!!

That’s good to know.  Throw is already pretty tight it seems so hopefully that will hold.  The spring is indeed the one that needs some help holding place

[drummerboy7816]

Alright, found a setting that made me plenty happy!  I ended up using 2 "X-rings" o rings that John (Fuzzygrub) sent me with a washer in the middle of them (got that idea from another post), .045 spring, 0 turn HT and 0.5 turn Spring.  The washer seemed to take away a lot of the hammer bounce/farting at lower PSI I used to get below 2,000 with just o rings. 

Here's what I got:

#   FPS   FPE   PSI
1   623   15.63   3100
2   633   16.13   
3   641   16.55   
4   648   16.91   
5   640   16.49   
6   643   16.65   2800
7   648   16.91   
8   656   17.33   
9   653   17.17   
10   664   17.75   
11   661   17.59   2600
12   664   17.75   
13   664   17.75   
14   664   17.75   
15   672   18.18   2400
16   669   18.02   
17   672   18.18   
18   664   17.75   
19   669   18.02   2200
20   664   17.75   
21   661   17.59   
22   661   17.59   
23   659   17.49   1900
24   653   17.17   
25   659   17.49   
26   646   16.80   
27   643   16.65   
28   641   16.55   1600
29   638   16.39   
30   626   15.78   1500

From shots 3 through 28 (3000 psi to 1600 psi), gave me 26 shots at 17.4 FPE with 4.8% ES, can't complain    Going to put some vibra-tite on the spring screw to lock that in and call it a day o this gun.  My first PCP and already itching for the next one..

Thanks all for the help and great discussions (especially to John for the generosity!!).  Truly a great forum!   

[FuzzyGrub]

Glad to see you got it tuned to where you want it to be.   

[triggertreat]

Nice bell curve Ben and glad you're happy with it.  John is our resident Prod guru and has always been willing to help a fellow member.


I believe a Marauder would be a good one to put on your list for your next gun.  They are truly awesome and versatile guns and tune very similar to the Prod.

[drummerboy7816]

The Synthrod is definitely on my list, but in my current house, my yard is small (10 yards max distance from side to side..), don't think I can really have fun with a Synthrod's at that range.  That's why I originally went with Prod (shooting from inside my house to end wall of yard is about 15 yards, which prod does great in).  Shooting "at" rats in my backyard is fun too with the nimbleness of the prod (haven't got one yet).   Was using a bugbuster scope, but couldn't lock on target fast enough in close quarters that is my small backyard.  Just got some reflex sights which seems like it will work better (plus with 17 FPE for a rat.. probably don't need to be too accurate)  .   

In Southern California, unfortunately there's not a lot of open outdoor places I know of that I can just go set up targets and shoot..   

[triggertreat]

Yeah, a Synrod would be too much and too big for 10 yards ratting IMHO.  Oh well I tried, lol.

[drummerboy7816]

Your Synrod numbers look amazing though    Maybe one day when I get a bigger yard I'll venture down that path.