Finally!!!! a shot curve on a Gen II with 850 fps avg

[FZ09]

OKAY Im really relieved with this one string. Before I get to excited I will test for repeatability later but I just had to share.
First let me suggest to anyone having issue with a marauder .25 Gen II that you take it apart to clean the hammer and cylinder well and re-lube with a dry lube. I used graphite. After my cleaning and graphite lube, I notice the cocking is effortless even with the new 12.5lb spring.

My marauder is a Gen II wood stock with adjustable comb in .25 cal.
Im shooting JSB exact kings 25.39g

My hammer spring is 2CW
My hammer throw is 7CW
My velocity meter screw is 5.5CCW
16 shot string
Fill pressure at 3000
End pressure at 2300
I really shot 24 total shots but the last 8 shots (not shown) decreased steadily down to 791fps.
I replace the OEM hammer spring with the aforementioned 12.5lb hammer spring.

Behold..... a curve!




graph below

[FuzzyGrub]

There should have been no reason to go to a 12lb spring to get that curve. That should have been easily achieved with stock spring. ???

[Roger]

I agree, my stock gen I is very close to what he posted. I am getting ready to change my spring to the #10.

Roger

[jhm757]

There should have been no reason to go to a 12lb spring to get that curve. That should have been easily achieved with stock spring. ???

Yes! My completely stock .25 SynRod shoots a very similar string with an average of 856 fps.

However that is with a 3200 psi fill.

Jim - jhm757

[Bigtwin69]

Jim, I've got a new SYnrod 25...what are your settings?

Terry

There should have been no reason to go to a 12lb spring to get that curve. That should have been easily achieved with stock spring. ???

Yes! My completely stock .25 SynRod shoots a very similar string with an average of 856 fps.

However that is with a 3200 psi fill.

Jim - jhm757

[Bigtwin69]

Thanks for the info and time taken to note the data.

OKAY Im really relieved with this one string. Before I get to excited I will test for repeatability later but I just had to share.
First let me suggest to anyone having issue with a marauder .25 Gen II that you take it apart to clean the hammer and cylinder well and re-lube with a dry lube. I used graphite. After my cleaning and graphite lube, I notice the cocking is effortless even with the new 12.5lb spring.

My marauder is a Gen II wood stock with adjustable comb in .25 cal.
Im shooting JSB exact kings 25.39g

My hammer spring is 2CW
My hammer throw is 7CW
My velocity meter screw is 5.5CCW
16 shot string
Fill pressure at 3000
End pressure at 2300
I really shot 24 total shots but the last 8 shots (not shown) decreased steadily down to 791fps.
I replace the OEM hammer spring with the aforementioned 12.5lb hammer spring.

Behold..... a curve!




graph below

[johnw.]

some of us with Gen 2 have gotten rifles ,that from the factory were starting out in the low 700 f.p.s. range ,mine 712 f.p.s. ,yeah the shot string was consistant for 2 mags but in the 700 range??In reading posts it seems that you shouldn't really compare Gen 1's to the Gen 2's,...the guys stating their getting 850 average with their Gen 2's but after going above the 3000 p.s.i. mark!,...I'm sure in time and much trial and error we'll get the problems taken care of for us with slower guns but just consider its not just one of the Gen 2 owners having lower velocities ,it seems there are several of us-I installed the WAR valve and am getting over 900 f.p.s with JSB's to start with but need to experiment more with my settings to get a decent shot curve-johnw.

[FuzzyGrub]

some of us with Gen 2 have gotten rifles ,that from the factory were starting out in the low 700 f.p.s. range ,mine 712 f.p.s. ,yeah the shot string was consistant for 2 mags but in the 700 range??In reading posts it seems that you shouldn't really compare Gen 1's to the Gen 2's,...the guys stating their getting 850 average with their Gen 2's but after going above the 3000 p.s.i. mark!,...I'm sure in time and much trial and error we'll get the problems taken care of for us with slower guns but just consider its not just one of the Gen 2 owners having lower velocities ,it seems there are several of us-I installed the WAR valve and am getting over 900 f.p.s with JSB's to start with but need to experiment more with my settings to get a decent shot curve-johnw.

That suggests that there is a defect or build error. Any stock Gen I or Gen II 25 cal should be able to reach 850fps with Kings. If only in the 700's would look to return it, or fix it, vs throwing aftermarket parts at it, in hopes of fixing it. You weren't even at 30FPE. This gun is advertised as a 50FPE gun (peak), and easily achieves the 40FPE for 16 shots.

FWIW: I purchased one of the early Synrods in 25 cal. I'm no tuning genius, but got a 860 - 870 - 860, 16 shot string and have left it there. That is a 3Kpsi fill based off of the guppy gauge. I am sure it can get more, but liked the very low Es. ie the settings were not near max preload or quite full open on velocity.

The most likely build error, is they installed a 177/22 TP instead of the 25 cal one. The ID should be 0.140". If not, just drill to that. Also, could have a Gen I spring, but don't think that would cause that much of a decrease. Gen II spring wire diameter should be 0.051".

Now defects is a much larger list. Hammer/tube/sear interfaces, burrs or debris in valve passages, TP seals, etc.

[jhm757]

Jim, I've got a new SYnrod 25...what are your settings?

Terry

HS-6, HT-2, VMS-5

Gun is all stock, filling to 3200 psi.
Current String:
1. 853 9. 863
2. 852 10. 861
3. 851 11. 861
4. 856 12. 861
5. 862 13. 861
6. 858 14. 849
7. 858 15. 847
8. 864 16. 848

Hi 864 Lo 847 avg. 856 ES 17

Jim - jhm757

[FZ09]

Im the original poster.

My very first shot string with this gun:
715.1
Err 1
Err 1
Err 1
Err 1
702.2
698.4
691.3
699.7
693.8
693.0
727.8
690.9
717.4
680.9
676.5

This gun is advertised at 900fps for .25 cal and it is nowhere near that from the factory..
What good would complaining do? What good would it do for me to have this returned only to get another gun in-hand that produces the same results.

There is a disclaimer/ quote from the owner manual on Pyramid airs page in the description about this gun:
"The owner's manual states this about fill pressures: "The Marauder has been factory set to an efficient fill pressure that will suit most hunting and target uses.""

So the gun is advertised to 900fsp but factory set (in my case) to ~700fps. Thats a 200 FPS difference from what is advertised. I guess the devil is in the details because the advertised velocity doest not stipulate FPE or ammo used.

I think complaining to Crossman will get an individual nowhere; however, a trend of negative reviews of the current model can initiate a change. I intend to let my review of this gun reflect the amount of intervention needed to get this gun working at a level of performance that prevents me from wrapping it around a tree. I do not have the time or the patience to play magical chairs with gun exchanging via returning, packing and shipping ,phone calls, and emails.

Crossman should factory tune these to the advertised 900fps of at least 8 shots!

On a brighter note: My 15 yard accuracy is great! I have only shot at 15 yards because it has spent its entire life (7 weeks) in my basement range being tuned, SO I have long range accuracy testing results to ponder soon