Q:

Vulcan .25 upper fpe level, and the existing valve/reg…

:hoot:

So, the Vulcan .22 produces around 37 fpe. Rather high for a .22 caliber!

The .25 produces about 48 fpe. A tiny bit below average for a .25 caliber. Notice no one seems to admit to getting more power than this from the .25.

Does this mean the Vulcan uses the same power-plant on both rifles? That would make sense in looking at the fpe results. Dialed down for .22, produces above average fpe. Dialed back up for for .25, produces acceptable fpe. Or…is it simply too loud at higher velocities? There must be a reason.

While it’s not a problem or complaint, as 48 fpe should be plenty for normal .25 usage, I would be interested in your comments?

Hoot:

Meanwhile, back at the Radio Ranch:

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Airgun Technology

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Viewing 5 replies - 1 through 5 (of 5 total)

Hi guys

Vulcan 9 days and counting.

Having been recently involved with my misbehaving from new Monsoon and lengthy discussions with Frederick, Johan and a factory engineer. The factory response to more power ie velocity is more wear . On everything. More noise. My input would add for what benefit? With the right balance of pellet, weight , fill pressure. Accuracy, good shot count and easier shooting is obtained.
Many years back I had a Weihrauch HW80 . About 11.5 FPE in .22. Lusted for more power, spring change to “Power of an Ox”. Wow 18fpe. What a dog to shoot, jumping all over the place and more noise than Concorde with full after burners . Horrible. The pigeons on hangar roof laughed , local aerodrome with permission to reduce their numbers.
In my humble opinion having shot airguns with less than 12fpe is challenging and rewarding. A .177 Air arms I had years ago at -12fpe shot loads of rabbits at 40 to 60 yards some at 75 yards . Head shot prone with bean bag or bipod , laser range finder . I put up range sticks with little coloured flags near their various favourite spots. I am not a good shot.
Point is you only need 1.6 FPE to kill a head shot rabbit. Probably less for most smallish birds.

Why the lust for more power all the time? Makers of guns just like car companies produce an item to work well within an envelope. Take them outside of their design limits produces substantial knock on effects.
Eg car with much more power will need better brakes, better tyres etc.
I guess however that a lot of people like the tuning side almost as much as the shooting side.
PC owners are a case example.
The French have a saying ” Chacun a son gout” , everyone has their taste.

Safe shooting

Good info Soze.

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I played with my Vulcan. The gun can be turned up. It is not maxed out at 50 fps. I turned mine up to 970 and it still had room to go on the HST. I stopped because the hammer noise was immense. The gun also jumped when fired. The Vulcan .25 is an awesome gun but it’s not without it’s faults. I have found the gun to be hard to shoot consistently. I have put the gun in a vice and have seen groups that would make the most discerning airgunner smile. The gun if properly shot will one hole at 50 yards and it will maintain sub MOA to 150. The problem is the gun doesn’t want to sit still when fired and it is even more pronounced when the speed is tuned up. So I settled on 925 which is still a good speed for long range shooting in the .25. I also experimented with speeds as low as 880 and I found the noise from the hammer significantly reduced and the gun was super easy to shoot well. I also gained 2 extra magazines. Sometimes I think I am too speed obsessed, logically I know there is little difference in take down power from 43 foot pounds to 48 foot pounds but I have decided to practice with the Vulcan set a 48 foot pounds for now. I know the gun could push 60 foot pounds but that energy would come at a high cost. The pellet did remained stable out to 970 but I decided the juice wasn’t worth the squeeze.

Per the book the .22 reg is set at 140 bar and the .25 at 150 bar. My .25 came shooting around 42#. A complete turn of the hammer spring tensioner brought it to 52#. Sound didn’t change much. Didn’t try turning it up further so can’t say what would happen. But considering the size I would think 55+ fpe quite a bit to ask while maintaining a decent shot count.

I don’t know how a Cricket bullpup compares to their Carbine but my Cricket Carbine shooting like velocities, or any velocity for that matter, is quieter than my Vulcan.
The Vulcan isn’t bad but has a untuned springer twang component to it.
To be clear I love my Vulcan.

Dear uncle Hoot
I want to touch on the potential sound out of a Vulcan at higher FPE. I had the opportunity to shoot a 25 cricket that shot kings at 860 fps. My Vulcan last time I checked is 925 and there was almost no difference between the two guns. We had someone stand 20 feet in front of guns (and to the side of course) as I said before Vulcan is ways quieter than cricket and would not be a problem with 950-980 fps. At that point I would guess it would be as loud as my cricket at 900

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