Q:

Fuxineering My Vulcan 0.22 from Talon Tunes

Thanks to the old timers here, I am starting to get my recently arrived Vulcan 0.22 from Tony readied for use.
My apologies if I don’t credit people correctly. Still trying to learn who is who.

Mine is a 2015 June production with an odd configuration of features. It has the multi part baffle shroud like the new guns, but lacked a depinger on its hammer spring, had the old style two hole HST adjuster like the older production, but like the current guns came with no hard case.

First order of business was getting its safety to actually engage. It would only partially engage and if one pulled the trigger a little harder, the blade would slip past safety and fire the gun. Turns out the trigger blade didn’t leave enough clearance for the safety plate to slide between it and the frame. The safety was just barely engaging the trigger blade and would refuse to slide further back. It was working more like a sear than a safety. Adjusting the linkage rod tension got a bit more clearance and after running the safety back and forth it now actually engages. Currently, the safety is stiff, but I put a tiny dab of moly grease and it is gradually working looser. I guess I could grind the safety plate thinner, but that means taking apart more stuff that I want to do.

Next, I turned to Hoot’s shroud vent mod. On my particular shroud, the front cap was easy to unscrew with a lens wrench.
The rear cap wouldn’t budge, so I did all the work only from the front and didn’t try removing the back flow baffle (rearmost element)

Here we see all five baffles, their intervening O-rings and the front cap

While I had things apart, I grabbed a few measurements. The baffle opening is 0.243.
The front cap opening measured 0.258
Given that a 0.30 wouldn’t fit, I’m guess the baffles and cap different for the bigger caliber version.
Then again, we see SniperQTY happily swapping barrels of different calibers on U-Tube.
Don’t know if he also swaps the shrouds.

Shroud outer diameter = 1.130
Shroud inner diameter = 1.116

I used Donny’s tape method to protect the shroud and allow easy marking of the desired hold locations.

An auto punch makes easy, accurately divots in the aluminum tubing. If you are still using an old style center punch,
do yourself a favor and get an auto punch. I kick myself for not getting one years ago.
Mine is a Lisle 30280 Automatic Center Punch. Works great.

A few minutes at the drill press and 1.0 mm holes were done.

UPDATE/ my shroud’s rear holes are now 1.0 mm and forward baffle holes 1.5 mm /UPDATE

TIP: since this is only aluminum, use 90% isopropyl alcohol to lubricate and cool the bit instead of cutting oil.
Cleanup is a LOT easier without oily residue.
(That would be the high concentration stuff, not regular rubbing alcohol)

Deburring the inside of the drill holes was done with a piece of all thread.
I taped most of the rod to limit what portions were sharp. A few passes and
all the burrs were gone. The baffles slipped easily back into place.

Finally, the vented shroud ready to install. I used an O-ring like Hoot said to secure the shroud in the desired spin.
You can’t even see the vent hols with the shroud spun to position
the holes between the shroud and barrel.

Muzzle report was now much quieter than the hammer slap and ping. Hmmmmm. was it possible that my new Vulcan didn’t have a factory de-pinger?
The lack of a hard case suggested it was a later gun, but the old style HST adjuster made me suspicious.
Opened up the access panel and sure enough —— no de-pinger at all.

Since I had to take it all apart, I went ahead and polished the hammer. Took just a few minutes with a dremel, felt wheel, and all metal polish.

Tried ONE grommet in the position that the factory places their de-pinger.

BTW, nobody quite explains how to get the whole assembly back into position.
You can’t push the spring and grommets through the adjuster hole.
Compressing the spring and hammer all together and squeezing
everything in from the side threatens to bend the hammer spring.

Here is how I did it without stressing the spring or scratching up the hammer.

1. Detach the cocking spring
2. Put the hammer, brass guide, and grommets together WITHOUT the hammer spring.
3. Insert the hammer assembly
4. Push the hammer spring in from the back. When you have enough pressure, the
grommets pop onto the spring. Then you simply spin and ease the grommets into position.
5. Reattach cocking spring
6. Insert HST adjusting plug.

Still pinged too loudly for me with one grommet, so back apart it went and I put on a second grommet.

Two grommets made the ping a bit softer. The hammer slap is now the loudest noise. Overall, the noise level has gone from loud as my Benjamin NP2 to about half as loud.
Mind, you, it is far from silent, but it is a significant improvement from how the gun arrived and worth the effort.
A delrin spring guide may be in my future.

EDIT: I have since gone to one grommet and a rubber cap over the brass bushing. See later in this thread.

Thanks all again for the info on this forum.

Guy

Airgun Technology

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Viewing 10 replies - 61 through 70 (of 70 total)

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Kris,
The shroud endcap threads lined up with my 1.0 Metric Thread Screw Gauge.
Hope that helps

thanks, I see. well I still believe anything interfereing with the hammer spring is a bad thing.

Kris here’s a picture of what I did yesterday. One grommet really made it quiet. Two grommets even made it quitter.

have you done the drilling holes mod on the shroud baffle the one where the barrel screws into?

to be really effective you have to offset the shroud i.e. do not screw it all the way back in because the barrel end will go past the holes. but you need to put some plaster or Teflon tape on the threads to make the the shround hold firm.I was following Hoots advice on that bit, but used a round file instead with a just right diameter. much better finish.

I have put a hair curler with felt to the rear end too.

what you can also do, I installed a different screw with a square head and a spacer, this is for the linkage spring, now on my gun the hammer spring and the linkage spring don’t touch anymore so should not resonate. I talk about the screw which directly compresses the long thing spring against the action. seems to work for me.

can you show us the grommets fitted. cant see a picture with 2 on.
cheers

I did try to fit a hw100 silencer endcap (mine has a much smaller exit hole on that one) but you are right it did not fit. any idea what is the shrouds exact thread size, still want to add an extension on it. for you in the us maybe not legal so no idea. here we can have anything on but the power is lame.

Very nice white up and very Vera picture.
Just wonder about using grommets on the hammer spring. In any PCP we used to polish the hammer, smooth the springs ends and avoid using any grease to make the gun very consistence and reduce FPS spread but here we are fixing something to the hammer spring which in theory may affect consistency.
Now I have no figures to proof this and I hope it will not affect the gun performance as I want to do the same for my Vulcan.

So to be clear the set screws have to be removed to get all of the baffles out? When you put them back in how do you know they are in the right place? Or are those set screws simply a stop so that last baffle can’t move backwards?

DonnyFL, I don’t have a Delren bushing. Deciding whether to make one. I think I would want its OD to be like the brass one to preserve the free floating hammer hit, but that means the piece would have to withstand quite a beating as it stops the spring’s forward travel.

I read about the Depingers inside the air tube, but still too scared to do that degree of disassembly. Also, why isn’t there a concern with vinyl pieces being a fire or explosion risk when exposed to 250 bar air? That would seem a recipe for disaster having a flammable material in pressurized air.

benj397, here is the spacing I used. I got the spacing by positioning the removed stack of parts next to the shroud tubing.

Be warned that if you don’t remove the pieces before drilling, you will almost certainly damage them and lock
them into place with burrs. I strongly recommend you pull the baffle pieces before drilling.

I used a 1 mm drill. That means I can enlarge them later if desired. Just as Hoot has described, one hole for the center of each baffle.

Then 8 holes to vent the rear. My 8 holes start 2 cm from end and are spaced every 0.25 inches.

The shroud tubing unscrews from the barrel. You can then pull it forward until its rearmost O-ring engages the barrel threads. Unscrew the O-ring over the threads to free the shroud.

Those set screws appear to hold the back flow baffle in place (the rearmost one)
They don’t hold the shroud to the barrel

The size of O-ring to hold shroud position after the mod isn’t critical. It just has to slip over the barrel and get squished as the shroud is snugged.

So, it looks like there are 8 holes on the breech end and 5 on the exit end.
Is this the correct # to use?
How far from the breech end should the first hole be (cap removed and not used in measurement)?
Distance between the 8 holes?
How far from the exit end should the first hole be (cap removed and not used in measurement)?
Distance between those holes?

I have gripped the shroud and tried to turn it. No go. I didn’t try to force it. I see there are a couple set screws. Do these hold the shroud to the barrel or simply hold the baffles in place?

And what size o-ring is needed when putting the shroud back on to help lock it in place with the holes underneath?

Again nice write up Guy. Looks like your grommet is ruffed up some?? Two grommets made a difference to me.

Nice write-up Guy. The brash bushing is your main culprit for the loudness. Ernest’s delrin piece makes a very noticeable sound reduction. I am dealing with extreme spread in fps so I am going to try to remove it and see if it helps. In my opinion if you have the delrin piece, you won’t need any grommets. With an LDC on it’s super quiet. You may also need the depingers (2x) in the air tube. I can’t speak for the effectiveness of the delrin piece in the .25 version but for the .22 it is awesome 🙂

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