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

All Replies

Viewing 15 replies - 46 through 60 (of 70 total)

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Guykuo, you are persistent. Good going :thumb:
What caliber, fps, and SD are you working with ❓
I tried to tuneing my .22 down to 890ish but the fps spread increased. I set it back to 910 and it worked grear. Let it sit for several days and the fps for 10 shots went up to 920ish with 4 duplicate readings in a row. 😯

I didn’t hear much difference with the cocking lever spring disconnecred and held out of the way but the factory attempts to answer the problem have been directed at holding the two springs apart with assorted rubber or plastic.
The cocking and fireing was moving my centered grommet and it may have reduced fps more in the center. I need to test more with the two grommets at the ends as the last few I shot had bumped up 10 fps from my previous test. Maybe it’s the erratic temperatures here ❓

The fixes continue. I have some other threads describing cleaning out the breech body brass swarf and tightening the bolts holding the cocking rod to that same breech body.
http://talonairgun.com/forum/viewtopic.php?f=54&t=33499

I have gone back into the shroud and increased the size of the air stripper’s back flow holes. That pretty much it for the shroud.

It was time to revisit the hammer and inspect how my brass bushing’s rubber cap (10 ml BD syringe rubber seal)
is holding up after a couple hundred rounds.
Retracted the spring to reveal the front of the cap. It looks to be doing well.

Since, I was back in the hammer compartment, flattened and polished the hammer tension spring,
cleaned the hammer housing and very lightly re-lubricated with spring chamber oil.

Then I got to thinking about the position of the damping grommet.
Experimented on a similar compression spring by clamping one end and striking the other end to check how noise is produced.
Then, I added a dampening grommet and slid it to various positions to find where it did the best job.
Of course, it turned out the middle of the spring dampens noise the most.
Yep, right where the cocking spring would interfere.

So I’ve followed the lead of another forum member and lifted the anchor point of the compression spring to clear the grommet

Used a longer M3 bolt and a rubber spacer to lift the spring attachment point.

Once back in place and with grommet placed at most effective, centered damping position.

The cocking spring just clears the grommet

Now back to shooting. It’s quiet enough for me shooting indoors.

Good Job, benj397

I really like your L bar to make the perfect line.

I never removed the rearmost baffle. You went a step further.
I don’t have a delrin spring guide, but instead covered the brass bushing with the rubber seal of a 10 ml BD syringe.
My concept of an idea delrin spring guide would have a bigger shoulder with a recess for an o-ring to absorb the impact.
That would last for a long time.

Meanwhile I just will keep an eye on things.

There was mention in an early thread of a spacer associated with the regulator that could be the source of the firing ping.
That firing ping is the loudest part of my gun now.

quote :

Here is what Ernest wrote:

(Finally found the ping sound after the shot, its the reg and firing valve spacer–since the reg has no back stop like the cricket, edgun so you can push the reg out the other end—so that spacer can be loose so what I did was added a thin oring on the reg side and added a electrical tap around the spacer, so the key point for the other owners is to use the firing valve to push the reg and spacer into position, if not you can over shoot the vent hole for the reg.)

Sounds like really all he did was put, added a electrical tape around the spacer, added a thin oring on the reg side.
push three parts back in.

It still a bit much for me to tackle, but once I learn more, it’s on the fix list
Maybe take the entire air cylinder apart?
The SniperQTY video shows him pulling the regulator out from the front of the air tube after removing the pressure gauge, but that’s still
on the wrong end of the tube.

EDIT: added info about the rubber cap for brass bushing

The rubber piston seal of a 10 ml Becton Dickson syringe is just the right size to cover the brass bushing.

Pull the piston out of the syringe and pop off the black rubber seal.
Notice the shape of the plastic piston end? It is just like the flange of the brass bushing.

This is the rubber seal. It has a molded recess into which the brass bushing’s flange will fit.

Leather punch a hole in the center of the cap just a little smaller than the hammer shaft.
Once you stretch the cap over the bushing flange, the hole will be a bit bigger.
Make sure the hammer can slide easily through your hole.

Of course, orient the cap so it is in front of the bushing (the side away from the spring).

Now the rubber cap takes the hit instead of a direct metal metal impact.

I don’t know yet how long the cap lasts, but it will be easy to replace when worn out. (EDIT 500 rounds and still OK)

NB: you probably will only have room to fit ONE grommet on the hammer spring if you add this cap.
Two grommets and the assembly is hard to fit back into position.

Well, I ordered the Lisle 30280 Automatic Center Punch and a couple 1mm drill bits. I got all of it yesterday.

Wow, I should have had the automatic center punch in my tool chest long ago. These things are great!!

Well, I performed the mod this morning. I hand twisted the shroud and it came loose. So I hand tightened it back, put a piece of painter’s tape around the shroud at the front end above the air tube. This allowed me to pencil mark the very bottom of the shroud so I could use that mark for my “line” down the shroud. That way, I didn’t need to shim with an o-ring. Just tighten it back up.

After removing the shroud, I did like everyone else and covered it with painters tape to protect the finish. Don’t forget to remove the 2 little allen screws holding the last baffle before wrapping or you will be hunting for them under the tape. Don’t ask :whistle:

Anyway, I had a pice of 1/2 angle aluminum. By setting the shroud into the channel, and lining up the leg of the ‘L” with the previously made mark on the end of the shroud, you can mark a straight line all the way down the shroud.

Then I measured and marked for the holes and then drilled them. The “all thread” to remove the burrs works very well. Getting the baffle back in the right place that takes the allen screws was a small challenge. I put the baffle on top of the shroud with the hole for the allen screw in line with the allen hole in the shroud. I then took a long screwdriver and put it at the forward end of the baffle and measured out to the end of the shroud. I put a piece of tape on the screwdriver at that mark. I then put the baffle into the end of the shroud lining up the allen hole with the hole in the shroud so it would be correct once the baffle was slid down the shroud. Then I used the screwdriver and pushed until I got to the tape.

I did this on my 22 vulcan. The muzzle report is less I think. I’m holding the gun off to the side while firing in a safe direction. Arms length from my ear. I also have the delrin guide from Ernest and put the 1 o-ring mod on the hammer spring. The hammer slap now is the loudest part of the gun.

Thanks for everyone’s testing and posting about these mods.

I’ll just quote Hoot to answer why…..

quote :

I’m making this as simple as I know how!

There is only ONE way to quiet a pcp. You must reduce the air pressure exiting the muzzle. How? There are only two physically possible ways. One is to disrupt the air flow with baffles and cause it to leave the muzzle in a long column instead of one short hard blast. The second method is to physically reduce the amount of air the baffles must deal with, and that is to vent the air to the outside before it hits the muzzle. That’s it. No genius involved…just a simple look at the physics of the problem. Now, I will tell you how…

1) Vulcan baffles have a tiny O ring at the top and bottom of each baffle…and I’m not talking about the big O ring between each baffle. That’s right…look for yourself. Since each baffle has two holes in it, air is released into that small dead air space between those two tiny O rings and the shroud tube. It works. Want to make it work better, say MUCH better? Carefully measure where the middle of each baffle will be, when in place, and drill a small hole into each side of the shroud where the middle of each baffle rests, so that trapped air between those two tiny O rings can escape to the outside. The hole should not be larger than 1/16th inch. You can go larger…slightly. AND, put one on each side of the shroud. NO…the holes in the baffle sides do not have to line up with the tiny shroud vent holes. The air doesn’t care where those holes are located. It will find its way out just fine. That way, each successive baffle has less air pressure to deal with.

Note these tiny baffle O rings, and you have to look close to see them, prevent gross baffle metal to shroud metal contact, and what little metal contact that does take place is muffled by the large O rings between each baffle. That’s one big difference I saw in the TGAG baffles and the OEM baffles.

2) Now the simple part. You have vented each baffle at the muzzle end of the shroud and that reduces air volume, pressure, vibration, and prolongs the exhaust time of the muzzle blast…that alone quiets the gun down. BUT…you need more, much more. You can do as I have preached again and again…put eight (8) holes at the base of the shroud, about an inch to an inch and one-half up from the breech. You can put them in a circle around the shroud, or you can put them in a straight line at the bottom of the shroud. How do you keep the shroud from rotating and showing those eight holes at the bottom in a straight line? Easy…buy an O ring slightly smaller than the shroud and put it over the barrel so the shroud compresses it against the breech when you screw the shroud on. The forward pressure of that compressed O ring will hold that shroud in place quite nicely, and those holes stay out of sight.

This being done, you have reduced air volume/pressure exiting the muzzle at 16 to 20 points along the shroud length, depending on how many holes you use. (I only did four along each side of the shroud, along side each baffle. I skipped venting one baffle…looks better. )

Now, if you need Really Quiet, buy a DonnyFL LDC for the front of your shroud. John Hagan makes an adapter for Vulcan shrouds.

At this point I defy you to make the Vulcan .25 any quieter without lowering FPS. I run mine at 50 FPE because that’s what I want out of a .25 caliber! Do this to a Vulcan .22 and you could shoot the damn thing next to your sleeping wife and not wake her up!

Why 13 holes? And why put some up front and some in back?

Anyone else do this mod?

quote Beach-gunner:

eelect,
Perhaps you should avoid Ville’s bar before you go out to shoot your gun, this will enable you to remember that you have engaged the ROT :rofl: :4:

No booze for me, just one here and there. Don’t want to ruin a perfectly functioning brain. I have gotten better at not forgetting to turn off the rotation switch. What helps is to switch it off right after you load pellet.

eelect,
Perhaps you should avoid Ville’s bar before you go out to shoot your gun, this will enable you to remember that you have engaged the ROT :rofl: :4:

The rotation lock makes me dry fire the next round about 9 times out of 10.

Sent from my Z30 using Tapatalk

It’s easy to decoct, by holding the bolt back and pulling the trigger.
The only gotcha is you also need to avoid double loading on the next time you cock and advance the bolt.
That’s when the ROT stop is useful.

look de cock it then, or is there any problem with decocking this gun

I think this is a matter of habit…

having said that I am using it currently as a single shot hehehe

Couldn’t stand the difficult to manipulate safety any more.
Needing to reach into the trigger guard with my thumb to get enough pressure to break the safety free was worrisome.
It was all too easy to accidentally engage the trigger with my thumb while struggling to release the safety.

30 minutes careful scraping with a diamond file on the safety plate (where it engages the trigger blade) thinned the plate down to engage with less resistance.
Then, some work with a narrow strip of 800 wet-or-dry got it down a bit more.
By lightly clamping the strip of 800 between the trigger blade and safety plate and pulling the the strip, I could let the pieces guide where the sanding occurred.
Just clamp super light and drag the strip to remove metal strategically.
I took care to avoid grinding the trigger blade itself.

Removed just enough metal to do make the safety engage with low force, but still disengage with a definite, small resistance.
Moly grease and maybe a hundred engage/disengage cycles has the safety working as I want.

I can now flick the safety on/off with just my trigger finger – definitely far better than the mal-functioning state it arrived and more conducive to use than when it was super stiff.
An added benefit is that now I can adjust trigger pull resistance without affecting whether the safety functions.

I tried several combinations of 2 different OD and thickness 3/8″ID grommets but was only checking for noise However I did notice having to turn in the HST more for 2 setups that both reduced the length of the twang.

I did verify that with 18.1 JSBs I got better chrono SDs when tuned up from 890 fps to 910 fps.
Changed from 4.0 to 1.7 for 11 rounds.

Mine stayed the same with and without them.

Have chrony numbers before and after the grommets?

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