• The AGN App is ready! Search "Airgun Nation" in your App store. To compliment this new tech we've assigned the "Threads" Feed & "Dark" Mode. To revert back click HERE.

Vulcan 3 Power/Velocity Loss?

Jump to latest Follow Reply
A

AdrianA

Member
Apr 8, 2022
5
0
CA, United States
Hey guys,

I am asking for some wisdom.

I got a Vulcan 3, I love it, it's the nicest gun I own.

First time out was shooting pellets at over 1000fps. Accurate, all great, put it in a case for 2 weeks. 
Next time out, shooting at 700fps, same pellets, same conditions, all looks fine, gun wasn't touched. Just lost about 300fps for no reason!?

This bothers me so much since it's a brand new gun! And not a cheap one.

Breach o-ring was suggested, that made sense, but I checked and o-ring looks fine.

Next suggestion was turning the hammer spring tension up. I will have to try this next time out, since I don't know what else to do.

But why would the spring loose tension, on a brand new gun? Is that normal? Doesn't seem normal to me on a high end gun.

Please help me with any thoughts and suggestions.

Thank you and and the best to you!
 
On my Vulcan 3 the hammer adjuster are extremely loose if the grub / set screw are not tightened, TBH i think as it come there are barely any pressure on the hammer spring, so i have no problem imagining that the damn thing could move.

I have also contemplated if i some how could make that adjuster "screw" have a tighter fit, even if it dont really matter much, cuz if you are in there to adjust the hammer the grub / set screw is also right there.

On my Maverick it is pretty much the same system, but here i have never touched the locking screw, but i have been all the way in and out in hammer adjustment several times and i am not worried anything will shift on its own.

Though ! When i have found a sweet spot for a slug i am going to give the lock screw a slight twist to ( i assume ) lock even better.
 
Upvote 0
After stock is removed the hammer spring is on the very back of the receiver. The allen set screw on top of the hammer spring housing is tighten to secure the HS setting. This may be loose but doubtful it would loosen up enough for you to loose 300 fps. Is it holding point of impact? If it is the chronograph may be the culprit. I also have a Vulcan 3 and have owned a Vulcan 2 for a year or so. I also am in the learning process. Good luck and if you are the original owner you're warranted for I think 3 years.
 
Upvote 0
Screenshot_20220409-132636.1649536044.png


This is upside down. Red is the grub screw that holds the hammer spring in place. The blue is the Hammer spring adjuster.
 
Upvote 0
After stock is removed the hammer spring is on the very back of the receiver. The allen set screw on top of the hammer spring housing is tighten to secure the HS setting. This may be loose but doubtful it would loosen up enough for you to loose 300 fps. Is it holding point of impact? If it is the chronograph may be the culprit. I also have a Vulcan 3 and have owned a Vulcan 2 for a year or so. I also am in the learning process. Good luck and if you are the original owner you're warranted for I think 3 years.
Click to expand...

Thank you for your help.

When I shot the gun the 2nd time, I noticed it was more quiet, but more important, point of impact was not even inside the 4" target, forget about the center, was 5-6" lower than where I zeroed it. That made me get out the chronograph, an FX, and surprise, it was shooting about 300fps less, and it explained the drop in point of impact.

But next time I get out I will try adjusting the hammer spring and see how that goes. 

 
Upvote 0
What I did on my vulcan 2 was to cut a peace of delrin, and put it on the bottom of that grub screw. Makes it easier when adjusting the gun, as you can have gradually friction on the adjuster screw. When it is metal on metal, it easy becomes totally locked, or loose. Find it usefull when adjusting the gun with stock on, as you do not have to lock it completely right after adjusting.
 
Upvote 0
AdrianA said:
Hey guys,

I am asking for some wisdom.

I got a Vulcan 3, I love it, it's the nicest gun I own.

First time out was shooting pellets at over 1000fps. Accurate, all great, put it in a case for 2 weeks.
Next time out, shooting at 700fps, same pellets, same conditions, all looks fine, gun wasn't touched. Just lost about 300fps for no reason!?

This bothers me so much since it's a brand new gun! And not a cheap one.

Breach o-ring was suggested, that made sense, but I checked and o-ring looks fine.

Next suggestion was turning the hammer spring tension up. I will have to try this next time out, since I don't know what else to do.

But why would the spring loose tension, on a brand new gun? Is that normal? Doesn't seem normal to me on a high end gun.

Please help me with any thoughts and suggestions.

Thank you and and the best to you!
Click to expand...
I'm having this exact problem. Have you resolved it yet?
 
Upvote 0
If it’s not the hammer spring, it may very well likely be that your regulator is creeping air into the plenum. Try shooting several rounds and see if velocities climb back to the original velocity range. If velocity does indeed return to the originally set range, then it’s regulator creep that is the issue in that the pressure in the plenum has become greater that the strinking force currently imparted by the spring is unable to open the valve as much as before.
 
Last edited:
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu