View Full Version : Velocity adjuster

03-10-2008, 07:16 PM
So again my neighbor let me borrow his Hammer and it is shooting at about 320. I can not see anywhere on it where to adjust the velocity and he is not around to show me. Does anyone know how. It is about 20-23 years old if that matters.

03-10-2008, 07:51 PM
Is there a screw inside the bolt?

03-10-2008, 08:55 PM
No. This has the simpelist inside i have ever seen. There is nothing inside the gun that is extra stuff, like a screw.

03-10-2008, 08:57 PM
You use an allen wrench down the front of the marker to the breech. TAKE OFF THE BARREL FIRST! If you don't have a long enough wrench, take off the pump arm and try again. It's a large sized wrench, I can't remember which, but it's big.

It's a Nelson based pump, much like the Traccer/Maverick, if my memory serves me right, so that should be how it's done. It'll only cock when air's in it, btw. Don't be surprised if it doesn't without. ;)

03-11-2008, 09:53 AM
If there isnt an adjustment inside the bolt you need an autococker or phantom spring kit to adjust the velocity.

03-11-2008, 11:44 AM
I used a cocker spring kit, with the heaviest valve spring and lightest hammer spring. I've also drilled a hole through the striker, but I guess that isn't an option if it isn't yours. That with a 13ci air tank gets me a very reliable 280-285 fps.

Edit: I suppose I should also list the prevailing theories behind springs:
Lighter main spring = less force on striker = valve open less = lower fps
heavier main spring = valve open less = lower fps
lighter striker = less force on valve = valve open less = lower fps.
The converse applies as well.

If you don't have a spring kit, you can always trim the springs down some, but a spring kit is the better way to do it.

03-14-2008, 07:27 PM
on otter's site he tells you how to adjust velocity. you should be able to take a flat-tipped screwdriver (or needle-nosed pliers) and screw the venturi clockwise (to raise velocity) or counterclockwise (to lower velocity). hope this helps!

03-26-2008, 11:19 AM
That works, if you have a venturi. My Hammer doesn't, and seeing as the OP said that his is probably 20-23 years old, his might not either. If that is the case, changing springs is the way to go.