How does my tune look like and any suggestion?

This area is dedicated to the .22 caliber Benjamin Marauder by Crosman.

Re: How does my tune look like and any suggestion?

Postby Mapuia » Wed Feb 25, 2015 9:47 am

That's an interesting little unit. Since you have to put the muzzle so close to the box your actual numbers may be a bit different than what you see here. Most guys here place their chronys 2-4 feet away from the muzzle. Whats important is the relationship from one shot to the next, and that's what this chrony will give you. It looks like it is made for airsoft guns, be sure it will detect velocities like those from your marauder before you get it.


Ray,
Youve mentioned that the numbers may differ in my UFC chronograph, which one will give me higher velocity? The chrono which they used here where they placed their chronys 2-3 feet away or my chrony which i put in the muzzle? I shot some string today with jsb 18.13gr today with settings of
Valve meter 3.5ccw
Hammer spring 6cw
Hammer strike 8cw
This settings give me max velocity Around 830 fps with 2600 psi fill, i was hoping i would be getting a higher fps
Mapuia
 
Posts: 28
Joined: Thu Jan 15, 2015 10:09 am

Re: How does my tune look like and any suggestion?

Postby RayK » Wed Feb 25, 2015 1:00 pm

Mapuia wrote:
That's an interesting little unit. Since you have to put the muzzle so close to the box your actual numbers may be a bit different than what you see here. Most guys here place their chronys 2-4 feet away from the muzzle. Whats important is the relationship from one shot to the next, and that's what this chrony will give you. It looks like it is made for airsoft guns, be sure it will detect velocities like those from your marauder before you get it.


Ray,
Youve mentioned that the numbers may differ in my UFC chronograph, which one will give me higher velocity? The chrono which they used here where they placed their chronys 2-3 feet away or my chrony which i put in the muzzle? I shot some string today with jsb 18.13gr today with settings of
Valve meter 3.5ccw
Hammer spring 6cw
Hammer strike 8cw
This settings give me max velocity Around 830 fps with 2600 psi fill, i was hoping i would be getting a higher fps


I think that was npunk42 who said that.

Open your velocity metering screw to max - 5.5 turns out CCW from fully CW. It just restricts the air flow which lowers your pellet velocity.

Ray
25 W-rod | 8 shots @ 70 FPE -2% | 3100 fill
25 M-rod | 40 shots @ 35 FPE -4% | 3100 fill
22 M-rod | 51 shots @ 25 FPE -4% | 3100 fill
17 M-rod | 60 shots @ 19 FPE -4% | 2500 fill
25 P_rod | 16 shots @ 28 FPE -4% | 2100 fill
RayK
 
Posts: 5371
Joined: Sat Jun 05, 2010 3:19 pm

Re: How does my tune look like and any suggestion?

Postby Mapuia » Wed Feb 25, 2015 6:03 pm

After i opened the valve meter 3.5ccw and pretension to 6cw pumping was easier than before when it was valve meter was 2.5ccw and pretension 4cw is this possible or is it just me?

And Ray, sorry for the wrong quote!
Mapuia
 
Posts: 28
Joined: Thu Jan 15, 2015 10:09 am

Re: How does my tune look like and any suggestion?

Postby Mapuia » Sat Feb 28, 2015 5:53 am

Ray,

I was tuning my rifle today with settings of Hammer spring 6 1/2 cw, stroke 8cw and VS 2.75ccw and yield 40 shot between 805-837-802fps with jsb 18.13gr with 2700-1600psi fill. I was quiet happy with what i was getting but after shooting it for a while i found out that the hammer stroke adjuster was moving. As i was turning the stroke adjuster to put back to the same 8cw from fully ccw i found that till 2 turns from fully ccw it was a bit stiff to turn till 2 turns cw (thinking if i left it here it will not move) afterwards it was moving easily, so if i leave the hammer stroke adjuster to 2cw from fully ccw and hammer spring to about 3 turns cw to maintain the fill pressure and prevent the bouncing which makes it burps and adjust the velocity using the valve metering screw. Will i still be able to achieve my 805-837-802 fps with the same efficiency and quietness?
Mapuia
 
Posts: 28
Joined: Thu Jan 15, 2015 10:09 am

Re: How does my tune look like and any suggestion?

Postby RayK » Sat Feb 28, 2015 9:21 am

Sure.

Yes, the settings will move unless you take steps to prevent them from moving.

The latest and easiest solution is to use vibratite vc-3. Loctite does not work because it does not allow changing settings after it cures.
http://www.amazon.com/Vibra-TITE-VC-3-Threadmate/dp/B008D6GHY6

Be sure to let it fully dry on the threads before you re-assemble your parts. Just a thin coat on the threads is all you need/want.


Ray
25 W-rod | 8 shots @ 70 FPE -2% | 3100 fill
25 M-rod | 40 shots @ 35 FPE -4% | 3100 fill
22 M-rod | 51 shots @ 25 FPE -4% | 3100 fill
17 M-rod | 60 shots @ 19 FPE -4% | 2500 fill
25 P_rod | 16 shots @ 28 FPE -4% | 2100 fill
RayK
 
Posts: 5371
Joined: Sat Jun 05, 2010 3:19 pm

Re: How does my tune look like and any suggestion?

Postby Mapuia » Sat Feb 28, 2015 9:35 am

I saw one post where they talk about factory set screw hammer stop for .22 marauder. Is this installed from factory? Im not sure what it actually is, can you expain what it is
Mapuia
 
Posts: 28
Joined: Thu Jan 15, 2015 10:09 am

Re: How does my tune look like and any suggestion?

Postby RayK » Mon Mar 02, 2015 7:15 pm

Early Gen I M-rod rifles had a set screw in the front hole of the hammer for the striker to help hold the striker setting from moving as you shoot.

It was great!

But Crosman decided to eliminate it, so they have not been made that way for around 4 or 5 years. Some have added their own. I added one to my earlier P-rod, but I don't bother any more. Vibratite VC-3 works well and is so much easier.

Ray
25 W-rod | 8 shots @ 70 FPE -2% | 3100 fill
25 M-rod | 40 shots @ 35 FPE -4% | 3100 fill
22 M-rod | 51 shots @ 25 FPE -4% | 3100 fill
17 M-rod | 60 shots @ 19 FPE -4% | 2500 fill
25 P_rod | 16 shots @ 28 FPE -4% | 2100 fill
RayK
 
Posts: 5371
Joined: Sat Jun 05, 2010 3:19 pm

Re: How does my tune look like and any suggestion?

Postby Mapuia » Tue Mar 03, 2015 2:44 am

thanks again for your reply.
Im thinking of moving up with the bstaley tune, does this tune alone increase efficiency?
Mapuia
 
Posts: 28
Joined: Thu Jan 15, 2015 10:09 am

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