GTA

All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: knighted1 on October 10, 2016, 10:46:38 AM

Title: Marauder tune
Post by: knighted1 on October 10, 2016, 10:46:38 AM
Has anyone had any success with tuning their Marauder gen 2 in .25 caliber so as to deliver a heavy pellet in the mid to upper 900 fps velocities and still keep the rifle very, very accurate? If so what mods have you undertaken and what pellet selections?
Title: Re: Marauder tune
Post by: ezman604 on October 10, 2016, 10:56:43 AM
Gen I should be basically the same, I've not opened up a Gen II yet. Will soon.
But to get more power to push a heavier pellet will involve some valve work. Like opening the inlet side of the valve, necking the poppet, opening the transfer port and adding a lighter poppet spring. Then add a light weight hammer with internal SSG. Breech and barrel transfer ports will have to be opened to match the valve and new transfer port tube made. I have one that likes JSB 33.95gr Diabolo ammo and pushes them around 65fpe and very accurately.
SAFE & Happy Shooting!!!!
Dave
 8)
Title: Re: Marauder tune
Post by: hanleyfan on October 10, 2016, 12:54:27 PM
I bought a war valve and no bounce hammer and got my marauder 25 cal. pushing 996 fps but the accuracy was all over the place, I started dropping the velocity until I regained the accuracy and found 935 fps was about as fast I could push the 31 gr. pellet and still have the accuracy I wanted.  I don't know if all marauders are the same but with my gun 935 is the best I could pushed the pellet and still keep my accuracy.
Title: Re: Marauder tune
Post by: ezman604 on October 10, 2016, 12:58:21 PM
Try some heavier pellets.
Title: Re: Marauder tune
Post by: knighted1 on October 10, 2016, 02:51:27 PM
All great responses. How do I do all that Dave.  Wow very technical!!
Title: Re: Marauder tune
Post by: ezman604 on October 10, 2016, 02:59:54 PM
Yep, it's technical. :)
If you don't have or have access to a lathe, mill and/or a good drill press, I would suggest you send it off to have it done.
Several I would recommend are Scott (Motorhead), David (Rocker1) and Travis of W.A.R. (oldpro). I enjoy doing these things WHEN I can find the time. But I'm not taking in any to do simply because I can't guarantee when I could get to it. And I don't like working like that.
Title: Re: Marauder tune
Post by: knighted1 on October 10, 2016, 06:32:36 PM
Ok thanks for the info
Title: Re: Marauder tune
Post by: LDP on October 10, 2016, 09:42:17 PM
This is a mod im gonna do to my Mrod when shooting seasons over. I want to push 34 gr. JSB somewhere between 850 - 900 fps. Does anyone have a good link detailing the valve work?
Title: Re: Marauder tune
Post by: ackuric on October 13, 2016, 02:21:25 PM
Am interested in the same, would love to buy a spare valve and send it off to someone to get ported. If anyone can provide this service let me know!! :)
Title: Re: Marauder tune
Post by: n2omike on October 13, 2016, 09:20:53 PM
Am interested in the same, would love to buy a spare valve and send it off to someone to get ported. If anyone can provide this service let me know!! :)

You can buy aftermarket valves.  WAR (Wicked Air Rifles/oldpro on here)  sells an awesome valve.  You can also buy nice valves from hillairgun.  No core required.