Seeking more power from Benjamin Maximus

[crenne]

Please help me. I am 9 months into this passion and am looking to boost the power output from my Benjamin Maximus.

I have heard of people "shimming" these things, adding heavier hammer screws and pumping them up to higher PSI levels.

What should I actually do?

Thank you for your thoughts.

Chris

[farmerjoe99]

It depend exactly how much more power you are looking for and to what extent you are will and able to go?
Are you comfortable drilling and dremel'ing the valve or do you want to stick with just changing hammer springs etc?

How much power do you want?

The easiest way to start is to get a power adjuster aka preload adjuster, so you can adjust the hammer spring in and out
when tuning the rifle, do you have a chronograph for tuning?

[Doug Wall]

While you can power adjust/preload the hammer spring a little, it's already close to being coil bound as is, and if you preload too much, you won't be able to cock the gun. A heavier hammer spring might get you some, but it's already tough to cock with the OEM 0.045" spring. Charging to higher pressure isn't a safe option. I would say that if you want more than about 25 FPE, you should buy a different gun that's capable of going there

[nervoustrigger]

To get the biggest gains from a low pressure PCP like the Discovery, look into increasing flow through the valve, transfer port, and barrel port.

Next biggest thing would be to pin the valve to allow for a 3000psi fill.

It's one of the most modified platforms out there so you will have no problem finding DIY walkthroughs.

[crenne]

Thank you for the help. I have since found several threads that beat this topic to death.

Looks like the solution is a different gun based on my skill set and indifference to owning crony and dremels, etc.

[grand-galop]

The Maximus is such an easy Platform to work on, it`s easy to get lost in so many things to start with...  Start to DEFINE your needs and work your way up from there..

[KnifeMaker]

Thanks to Our very own "FarmerJoe", for (hammer spring adjuster and spring)
 And most welcome guidance from "Bob Restern", I am elated with my Maximus.

i was getting 760 fps with Jsb 18 gr pellets. Which was too loopy for my property and pest. Lighter pellets were not giving the accuracy I wanted.

Bob Rstern gave me the specs for the valve porting, TP porting and bbl. porting, and while I was at it, I milled the gauge block in an offset manner in order to not touch the gauge seating area. (Only milled 1/4" so far).

I reassembled the gun, and with the spring adjuster all the way out, (Weakest) it shot at 711 fps. It was in the 500's at the same settings before.

I then screwed the hammer spring adjuster from FarmerJoe (Discos-R-Us) all the way in, and backed it back out two turns to prevent coil bind, and was rewarded with 897 fps.,

ONe more turn in, and it went 942 fps. So back ;out it went to two turns out.

It went from a 23 fpe gun to a good flat shooting 30+ fpe gun.

Tim Hill of "Hill Airguns" supplied a De-pinger for the gun, and later, a spacer to increase area inside the D-Pinger. Similar to the penum for a Regulator. Thanks a Million Tim!!! It really Works!

She is dead silent now, (With the addition of The very efficient TKO LDC) And deadly on multiple pest at once now.   

The Baker trigger made for very good trigger control.
All in All, a very accurate, powerful, light weight walkabout AG!

I still maintain that my new Maximus can keep up with AG's selling for many, many times more money.

I will have to give it a good range session to see if it is as accurate at the higher numbers as  it was before.  It was a will under 1/4" shooter at 30 yards before all the mods. I feel that wind will cause more problems at the higher velocities than before.

 I will try and keep Her in the 880-890 fps range. 

Knife