Tuning Tune a Maximus for power?

[TC724]

I purchased a Maximus a couple years ago for tinkering purposes and now I want to tune it for higher energy levels.

Currently shooting it stock with 24ftlbs and getting 15 great shots and 20 useable shots per fill from 2000-1200. Using 15.89 JSB pellets and getting excellent accuracy.

I actually have a hammer spring adjuster I got from magnum air power and a light spring I used to detune the gun to 13ftlbs. As I said I bought this to mess with a bit.

I’d love to get like 10+ shots a fill at 30ftlbs or more but I’m not willing to get less than 10 shots per fill. So my main question is can that be done easily or will I need to do more than just play with the hammer spring tension and fill pressures?

I don’t care if I shoot pellets or slugs but I just want to know from the people that have done this already what it’s capable of. Just looking for insight or what you might of done to get there!

 

[SilentSquirrel]

Following with great interest

 

[otis1016]

I have the Maximus I got a couple years ago and have done almost nothing to it. No need, I don’t hunt with it, just target and plinking. I can get 10-15 shots between fills easily enough. With a red dot it’s accurate to 50 yards easily. Probably about to live under the backseat of my truck next to a powder gun. I actually get what I want from it with factory setting.

Rick H.

 

[SilentSquirrel]

TC724
Have you read MagnumAirPower's info regarding what he accomplished with a Discovery & a Maximus barrel?
His valve screws allow filling to 3K
Here is the link

CUSTOM DISCOVERY VALVE SCREWS for 3000 PSI

CUSTOM BENJAMIN DISCOVERY VALVE SCREWS for 3000 PSI

onlinestore.magnumairpower.com

In your situation it would be a Maximus with a Discovery tube

I have not tried this yet
However, it's on the list; and I have all the parts

Hope this helps

Ed

 

[TC724]

I have the Maximus I got a couple years ago and have done almost nothing to it. No need, I don’t hunt with it, just target and plinking. I can get 10-15 shots between fills easily enough. With a red dot it’s accurate to 50 yards easily. Probably about to live under the backseat of my truck next to a powder gun. I actually get what I want from it with factory setting.

Rick H.

I agree the factory setting is great I just wanted to try to squeeze more power out for the sake of playing with it. I’ve owned a lot of pcp rifles but never played with them much lol

 

[TC724]

TC724
Have you read MagnumAirPower's info regarding what he accomplished with a Discovery & a Maximus barrel?
His valve screws allow filling to 3K
Here is the link

CUSTOM DISCOVERY VALVE SCREWS for 3000 PSI

CUSTOM BENJAMIN DISCOVERY VALVE SCREWS for 3000 PSI

onlinestore.magnumairpower.com

In your situation it would be a Maximus with a Discovery tube

I have not tried this yet
However, it's on the list; and I have all the parts

Hope this helps

Ed

I’ll take a look at this Ed thank you. I figure even if I just adjust the stock hammer spring I may be able to squeeze the 30ftlbs out of it but just not very long without messing the valve.

 

[SilentSquirrel]

I’ll take a look at this Ed thank you. I figure even if I just adjust the stock hammer spring I may be able to squeeze the 30ftlbs out of it but just not very long without messing the valve.

Be aware of hammer spring adjustment.
The tighter it gets the harder cocking will become, putting greater stress on the bolt handle
Make sure it is screwed in all the way.
Even then, it is prone to bending or breaking.

Ask me how I know

Ed

 

[TC724]

I’ll take a look at this Ed thank you. I figure even if I just adjust the stock hammer spring I may be able to squeeze the 30ftlbs out of it but just not very long without messing the valve.

Be aware of hammer spring adjustment.
The tighter it gets the harder cocking will become, putting greater stress on the bolt handle
Make sure it is screwed in all the way.
Even then, it is prone to bending or breaking.

Ask me how I know

Ed

Lol I appreciate the heads up. I will take it slow, if anything maybe I can improve the stock tune if all else fails.

 

[airgunner53]

Any update on your tune?

 

[TC724]

Unfortunately I was never able to achieve what I wanted power wise even shooting some fairly heavy pellets. I ended up selling the Maximus to someone on the forum shortly after. It’s possible to get more power but don’t think by just messing with the hammer spring

 

[xsarfc9x]

I got a MAP valve, larger TP and heavier hammer spring on my 2260 based gun and I get 6 usable shots at about 28fpe from a 2500psi fill. using heavier pellets. More work than the original poster had wanted to do but they’re easy to work on. I could go with a longer barrel but I like the compact size.

 

[airgunner53]

I got a MAP valve, larger TP and heavier hammer spring on my 2260 based gun and I get 6 usable shots at about 28fpe from a 2500psi fill. using heavier pellets. More work than the original poster had wanted to do but they’re easy to work on. I could go with a longer barrel but I like the compact size.

View attachment 409135

I have the same compact build in co2 and one in pcp with a multishot breech. Fun little carbines.

 

[airgunner53]

Just picked up a maximus and once I get a spare valve I will jump down the rabbit hole.
Does anyone know if with the upgraded screws and with a third one taped in if the maximus will hold 3kpsi.