Maximus upgrades

[bowdoc64]

Placed my order with Magnum airgun. I can't wait to get my parts. Great guy  to deal with. Answerd all my questions with quick and detailed answers.

Parts that are  on the way

Marader stem
Ultra light Maximus valve spring
Upgraded 2400 psi valve screws
Magmun hammer spring.

[Doug Wall]

Which hammer spring did you order? If it's the 0.045 wire spring, it's about the same as the OEM spring. I much prefer the 0.042 spring, as it's much easier cocking (reports of bolt handles breaking off!), gives a better shot count, and a better velocity curve.

[bowdoc64]

Which hammer spring did you order? If it's the 0.045 wire spring, it's about the same as the OEM spring. I much prefer the 0.042 spring, as it's much easier cocking (reports of bolt handles breaking off!), gives a better shot count, and a better velocity curve.

I have an aftermarket bolt handle. Stock one did not last a month with no mods. I have a homemade power adjuster now and have had zero problems with the new bolt handle. I'm going to be running 2400 psi and use the .45 wire spring without a power adjuster.

[bowdoc64]

I should get over 30 ft/lb with 20 shots. My current set u stock gun with homemade power adjuster gives me 13 shots

[bowdoc64]

Parts will  be in tomorrow..

Should have it up and running by Tuesday.

I had ordered a larger transfer port before I got the other parts.. I think I will try The gun with the new port then switch back to the stock one.. I have heard the gun will be more consistent with the stock port

[longhunter]

I cut 2 1/2 coils off the stock spring, made a power adjuster. The stock port is giving me 30 shots from 2000 down to 1250, with a 10-11 fps spread starting at 814, high of 824/ 825, finishing at 815.  Most shots are around 819 to 821. That's with the 14.3 crosman hollow points.

[rong1966]

I cut 2 1/2 coils off the stock spring, made a power adjuster. The stock port is giving me 30 shots from 2000 down to 1250, with a 10-11 fps spread starting at 814, high of 824/ 825, finishing at 815.  Most shots are around 819 to 821. That's with the 14.3 crosman hollow points.

Is the .22 Maximus more efficient than the .177, because I installed the .043 hammer spring in my .177 and I only get 16-18 shots within a 4% ES from about 1700 psi to 1100.  What is the best way to increase shot count?

[Dbez1]

Don’t know if it’s helpful, but I got a lighter spring from DiscosRUs and it’s much easier to cock.  Just to eliminate any future problems, I also got a SS bolt handle. Mine is in .22 and I get 30+ good shots but I only fill to about 1800 psi and shoot down to about 1000. Above that and accuracy suffers. I don’t have a chronograph so I can’t give you more information but my Maximus is surprisingly accurate out to 60-75 yards with CHP’’s and no wind.  It’s not a powerhouse though. One other thing is that I bought it used with an Mrod trigger which is very light.  I wouldn’t hesitate to take squirrel out to 30 yards. Your 16-18 shots doesn’t sound right to me but there are many others on here that are much more knowledgeable. Best wishes.

[bowdoc64]

Don’t know if it’s helpful, but I got a lighter spring from DiscosRUs and it’s much easier to cock.  Just to eliminate any future problems, I also got a SS bolt handle. Mine is in .22 and I get 30-40 good shots but I only fill to about 1800 psi and shoot down to about 1000. Above that and accuracy suffers. I don’t have a chronograph so I can’t give you more information but my Maximus is surprisingly accurate out to 60-75 yards with CHP’’s.  Not a powerhouse though. One other thing is that I bought it used with an Mrod trigger which is very light.  I wouldn’t hesitate to take squirrel out to 30 yards. Your 16-18 shots doesn’t sound right time but there are many others that have more knowledge than me.

I have a power adjuster that is maxed out.. before that I got 20 to 30 shots.

[longhunter]

I cut 2 1/2 coils off the stock spring, made a power adjuster. The stock port is giving me 30 shots from 2000 down to 1250, with a 10-11 fps spread starting at 814, high of 824/ 825, finishing at 815.  Most shots are around 819 to 821. That's with the 14.3 crosman hollow points.

Is the .22 Maximus more efficient than the .177, because I installed the .043 hammer spring in my .177 and I only get 16-18 shots within a 4% ES from about 1700 psi to 1100.  What is the best way to increase shot count?

The 177 should be more efficient. It all depends on tune, and velocity. Having a rear velocity adjuster is almost a must. Also, you don't want the hammer pushing against the valve stem, when the gun is in the uncocked position. If I recall, I have a gap of .005 between the hammer and valve stem.

[bowdoc64]

Don’t know if it’s helpful, but I got a lighter spring from DiscosRUs and it’s much easier to cock.  Just to eliminate any future problems, I also got a SS bolt handle. Mine is in .22 and I get 30+ good shots but I only fill to about 1800 psi and shoot down to about 1000. Above that and accuracy suffers. I don’t have a chronograph so I can’t give you more information but my Maximus is surprisingly accurate out to 60-75 yards with CHP’’s and no wind.  It’s not a powerhouse though. One other thing is that I bought it used with an Mrod trigger which is very light.  I wouldn’t hesitate to take squirrel out to 30 yards. Your 16-18 shots doesn’t sound right to me but there are many others on here that are much more knowledgeable. Best wishes.

Mine would shoot and still will shoot a quarter size 5 shot group at 50 yards. Sub quarter if you don't count the flyer.

[rong1966]

I cut 2 1/2 coils off the stock spring, made a power adjuster. The stock port is giving me 30 shots from 2000 down to 1250, with a 10-11 fps spread starting at 814, high of 824/ 825, finishing at 815.  Most shots are around 819 to 821. That's with the 14.3 crosman hollow points.

Is the .22 Maximus more efficient than the .177, because I installed the .043 hammer spring in my .177 and I only get 16-18 shots within a 4% ES from about 1700 psi to 1100.  What is the best way to increase shot count?

I may try a power adjuster to gain more shots.  Could I cut off some coils of my .043 spring or would it be better to get a new lighter spring to work with?

[longhunter]

A shorter, lighter spring and a power adjuster. Start low on preload and work your way up to your desired velocity.

[bowdoc64]

Magnum hammer spring top stock spring bottom.
The Magnum spring does not feel any stiffer then the factory spring. The Magnum spring is longer and the coils are spread out further then on the stock spring.. Gun cocks easier to me then when it was stock.. 

[bowdoc64]

Left is the ultra light valve spring right stock spring.. New spring is substantially lighter.. I can compress it with my fingers you cannot do that with the stock spring

[bowdoc64]

Left side new pin right side stock.. New pin is slightly smaller in diameter then the stock pin.

[bowdoc64]

Five shot 25 yards HN Hunter Extreem. First 3 looked like a 22 caliber hole

[bowdoc64]

First my Gun in stock had issues.. I took a good look at it because you here said something did not sound right.. My barrel port and sight nock are not cut right so my barrel port was not lined up right.. it's lined up now.

As for the magmun airpower parts. I easily get 20 good shots. The gun cocks easy with the Magnum spring. The more I shoot it the more accurate I think it is becoming like the parts are working there way in. I do not have a cronoy but I think the gun is shooting harder.  My HN extreemes shot a 22 Cal pellet hole for the first 3 and it was not much bigger for 5.. That's crazy accurate

[grand-galop]

Very good results with just minor adjustment...  That is what I like about the lower budjet gun.. They are easy to work on and the after market for them is tremendous.. A little help from the community and a little helbow grease could fix anything...    LOL

[Hoosier Daddy]

Great info here guys. Thanks for sharing.
Is it safe to assume the lighter .043 hammer spring would help my trigger as well as cocking effort?