Tuning Tuning Tips for the AEA MAX .457?

[BurntDog]

All the latest AEA HP series releases come with the power (washers) upgrade preinstalled.
Also a .454 round ball ammo even if it doesn't roll out air very well may allow air slip by the round giving you less power behind the ball guessing your grouping will suffer as well.

 

[Royal Scam]

So I have had the Max .457 a few days and a Hatsan hand pump...the pump seems to be doing it's job...air from nozzle/plug,gauge is moving..
Problem is that the gauge on the max is not moving.It goes down when shot and if I turn it to release air..once there was an air leak coming from the breach port itself...but seems slightly adjusting the plug,reinsertion solved...but still not moving gauge up.
I have greased the o rings on the plug,I have cocked it and tried to pump too.
I suppose I could release all the air and take the tank off but for what purpose? What would I look for?
A mouse in a parka? Jk..
But yea a little frustrated...and since we are on a tuning thread..what is the benefit of cutting springs at butt end on just a stock tank? Or does it just adjust maybe trigger weight?
Thanks.

 

[MrP]

I’m a little confused. Are you saying that tank came filled up from the factory and you’ve been using it but unable to pump any air back into the tank?

 

[Royal Scam]

I’m a little confused. Are you saying that tank came filled up from the factory and you’ve been using it but unable to pump any air back into the tank?

Yea that pretty much sums it up.

 

[MrP]

There is a tiny valve inside of the tank I believe it is called a check valve. This is the valve that allows air to pass-through from the pump but prevents the air from flowing backwards. I think but I’m not 100% certain that if that check valve is over tightened it may cause the situation that you have and it should be very easy for you to fix.

It entails degassing the gun, removing the tank (use care doing this step to prevent o ring damage - a slow twisting motion is the way), Unscrew the end of the tank to access the check valve. Then use an Allen key to loosen that valve a tad. If you over-loosen it you’ll end up with air leaking at the fill port.

To do any of this you will want to watch a couple of videos there are some on YouTube showing each of these steps.

You might also have the best result sending the gun back in for warranty repair in case someone gives you a hard time if you try to fix it.

My experience trying to deal with some of these issues with these guns was not good. For example on the two .357 max guns I tried (and returned both) the check valve did not have the hex nut shown in the videos but a flat head nut, very soft metal that I found impossible to adjust. I have a bottle adapter that does have the hexnut on the check valve and that one is easily adjustable I don’t know why they didn’t use that on the HP Maxx guns that I had.

 

[Royal Scam]

There is a tiny valve inside of the tank I believe it is called a check valve. This is the valve that allows air to pass-through from the pump but prevents the air from flowing backwards. I think but I’m not 100% certain that if that check valve is over tightened it may cause the situation that you have and it should be very easy for you to fix.

It entails degassing the gun, removing the tank (use care doing this step to prevent o ring damage - a slow twisting motion is the way), Unscrew the end of the tank to access the check valve. Then use an Allen key to loosen that valve a tad. If you over-loosen it you’ll end up with air leaking at the fill port.

To do any of this you will want to watch a couple of videos there are some on YouTube showing each of these steps.

You might also have the best result sending the gun back in for warranty repair in case someone gives you a hard time if you try to fix it.

My experience trying to deal with some of these issues with these guns was not good. For example on the two .357 max guns I tried (and returned both) the check valve did not have the hex nut shown in the videos but a flat head nut, very soft metal that I found impossible to adjust. I have a bottle adapter that does have the hexnut on the check valve and that one is easily adjustable I don’t know why they didn’t use that on the HP Maxx guns that I had.

Yea I should have just saved for something else.Just not a lot of options for .457 compact.
Thanks for the tips, soon as I can I will give this a go and let you know of success or failure.

 

[MrP]

It was the compact factor that got my attention as well. These could be so nice if they had a less picky fill valve and if the valve seat didn’t tend to fail. I wonder if they will release without the glitches or if they’ve already moved on.

Have been shooting the Rex p in .357 and it is a great gun, compact and powerful and theoretically available in .45. Seems to be the .50 cal is most common to find in stock.


Adjusting the valve:

 

[MrP]

One thing - have you pumped by hand before?

It takes a good number of pumps just to fill the fill whip, and only once the hose is up to pressure of the tank will the check valve pop open and air start moving into the tank. Also it tanks a lot of pumps to move the needle a visible amount on a 300 cc tank.

Apologies if you are an experienced airgunner and know all of this already.

 

[Royal Scam]

One thing - have you pumped by hand before?

It takes a good number of pumps just to fill the fill whip, and only once the hose is up to pressure of the tank will the check valve pop open and air start moving into the tank. Also it tanks a lot of pumps to move the needle a visible amount on a 300 cc tank.

Apologies if you are an experienced airgunner and know all of this already.

Seems I made it worse...took off the tank after releasing the pressure...needed a flat head here as well to make adjustments once inside...it was at an angle ..so I loosened it and re tightened just enough to make it straight up and down in there..just like that video you linked...I had been watching the very same...now it loses air everytime I pump....bad thing is I was not aware that I had to meet the same pressure shown on rifle gauge to the pump before the valve opens....I should have asked that first...live and learn. Could the rifle gauge itself be too tight or not tight enough?

 

[MrP]

Man, that’s a bummer. Wish I’d thought to ask how new you were first and focused on the simple issue. The angle of the screwhead doesn’t matter what matters is the tightness so what you will have to do is try a few different tightness levels. Eventually you will find a point where air goes the right m way and not the other but you can still pump it up. Not a fun process but if the part is not defective, you should be able to fix it.

 

[Royal Scam]

Man, that’s a bummer. Wish I’d thought to ask how new you were first and focused on the simple issue. The angle of the screwhead doesn’t matter what matters is the tightness so what you will have to do is try a few different tightness levels. Eventually you will find a point where air goes the right m way and not the other but you can still pump it up. Not a fun process but if the part is not defective, you should be able to fix it.

Yes these neumatic devices are pretty new to me..Nothing like ball and powder.
But yea I'm just going to keep troubleshooting until I find the sweet spot on that valve...shouldn't take to awful long...wonder how many pumps it will take before I buy a compressor,haha.
I appreciate you taking time to help bud.
Edit: seems now the leak is coming from the rifle gauge as opposed to the fill port...Maybe I tightened the gauge to much or not enough?...(just a slight tighten with channel locks).Or maybe a little plumbers tape?

 

[MrP]

Cock the gun before filling! This may be the issue. The hammer spring may be pushing the valve open.

 

[Royal Scam]

Cock the gun before filling! This may be the issue. The hammer spring may be pushing the valve open.

I had been curious of that too,not sure why I didn't ask.
So with gun uncocked I get a leak from fill prob port...with it cocked and the lever not pushed a slow leak from gauge on rifle...but now the hand pump gauge is no longer moving...
What fun! Seems I am getting closer to a solution here thanks in large to you.
I plan on getting better mags, I saw some horizontal 3d printed kind some where.Maybe I will look into a better gauge as well.
This thing is like a brand new "project" and that's ok ...good thing I enjoy learning new stuff.
Don't suppose safety switch makes a difference...bah nvm I'll figure it out.=)

Edit: Thanks to all your tips and advice ( and a little Teflon tape here and there) all is good and she is pumping up!!
Both gauges are reading properly and I hear no leaks!
Thanks again , MrP!!