What is the best way to depressurise am Air Arms PCP?

[Duckfish]

Just shoot it down?

[96720]

Yes, as far as I know.

[Motorhead]

Partially unscrew pressure gauge block hold down screw, o-ring will pop free and tank will empty.

[scrane]

Partially unscrew pressure gauge block hold down screw, o-ring will pop free and tank will empty.

Can you damage an AA 4xx/5xx valve or hammer by dry firing til it dumps?

[Rdsail]

I have shot down my MPR S400 about 50 times or more.  I'm not exaggerating the amount. This requires about 80 shots if the gun is full. I have never had and issue with the valve, poppet or hammer.

The method of unscrewing the guage works but you can easily damage the tiny oring. Which if I remember currently is a 7x1 mm. Might be 6x1.

[Norm_m]

X2 to Scott's way as I have done that several times. May be a good idea to have some extra O rings just incase you damage one, I never have

Shooting it down works fine but if you have a reg and a tune of 12 FPE it can be well over 100 shots!!!

Norm

[Duckfish]

Shooting it down worked great.  And when it got to about 50 bar it emptied thru the barrel.  My new custom pistol from TOPGUN Airguns isn't shooting up to snuff.  Advertised as 11 foot pounds it is shooting 3 foot pounds with 8.4s.  Back to Petr it goes.   Hope he can get it fixed before Concord FT starts back up.


Duck

[Jking]

Here's the tool I made that really comes in handy if your going to be bleeding down the air tube (S4**, S5**'s)more than occasionally. This idea was on another thread so I just copied it using different material. I used a piece of 1/2"emt electrical tubing which I believe is 2.10"long. I had to ream out one end a little so that it can slide over the hammer. If you have dismantled it and have the just hammer setting on the guide, put this too the guide and onto the hammer , add a washer with a small hole so that the hex screw has something to push against. Slowly tighten the screw which in turn forces the valve open and lets the air exit through the barrel nice and slowly. Found that while regulating my S510 Carbine it came in very handy.
jimmy

[needmoretoys]

I have shot down my MPR S400 about 50 times or more.  I'm not exaggerating the amount. This requires about 80 shots if the gun is full. I have never had and issue with the valve, poppet or hammer.

The method of unscrewing the guage works but you can easily damage the tiny oring. Which if I remember currently is a 7x1 mm. Might be 6x1.

I wonder why the Air Arms user manual and Pyramyd Air tech support both say not to dry fire the S400 without a pellet in the barrel. It says nothing about having air pressure or not. I just want to be able to set up the trigger to my liking when my new S400 MPR Precision arrives. I would only dry fire it with over 1000 psi in the cylinder. The quote from the AA manual is:

"Do not shoot without a pellet in the chamber (dry fire). This may permanently damage your air rifle."

[Rdsail]

I have no idea.  I have had the gun fully apart. I don't see anything that would get damaged. The poppet I spring is long and the hammer energy is not enough to push the poppet spring to binding when fired without pressure. If the poppet would hit at the end of the travel, I could see it getting dammaged.

Also, I'm referring to the MPR ft,  I don't know if this applies to the other versions which are a little different.

I was able to adjust my trigger to 3.5 onces. Love it!

[Avra]

I have shot down my MPR S400 about 50 times or more.  I'm not exaggerating the amount. This requires about 80 shots if the gun is full. I have never had and issue with the valve, poppet or hammer.

The method of unscrewing the guage works but you can easily damage the tiny oring. Which if I remember currently is a 7x1 mm. Might be 6x1.

I wonder why the Air Arms user manual and Pyramyd Air tech support both say not to dry fire the S400 without a pellet in the barrel. It says nothing about having air pressure or not. I just want to be able to set up the trigger to my liking when my new S400 MPR Precision arrives. I would only dry fire it with over 1000 psi in the cylinder. The quote from the AA manual is:

"Do not shoot without a pellet in the chamber (dry fire). This may permanently damage your air rifle."

Never had a problem depressurising / dry firing my s-510 and I don't think that dry firing it would cause any damage either!
I have done it in very many occasions in the past few years.Same with my friends' s-400 & s-410.I don't know why in that AA manual it is suggested NOT to do it since in my AA manual it is suggested the exact opposite! Maybe that particular paragraph  was coppied by mistake from the springer AA manuals?Just my 2c...

[Smoketown]

The Air Arms website explains and demos ways to degas their rifles in the DIY section.

It's also on Youtube 

Cheers,
Smoketown

[Ginuwine]

The Air Arms website explains and demos ways to degas their rifles in the DIY section.

It's also on Youtube 

Cheers,
Smoketown

Was going to ask for the link, but i saw a video by Matt Dubber at the air arms factory where they broke the cylinder loss and then let the air bleed out.   Will have to replace o-ring but that was most likely the plan anyway.

[cilami]

This is how RAW website recommends to empty the AA.  I did and it worked as described. Easy and fast.

http://www.rapidairweapons.com/xcart/files/pdf%20files/Air%20Arms%20Male%20Coupling.pdf

[needmoretoys]

I downloaded the user manuals for the S400, S410, s500 and S510 series and the FTP 900 from Pyramyd Air and they all have that same warning in them. However, none of the ones that I downloaded from the AA site have that warning. The manuals from the PA site are printed by Air Venturi, the importer for AA in the USA. Perhaps the AV lawyers wrote them.