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What to inspect in a used FWB P70 before paying ?

Posted: Mon Apr 28, 2014 11:28 am
by point177
I have been told by present owner that he is using it for seven years and the meter on the cylinder is not working. He claims its in good working condition.

What do I look for so I dont land myself a lemon. He is asking for a thousand US dollars.

Please advise.

Manish.

Posted: Tue Apr 29, 2014 9:30 am
by justadude
Manish,

It is hard to put together a specific list of check these 5 things and you will be OK.

If the cylinder is 7 years old, regardless of the manometer it is near the end of its life for competition purposes.

Trigger parts can become dusty/dirty affecting trigger performance and with the PCP guns the regulators need occasional attention to stay in top form.

You can often get an idea of how well a gun has been cared for by external appearance, does it look like it has been banged around or handled carefully? For finished surfaces are they bright or pitted and dingy? If externally the gun appears carefully handled and metal surfaces cared for then that is good and the rifle is probably worth the $1000.

Ideally the seller could provide a recent chrono test with velocities in the mid 500s ft/sec. I am not sure what the acceptable standard deviation is for the model P70 so I won't speculate there.

Perhaps the seller has had the rifle recently serviced, that would be a big plus. Although it does not sound like it.

Regardless, at 7 years, if you purchase the rifle, it would be a good idea so send the rifle to someone who services then (our sponsor for instance) and have it checked by an airgun smith. Like I say, the regulators are happiest with occasional attention.

Sorry if this is a little vague, but it will get you started.

Cheers,
'Dude

Bought it.

Posted: Wed Apr 30, 2014 4:38 am
by point177
I had a very small window of opportunity so travelled and checked that its working fine and bought it. The cylinder mamo meter is not working and is certainly old.

I am wondering how seriously should the word be taken on cylinder expiry date.
Not that I want to go against the grain but wondering if old ones need to be discarded or can be rebuilt.

Thanks for the advice as I am new to PCPs.

Manish.

Posted: Wed Apr 30, 2014 8:40 am
by justadude
The problem with and reason for the 10Y expiration date on cylinders is due to the very remote possibility of a type of corrosion, somewhat unique to aluminum setting in and weakening the cylinder from the inside out.

You need a combination of moisture and pressure to make this happen.

When filled with air that has not been properly dried there is the chance water could be introduced to the cylinder and hence corrosion could set in.

If a PCP cylinder were to rupture at 200 Bar pressure is would go off like a grenade.

After some debate, because it is not really practical to rebuild air cylinders, the ISSF picked 10Y as the lifespan of a cylinder.

Having said all that, for training purposes, many people run their air cylinder well past the 10year lifespan without any problems. If you get into competition and they are checking the born on dates then you will be stuck until you get a new cylinder.

I would be more concerned with the broken manometer. Makes air management a little tougher, unless you plan to fill prior to every training session.

'dude

Many thanks

Posted: Fri May 02, 2014 12:58 am
by point177
justadude

Many thanks for the reply. An investment in a new cylinder, moisture trap unit and 200 bar air tank is in order. Wondering if I will need a regulator.

Manish

Posted: Fri May 02, 2014 10:38 am
by TerryKuz
Moisture traps are pretty ineffective. I would suggest a scba tank if you can get fills. Scba has no water so the investment will save on maintenance in the long haul.

Posted: Sat May 03, 2014 1:03 pm
by point177
Thanks TerryKuz, noted. We do have folks who do fill SCBA tanks to 200 bar or more. I guess they ensure only dry air gets in the tank to be filled.

Manish
TerryKuz wrote:Moisture traps are pretty ineffective. I would suggest a scba tank if you can get fills. Scba has no water so the investment will save on maintenance in the long haul.

Here she is....

Posted: Sat May 03, 2014 1:04 pm
by point177
A picture of our FWB P70

Manish

Posted: Thu May 08, 2014 11:19 pm
by Peakconti
I have a styer LG100 my cylinder is over 10 years old, and my gauge does not work, I use hand pump, I only shoot a few air matches each year, although I do most of my practicing in late May till June. So my rifle is not heavily used. Not having the gauge is a pain, but a new cylinder cost a lot. I pump mine back up every other practice and prior to any match. Seems to work for me. However I am considering purchasing a new cylinder.