Benjamin trail np2

[smellslikepeople]

So I have been noticing a velocity loss in my trail np2. The cocking effort has not decreased and I replaced the breech seal. So I ordered a new vortek seal for it. This will be my first time doing this so any helpful tips will be appreciated like what lube to use preferably one I can get at the store. Where to sand any and all tips tia

[mobilehomer]

Sand and smooth ALL rough surfaces. Tube and linkage. Search "piston seal replacement" here, there are many good methods. As to the lube, the best are Krytox/Ultimox or moly paste. None of which are available locally for most people. Either is available from Amazon. I prefer Krytox/Ultimox. It is more slick and clean.
Now for a small bit of tuning help. While you have the piston out(not necessary to remove the barrel to do this), loosen the lock set screw in the front of the left fork. Then loosen the pivot bolt just a little. Then break the barrel. With the tube pointed skyward, let the barrel hang loose. You want to tighten the pivot until it just barely holds the barrel in position. This will lessen the cocking force by almost half. It comes way too tight from the factory.

[smellslikepeople]

Since I'm using their moly seal it says there is no need to lube it. Is this true

[DanD]

Since I'm using their moly seal it says there is no need to lube it. Is this true

You will still want to lube the metal to metal contact areas like the piston skirt, cocking slot area,  etc.

[Roadworthy]

You should be especially concerned with the cocking slot.  It is frequently razor sharp near the inside edges.  These edges can slice a seal on installation.  A flat file works really welll for smoothing them off.  The same goes for any other sharp edges you find.
By the way, I strongly recommend a spring compressor for the disassembly.

[smellslikepeople]

How would I go about building one. I was thinking using a 18 inch Bar clamp and securing it to a piece of wood with a v cut into it. Would this work?  I ordered the air Ventura moly paste. Is that a good one?

[smellslikepeople]

Also it may seem like a dumb question but I want to ask it in advance. How will I know which way the new seal goes on. Can someone explain like groove facing barrel when assembled ?  It may be obvious once I get it but want to be 100 percent ready

[Roadworthy]

For a gas strut powered gun (NP or NP2) I find a bar clamp with a jack screw is adequate.  There is less than a half inch of preload so a lot of jack screw travel is not required.  I got a 48" aluminum clamp from Harbor Freight for the purpose as I prefer to dismantle my guns without removing the barrel.  I have also constructed a regular spring compressor, also four feet long, for my conventionally sprung guns.
As far as the seal goes, the flat side goes toward the piston.  Look carefully at your old seal before you remove it.  I strongly recommend removing and reinstalling the old seal a few times.  This way you won't ruin your new seal.
Beware - if you ordered a Vortek moly seal they are MUCH harder than your original seal.  A different technique may be required for installation.

[1mtnMike]

So I have been noticing a velocity loss in my trail np2.

Quadruple-F shout out! (F.F.F.F) "if you have to explain it",...right. 4x is already taken?!

Just curious, how did you know you were losing power?

[smellslikepeople]

I was shooting and everything was going fine then the groups opened way up and were shooting way way low.  So I shot a piece of plywood a few times and they would just bounce off back at me  then I shot a 2x4 and the pellet just made a dent in it wouldn't even stick in.

[smellslikepeople]

Lol. The fe fi fo fum is going to be what I'm associated with. But I'm cool with that