My Sl 68 II can no longer fire at velocity. I have tried a few tricks including installing a new cupseal set, full valve assy, springs and a better barrel. No matter what I have tried I cant get the velocity above 240 FPS. Today I took it over to tippmann and they put in a full new internal set and still its velocity was the same, They did a check and even with the velocity adjuster cranked all the way out it couldnt fire above 240. There are no occlusions that interfere with the hammer or bolt, the parts are well oiled too.

So my gun is kind of useless at this point.

I really dont want to sell it but I cant use it either.

Now I dont want to confuse anyone when I put up my second SL for sale as I have two. The malfunctioning one is my polished SL, The black one that I am going to list is shooting very well and is in the 298 FPS range and was just serviced this afternoon by tippmann as well.

That doesn't seem right. You've got all new guts and it's still no good?


Reball practice in the basement?

obstructed air passage?

Did you try swapping parts from the working gun?

clean or replace the hose from bottomline "adapter" and recheck. also try a remote line set up - I have seen worn pin depressors cause the same problem - acts like a bad reg
I'd bet it's wear on the pin depressor

Bob would it do this with various tanks old/new/HPA/Co2?

I will give it a shot though with a remote line and direct air. I have the funky vert air setup right now.

yes as it will only partially depress the valve pins on all of them. also remove the valve assy and blow tank pressure thru it - some smug in the line will act the same but I'm betting on the pin. remember that gun is at least a decade old if not older

The worn pin is a good bet......it could also let the face of the tank valve bottom out on the face of the ASA....obstructing the hole the air passes through.

Well I used an ASA extender, Swapped internals, blew the internal gas line out, used various tanks, made sure it was oiled at all times, Still I have a slow shooting gun.

Very frustrated.

Also I used a tank directly to the gun where as before I was going to an AGD vert mounted ASA.

The ASA extension should have made sure it was getting full pressure, same with swapping different tanks even using an on/off valved 3.5 Co2 tank.

HPA
Co2
Multiple tanks of each type, Used a full 88 ci 5k fill and blew out the internal line.

I think ive hit the end of the road for options. I wish I had a drill to follow the air passages with as thats the only item I can think of to try. Possibly side tapping the valve body to get air straight into the valve. I wont be doing that until a last ditch effort.

Take it all apart and soak it in some kind of parts cleaning solution for a day, then blow it all clean.
Also shim the spring as well.
Just cant let an old SL just die...
Did you polish the inside as well? Wonder if it has too much slack in it now?
With that much age, that could be a possibility.

240? Get up closer.

might sound stupid but hows your paint to barrel fit? did Tippmann test fire it at their shop? if it wouldnt climb to velocity it would still be in the shop.

The Xcel had a few rollouts and the BOA seemed to keep a tight fit. I didnt take the stock pipe with me. The velocity was pretty similar between the two with having worse FPS on the Xcel barrel.

springs are new and correct?