6 replies to this topic

[shmmee]

Hi,

I've modified a secret shot II with a duel action bike hand pump (which also has a pressure gauge integrated into the handle to help avoid over-pressurizing.) and re barreled it in brass to shoot micros. It worked very well for an entire day of Nerfing, but when i fired it again a few days later it discharged with a half-second hiss instead of the explosive pop that I've been hearing. The air tank does hold pressure until the trigger is pulled. It just discharges slowly.

I haven't made any other mechanical alterations to the tank, or trigger and I don't see any obstructions in the barrel. Any thoughts on causes and repairs? Would shooting silicon lubricant down the barrel and into the chamber help? I'm not sure about the internal workings of this tank. It might be a big brother of the secret strike (Two air chambers with depressurization of a smaller one instigating depressurization of the main- barrel side tank. There has been a fabulous write up by:
iknowmy3tables - http://nerfhaven.com...254&hl=revealed describing the secret strikes internal workings so I won't go farther into it.) The white firing pin coming out the back leads me to suspect the dual air-chamber set up. Perhaps the stopper on the barrel side tank isn't getting out of the way completely? I'm not sure. I anyone could offer any help or insights into the matter I'd appreciate it.

Thanks,
Shmmee

[Draconis]

You ow doubt have removed the barrel peg, right? It is likely that a small piece of debris has gotten lodged in the piston area, and is not allowing for full retraction. It is also possible that the piston just needs some lubrication. Silicone spray is a bad idea. Using a llittle mineral oil might work.

Edited by Draconis, 22 May 2010 - 02:26 AM.

[snakerbot]

There's nothing wrong with silicone if he gets the right type. See http://nerfhaven.com...showtopic=16267 for more information.

I do agree with Draconis though. Something is likely in the valve. Put some form of lubricant down the barrel (try to get it all the way back to the valve) and pump the gun and fire. This might shoot out whatever is in the way.

[Draconis]

There's nothing wrong with silicone if he gets the right type. See http://nerfhaven.com...showtopic=16267 for more information.

The operative phrase being "the right type", you surely must know that the petroleum disillates in silicone spray are what makes it a poor choice, right? If you are going to link to a thread, make sure you read and understand the whole thing.

[shmmee]

I've lubricated both the barrel side (hopefully some got in) and in through the air in let tube and fired until puffs of lubricant started firing out of the barrel. Performance is improved, but it's still not where it was. Could it be possible that the check valve (one way valve) separating the two air chambers could be faulty, allowing an excess amount of air to shoot back when the secondary chamber vents? Guess i could discharge it under water and see where the most bubbles are coming from...

[shmmee]

Progress... After repeated low pressure firings it now works at about 25 psi (a pump and a half) it gets it back to about stock ranges. I was able to fire it at about 40 psi with a pop.

[shmmee]

You're right on track, and for the benefit of other readers: This isn't just a one-shot "cure" it is more like "therapy" ... don't pump it up high, but pump and fire a bunch of times, holding the blaster at different angles, but mostly downward. The goal is to help whatever it was get all the way out.

So it would seem. After what must felt like 100+ low pressure firings, it's back up to firing at 30-35 psi. A few more should have it back to where it was earlier.

Thanks all for your advice.