Museum

[glaman5266]

My girlfriend gave me an old BE Cobra pumpgun for X-Mas. Shoots super-straight and is actually a decent performer for as old as it is. I konw this thing is old and should probably be in a museum (lol), but I want to use it as my primary pump.

I was wondering if there are any tweaks and/or tuning to get increase it's performance a bit.

The main issue is velocity. I think the adjustment has to do with the hammer length (2-piece, threaded). I'm also going to have a look at the valve body (or whatever valve is in the front) sometime and do a tear-down if necessary- the valve pin is hard to move (possibly siezing up?).

Any suggestions/input would be appreciated.

[olderthandirt]

Originally Posted by glaman5266

Any suggestions/input would be appreciated.

Hi Glaman...

I tried to post here earlier but the interface timed out. Anyway, to paraphrase what I was saying, if your valve is ok, ie not leaking I'd leave it alone. Just make sure you "overlube" the marker through the ASA, and clean your barrel out before playing.

I used to own a King Cobra many years ago and the biggest problem with changing the hammer spring was the ASA o-rings. They used to get cut on removing or installing the ASA which causes a leak. The Cobra/King Cobra has a channel in the body which leads from the ASA to the valve. It allows CO2 to pass from the ASA to the valve. Any defect in the ASA o-rings will cause a massive leak. So have spares on hand. You'd be surprised what plumbing o-rings can do. Also, if you've got a tank with an on/off valve, that would be the best bottle for this marker as you'll be able to shut it down the minute you get a leak in the ASA. Note the ASA also has a pinhole in it for removing the bottle and allowing gas to vent off during removal.

If your shooting at around 285 fps in optimal conditions, apart from a cleaning the marker is working well. The only real velocity tweak you can do is to alter the hammer spring. Experiment with a replacemnt nelson hammer spring not the original. If I remember rightly the hammer spring is slightly longer than a standard nelson spring. To get the ASA back in without tearing the o-rings is going to be a challenge. If you remove burrs on the inside of the marker body, do it very carefully. I used to lube everything to make it all slide nicely. These days I'd use that o-ring paste on the o-rings.

Don't make a hasty trip into the valve. I'd avoid cutting the valve spring! Its unique! Again if the valve is not leaking taking it apart is not really going to help. The cup seal can be flipped if it is damaged. As a last resort, you can remove and sand the disc with a fine emery paper to remove scratches. I used to do this with Stingray valve seals, and it works.

If you can clean the marker internals, and replace any o-rings you find without going into the valve that would be your optimal choice.

In my earlier inexperience back in the day, I had problems getting the King Cobra to work in our variable environment which is either unpredictably cold and wet, or hot. So finding a happy medium was always a problem which became frustrating. The velocity was usually either too low, or too high. You'll have to experiment to get a hammer spring(s) that will do the job properly. Eventually, you'll learn as I did that you have to accept what you get or give into the repetition of teardown and re-assembly. In the latter case you need extra ASA o-rings to take with you, and have a backup marker just in case.

Good luck

Greg
:-)

[Gunnar_dude]

I just picked up a nice King Cobra from Jesterbuilt (thanks again man!) and tore it down for cleaning and need to replace the o-rings on the ASA. Any suggestions on what to size or material to use? When I played a lot with my Nelsons, a black o-ring was a black o-ring (and I work at an airplane factory that has lots of them) the o-rings in the Cobra are/where white. I checked out paintballorings.com and noticed they sell buma and in different duro's. I'm a little lost.

[glaman5266]

Wow... this thread was brought back from last February...

I have my Cobra working like a charm and shooting in the 260-270 FPS range.