RAP4 Paintball.... http://www.rap4.com/p/019690/13ci-compressed-air-tank-cylinder-no-regulator-Bob
So here's an update on my QB Ninja. I hadn't touched it in awhile because it was deer season, wx was too bad for testing, etc. I need to pull the front end down, and wanted to chrono test it (on video) in its unmodified condition before I do that.So today I pumped it back up (it leaks down in a couple days) to 2300 psi and chrono tested it. 580 fps avg w/CPHP 14.3 grain. Then I plinked. And plinked. And plinked. I plinked for about an hour and a half and nearly depleted the half-full 500 tin I started with. I shot at least 150 rounds. Yes, it fell out of regulation but was still holding close to the same point POI. And that is starting from only 2300 psi!It still shoots a couple inches right at 25 yards, even after I've worked on bending the barrel. But I plan to put a scope on it and probably remove the irons, so I think the scope will have ample adjustment range to compensate.I really want to keep a high shot count. My intentions are to remove the filter, unshroud the valve inlet, and fix the leak (probably tube to tank block); and nothing else. This is to be the gun that I pump to 3K, take it and a 500 tin of CPHP to informal airgunner meets, and shoot all day.
Today I took the front section off the valve, threw all the pieces parts I found within (except the poppet, of course) into the junk bin, and cut the front off. Threaded the remaining ring back on the valve and cut down a likely looking spring from my bucket o' springs to push apart the poppet and tank block. Smeared some Permatex blue RTV (sensor safe!) on the block sealing surface and slapped it back together.Manana, to re-pressurize and test it.
Because it was leaking before. At least, I think that's where the leak was.
Quote from: WECSOG on February 11, 2016, 10:52:16 PMBecause it was leaking before. At least, I think that's where the leak was.Fairly certain that Permatex blue RTV will not withstand your regulated pressure. I think it is rated around 240psi. If it was leaking there before, it will still be leaking there.That seal should require nothing more than a single o-ring to seal.
Here are the results....The average velocity while on reg. jumped up to 738 fps (17.3 FPE), giving 48 shots starting at 2000 psi before the velocity dropped below 730, and a total of 58 shooting down to 1000 psi.... That works out to 17 psi per shot, and an efficiency of 1.10 FPE/CI.... Starting from 3000 psi, you should get 105 shots down to just under 1200 psi.... This mild mannered gun is beginning to show some real promise.... The Stage 1 mods to accomplish it can all be done with a set of numbered drills and a needle file, plus a rubber seal.... and without removing the valve from the gun....For the next round, however, I will be pulling the valve out to improve the airflow into the valve, and provide more volume between the regulator and the valve to increase the average pressure available during the shot cycle.... I'm really looking forward to seeing the results....Bob
I think the varnish is used differently. It is not in the extrusion gap. It fills in any potential scratches in the O-ring groove. The varnish also pools in the corners to cradle the O-ring and puts it into a little better contact with the tube wall.In any case, I hope you get the leak sorted. Losing air is aggravating.
Bob, Could you make this shoot in the high 800s? Forgive me if you (or someone else) has already stated they have done so in the 11 pages prior to my posting this question).
Quote from: Joe Brancato on February 12, 2016, 11:27:36 AMBob, Could you make this shoot in the high 800s? Forgive me if you (or someone else) has already stated they have done so in the 11 pages prior to my posting this question).Like Jason said - easy to do. Heck my reverse bottled (with a 13ci) QB78 is getting 845fps in .25 (JSB kings 25.4) for 40FPE.My 79 on 1500psi would get 23FPE in .177 so that would equate to 850FPS using 14.3 pellets, and the .22 should be more efficient
Quote from: rsterne on July 16, 2013, 02:20:18 AM Here are the results....The average velocity while on reg. jumped up to 738 fps (17.3 FPE), giving 48 shots starting at 2000 psi before the velocity dropped below 730, and a total of 58 shooting down to 1000 psi.... That works out to 17 psi per shot, and an efficiency of 1.10 FPE/CI.... Starting from 3000 psi, you should get 105 shots down to just under 1200 psi.... This mild mannered gun is beginning to show some real promise.... The Stage 1 mods to accomplish it can all be done with a set of numbered drills and a needle file, plus a rubber seal.... and without removing the valve from the gun....For the next round, however, I will be pulling the valve out to improve the airflow into the valve, and provide more volume between the regulator and the valve to increase the average pressure available during the shot cycle.... I'm really looking forward to seeing the results....BobBob, Could you make this shoot in the high 800s? Forgive me if you (or someone else) has already stated they have done so in the 11 pages prior to my posting this question).If you are interested in getting one to shoot in the high 800's, I have a number of 360 CC (22 Cu In) tanks, and I'd like to send one to you at no charge. I'll even pay the shipping. I'd like to see what can be squeezed out of that rifle.These measure 11.38" (about 4" longer than the 13 Cu In in you initial post). If they fit, I don't mind sending one to you. Heck, I'd even buy the gun if you decide to sell it.You can post here (not sure if I'll see it, but will look), pm, or call me at 714-612-5956
So here's an update on my QB Ninja. I hadn't touched it in awhile because it was deer season, wx was too bad for testing, etc. I need to pull the front end down, and wanted to chrono test it (on video) in its unmodified condition before I do that.So today I pumped it back up (it leaks down in a couple days) to 2300 psi and chrono tested it. 580 fps avg w/CPHP 14.3 grain. Then I plinked. And plinked. And plinked. I plinked for about an hour and a half and nearly depleted the half-full 500 tin I started with. I shot at least 150 rounds. Yes, it fell out of regulation but was still holding close to the same point POI. And that is starting from only 2300 psi!It still shoots a couple inches right at 25 yards, even after I've worked on bending the barrel. But I plan to put a scope on it and probably remove the irons, so I think the scope will have ample adjustment range to compensate.