ULT Trigger issue

[gmiller0]

Is it possible that my ULT On/Off could create bolt stick? My ULT works great on my level 10 xvalve with the softest spring which gives me good reactivity (excellent burst shots) but.... as soon as I moved up to the red spring to be easier on paint, weird things started happening. I had the velocity turned up and I get bolt stick after the 3rd shot or so and air starts rushing down the barrel. If I use the R/T on off its fine... UGH

[athomas]

Is it possible that my ULT On/Off could create bolt stick? My ULT works great on my level 10 xvalve with the softest spring which gives me good reactivity (excellent burst shots) but.... as soon as I moved up to the red spring to be easier on paint, weird things started happening. I had the velocity turned up and I get bolt stick after the 3rd shot or so and air starts rushing down the barrel. If I use the R/T on off its fine... UGHIf the ULT has too many shims installed, it opens too soon and allows air into the chamber before the bolt is fully reset. This air prevents the reset so it continues to leak out the front. The shorter springs and faster bolt movement don't exhibit the problem as often as the softer setups using the stiffer springs.

[gmiller0]

So... Is that why I actually get reactivity with more shims on the shorter softer spring? I could easily relax my finger on the trigger and rope 15 rounds easily, while when I put in the medium (red) spring to be easier on paint it won't react that way at all? Ugh.. So now I have to decide which setup is better:( shooting radical bursts or better paint protection... I love my mag!!!

[athomas]

The reason for greater reactivity with the shorter spring would be partly due to the speed of the bolt return and air leakage, but mostly due to the greater differential pressure between the chamber pressure and the input pressure when using the short spring compared to using the long spring.

[athomas]

When you do encounter bolt stick and air leaking down the barrel, does it eventually stop and reset, or does it require a manual reset by pushing the bolt back into place. If it manually resets by itself after a few moments, then your problem is just bolt stick due to a carrier that is too tight. If it always requires a manual reset, then you need to remove a shim from the ULT.

Either way, you need to address the issue or you could have problems at some point while in a game. Removing a shim from the ULT won't adversely affect the reactivity if it is the cause of the bolt stick. If the problem is bolt stick due to a tight carrier, using a shorter bolt to make it work will only mask the problem. It should be fixed.

Fix the problem so your mag will work optimally and you will be able to tweak it for best performance.

[gmiller0]

Got it.. So I removed a shim and no more bolt stick with the ULT... I have a 1200 psi output cause I got a set reg installed from ninja paintball.. Got a little bit of reactivity for mini bursts but not as effective as the shorter spring and having 2 more shims in the ULT.... Now just gotta figure out if I want reactivity while risking a little ball chop, or, great semi auto action with medium spring.. I use a Dye Rotor so I know it feeds fast enough.... Hmmmmm

Thanks man!!! You guys are great!! :bounce:

[gmiller0]

I have my Level 10 tuned perfectly, as the next bigger carrier leaks a hair so I know I have the right carrier... I can put my finger in the breach and I can barely feel the bolt when I fire and it resets fast.... It hit pretty hard with the softer spring and I could chop a ball if I hung it in the breach with tape.... Ugh... Decisions decision decisions

[athomas]

It sounds like you have the proper carrier.

For testing how hard the bolt hits, make sure you do that where you have access to a chronograph. If you just swap springs without readjusting the velocity, the shorter one will hit a lot harder just because you will still be using the higher chamber pressure for the stiffer spring. If you adjust the velocity back down to the same velocity level you were using for the stiffer spring, then the shorter bolts spring will also have pretty good anti-chop capability.

[gmiller0]

I hear a man... I have a chronograph I bought for $80 that works awesome... I re-chrono'd my gun after I put the softer spring on and it hits pretty hard and does not save more brittle paint, but the gun retros like a son of a gun... Wish I could have my cake and eat it too!!!! Lol :shooting:

[gmiller0]

Ok.. so i played yesterday and I had a problem that if my gun was sitting for more than a few minutes waiting to engage people.. it would chuff a paintball or not even fire, then when i finally got it to fire it shot good... I think the medium spring is not good for my setup unless I can chrono in at just a hair under 300 (the field was under 290 fps). The gun would more often than not, shoot and air would fly out the barrel, and the only way to stop it was to use a squeegie or turn the air off and back on.. Im sure I have the correct carrier cause the next one up leaks.. Ugh.. I thought I had this all figured out.. but when I go out and shoot in the backyard to test it, I never just let it sit for 5 minutes so I never experienced an issue:(

Another dumb question...is there a difference in recharge rate with running a remote hose rather than the tank on the gun?

Also, is it possible to cut a little off the medium spring in order to "tune" it to be able to handle a lower fps for my gun?? If so, is there a theory on how much to cut for any given fps.. ie: 1/8 inch for (x) amount of fps??

[athomas]

Recharge rate will usually be better using a bottle on the gun than through a remote line.

If the gun won't fire after it sits for a while usually indicates a carrier that is too tight. Since your next carrier up causes a leak, then you will probably have to wait until the oring gets broken in. It will function better after that.

As a rule of thumb, your operating velocity should be about 20fps above the lowest velocity that the gun will cycle at. So, if the gun starts cycling at 260fps, then the optimum operating velocity for maximum anti-chop and consistent operation is 280fps. If your lowest operating velocity is 280 fps and you wish to operate at 285 fps, then you need to go to the next shorter bolt spring. if the next shorter bolt spring goes too much lower in velocity, then start snipping some off the longer spring to gradually adjust your operating range. Always remember to put the cut end against the bolt. If the cut end is put against the front washer it could thread its way into the breach area.

Cutting the bolt spring is a matter of guess. Each gun is different depending on barrel setup. You'll have to cut and check how much change you get.

[gmiller0]

Recharge rate will usually be better using a bottle on the gun than through a remote line.

If the gun won't fire after it sits for a while usually indicates a carrier that is too tight. Since your next carrier up causes a leak, then you will probably have to wait until the oring gets broken in. It will function better after that.

As a rule of thumb, your operating velocity should be about 20fps above the lowest velocity that the gun will cycle at. So, if the gun starts cycling at 260fps, then the optimum operating velocity for maximum anti-chop and consistent operation is 280fps. If your lowest operating velocity is 280 fps and you wish to operate at 285 fps, then you need to go to the next shorter bolt spring. if the next shorter bolt spring goes too much lower in velocity, then start snipping some off the longer spring to gradually adjust your operating range. Always remember to put the cut end against the bolt. If the cut end is put against the front washer it could thread its way into the breach area.

Cutting the bolt spring is a matter of guess. Each gun is different depending on barrel setup. You'll have to cut and check how much change you get.

athomas... you were completely correct... the problems I had was a result of me not really understanding the spring parameters... So, after you and Factoid schooled me, I proceeded to learn that I needed a spring that started cycling around 250-255 fps in order to shoot at 275-285 fps with good anti-chop capabilities.. So, I started to cut my red spring down in small 1/5th incriments and test after each cut. I got it down to start cycling at 255+- instead of 275 which after following the +25 fps rule had it shooting perfectly around 280-285 fps :bounce:

Thank you :hail:

[athomas]

Good to hear you got it working. :clap: