Classic RT issues continue!

[Kajo]

All,

Just got back from another day of paintball yesterday. The second day using my new (used) classic RT. Unfortunately, I couldn't get the thing to shoot a single ball at a time because of the OVER reacting trigger and had to use a rental. I mean I was literally pulling and shooting off a string of 3 or 4. Of course with no level 10 it turned into a blender real fast.

If you remember my thread from last time I had a leak coming from the banjo bolt. So between then and my day yesterday I disassembled the marker, cleaned, replaced the banjo o-rings and reassembled.

What is making this thing RT like crazy?

Thanks!

[pbjunky99]

how much of a gap do you have between your trigger and sear rod? There should be a space between them.

[1stTarget]

Input pressure. My RT loves a certain pressure on supply side, with the regulator adjusted just right. 1100 psi input, 260 fps. Rt of one on pull, one on release. Tuning is fast if have adjustable reg. Once sweet spot is found, it is great. Turn down just a little it is only semi, tune too high it is a auto.

[Kajo]

In reference to gap I'm assuming I should check this with the gun aired up?

Also - both times i used preset tanks. They were different brands. I don't have my own air tank so I just rent one at the field.

[Ando]

In reference to gap I'm assuming I should check this with the gun aired up?

yes

Also - both times i used preset tanks. They were different brands. I don't have my own air tank so I just rent one at the field.

That might be it in a nut shell. No 2 regs are the same. Especially different brands.

Ck the 2 top on/off orings. Well, depending on your valve, you might just have one in there but just make sure it/they aren't messed up or missing all together. Just replace it/them to completely rule the on/off out. One last thing would be measuring the on/off pin. A stock mech pin should be in the neighborhood of .750" and a stock Emag pin should be in the neighborhood of .712". I set my mech pins in around the .730" mark, makes for a nice RT effect when I need it.

[Kajo]

Shouldn't the internal reg in the gun take the pressure down to something usable?

I'll grab a vernier from work tomorrow and measure my on/off pin. I'd rather keep it longer if it means I won't be RT'ing all the time. I play rec and I don't really need all that firepower, especially if I can't control it or if it is inconsistant.

[wimag]

we spoke on saturday.

Check your bolt spring. Check the bolt lip and sear where it catches the bolt so see if it is rounded off. I run a .750 on/off pin in all my RT's

I have had this happen numerous times and it came down to on of ones listed. Do the bolt spring.
Who knows...once you get a level ten in there it may fix it.

[kcombs9]

Shouldn't the internal reg in the gun take the pressure down to something usable?

Yes but that is not what is in question, you can use a tank that is set from 800 psi up to 1100 psi. and still shoot at 280 fps. but the gun reacts different to the pressures.

the higher the pressure the MORE RT effect you get.

but seeing as you use field preset tanks I would be suppressed if they are set any higher then 800-850psi. as most guns don't run on anything higher then that.

check your sear and bolt make sure they are in good shape, take some pic for us to see, if either or both are worn down you could just have a case of the sear and bolt going into full auto cause they don't connect properly and stop the cycle

[athomas]

Yes, it definately could be a worn sear tip. That would make for an overly reactive valve.

[Kajo]

Ok guys,

Thanks for the help (AGAIN!). I will check the sear and bolt spring. It's just weird that I could get single shots out of the gun three weeks ago but when I went to gas it up this time I couldn't get anything other than 4 to 6. Maybe the sear was not quite worn out and I finally sent it over the edge.

I will report back.

[athomas]

Did you change all the orings in the valve as you mentioned you were going to do? Any oring leak that allows air to flow into the valve can contribute to reactivity.

[Kajo]

All,

Just got done disassembling the entire marker. It is now in pieces on my work desk. I will reassemble tomorrow.

For the most part the o-rings looked like they were new and in pretty good shape. The one issue I did see was that the middle banjo o-ring was nearly cut through. I JUST replaced them Friday night before Saturday's paintball day so I'm going to assume that I cut the thing putting the Banjo bolt in or taking it out. My banjo bolt goes in and out relatively easily if I lube it and DO NOT gas the gun up. However, after gassing the gun up and degassing it's a real pain to get the banjo bolt out. I always need a pliers.

I checked the bolt spring against the one in my spare parts kit. Unless the one in the kit is used (a possibility) it feels ok. Both springs compressed similarly under my "calibrated" fingers. Not sure how else to tell if the spring is failing.

I took a vernier to my on/off pin and got .7415" so I do not think the length of the pin is an issue. If anything I should be RT'ing less.

Pictures of the sear are at the google picasa link, sorry if they are a little hard to make out. It's damn tricky to take a photo of the wear. Having no other sear to establish a baseline I really cannot say much about it. The edge where the bolt catches seems to be reasonably good. The on/off portion is rounded.

https://picasaweb.google.com/106337693851443932562/AutomagRTSear?authkey=Gv1sRgCJKAnbXT5JmwZA&feat=directlink

[athomas]

The sear doesn't look bad, although it is hard to tell with the pictures a bit out of focus.

A worn bolt spring will make the marker have bolt stick, but it won't make it go full auto.

The on-off pin length is fine. It shouldn't have uncontrollable reactivity with that length.

Full auto causes:

1) worn sear tip, which allows the bolt to slip off the holding surface when air fills the chamber.
2) short on-off pin, which allows air to charge the front chamber before the sear catches the bolt.
3) bad oring(s) in the regulator section of the valve, which allows air to flow into the front chamber even though the on-off is closed.

[Kajo]

Guys,

I am still at a loss for what to do about the extreme reactivity.

Per athomas my sear and on/off pin are ok.

The o-rings look pretty fresh. I guess I can just order a parts kit, replace them all and hope for the best. I'm a little leery about throwing a lvl 10 in without getting the gun functional in lvl 7. I know I am going to have issues to address with the lvl 10 and I don't want to bring any other variables into the equation.

Anyone in Milwaukee have access to parts/air and want to help me out (that's good with mags)? I have no problem spending money on parts for the thing but I'd like to know what parts I have to swap before I start buying everything available on the AGD site.

[rawbutter]

You, sir, seem to have yourself a puzzler. At least you're smart enough to hold off on the Level 10. Order yourself a parts kit instead (even if it doesn't fix the problem, it's good to have one on hand for the future), replace all the o-rings, and see what happens.

Also worth replacing is the bumper (the big, blue flat washer-like thing that sits between the valve and the bolt... it looks like this).


The bumper acts as a cushion to keep the bolt from bouncing back when retracting. If yours is worn, it won't absorb that impact as well, so the bolt may be bouncing a few times before settling. This is unlikely (bumpers are supposed to last forever), but still... they do die occasionally. Best to be thorough.

The good news is that a bumper should come in your RT parts kit, so at least you don't have to buy it separately.

If all that doesn't fix it... I don't know. Your sear DOES look fine to me. Your on/off pin is within specs... If replacing all the o-rings and bumper doesn't do the trick, you may need to send it off somewhere.

Good luck.