Bolt not resetting properly

[Shirow]

I just basically rebuilt my entire gun. Venomous rail, new RT sear, ULE body, J&J edge barrel. Only thing from my old build was my intelliframe and valve.

First problem, the sear was catching on the edge of the trough it sits in inside the rail. I had to tighten the sear pin precisely to give it free motion, so I did that and it seemed ok.

Second problem, the screw for my intelliframe would not reach the hole in the ULE body to tighten it down thru the rail. I got a longer screw from the hardware store, seemed OK.

Now, when I gas it up, the trigger rod has pressure behind it. If I lightly touch the trigger just enough to fire, it shoots ok. If I push it ANY harder, it chuffs, balls roll out the barrel or break in the barrel and the bolt sticks back. When I let go of the trigger, the bolt resets.

If I loosen the field strip or screw thru the intelliframe, it gets a LITTLE better but it is still basically unusable.

Any ideas? Velocity is good, tank is good etc..

[secretweaponevan]

What valve and bolt are you using?

What gas source are you using?

What is your setup? (on gun? remote?)

[Shirow]

ReTro Valve with level 10 (level 10 shot wonderfully before the change, running 1.5 carrier and 3 shims) I did try changing to the 2 carrier just to see if it was the level10 but I'm not sure, because of the strange performance I thought it was more like a tolerance issue.

Using a flatline, mounted to gun, output is around 850psi. Flatine also worked great pre-build change.

[athomas]

I don't know that much about the venomous rails. The rail should be the same thickness of a regular rail so the same frame screw should have fit. That fact that the sear pin tension affects the sear means the rail is flexing. I would check the rail out to see if it is causing other issues as well. If you have your old rail, try it with all the new parts.

[secretweaponevan]

Make sure your trigger rod has the 1/16" gap between the back of the trigger and the tip of the trigger rod with the marker gassed up and the safety on.

Turn up your velocity. (your most likely culprit)

Use oil.

Are you using a ULT?

Edit: Man. athomas. Still, I learn something new from you every day.

[Shirow]

I don't know that much about the venomous rails. The rail should be the same thickness of a regular rail so the same frame screw should have fit. That fact that the sear pin tension affects the sear means the rail is flexing. I would check the rail out to see if it is causing other issues as well. If you have your old rail, try it with all the new parts.

That's what I thought and was worried about. I will try the old rail, just annoying because it means I have to knock the twist lock assembly out to use it with the ULE body

[Shirow]

So, it *looks* like the problem is that the body doesn't sit quite flush into the rail. If you just snap the body into the rail and look straight down the side of the body, you can see light shining thru from the holes in the rail. I assume it is supposed to fit flush. This is probably why my frame screw doesn't reach through into the body properly either.

[athomas]

It means the pocket where the pim sits is not deep enough. You can compensate by sanding the end of the pim until it doesn't make contact and the body sits flat on the rail.

[Shirow]

It means the pocket where the pim sits is not deep enough. You can compensate by sanding the end of the pim until it doesn't make contact and the body sits flat on the rail.

The 'pim' being the part that the screw goes into on the body?

Do you think that is the only cause - it can't be any other part of the rail causing the issue?

It almost seems like it's a little farther back.. there's a raised piece to the left of the sear that it seems like it might be catching on. It's very hard to tell though.

[athomas]

You are correct. The pim is the threaded protrusion on the bottom of the body. It shouldn't bottom out. If it does, the body will not sit flush and the valve/bolt/body/rail will not line up properly and will cause all sorts of operational problems. Get that part fixed first. Then, if there are still problems, we can move on to fix those.

There could be other parts causing improper contact. Only you will know that by looking at it very closely.

[Shirow]

You are correct. The pim is the threaded protrusion on the bottom of the body. It shouldn't bottom out. If it does, the body will not sit flush and the valve/bolt/body/rail will not line up properly and will cause all sorts of operational problems. Get that part fixed first. Then, if there are still problems, we can move on to fix those.

There could be other parts causing improper contact. Only you will know that by looking at it very closely.

Yeah. I think I'm just going to contact Mongoose and see what he can do to fix it - I don't really want to have to modify every body I want to use on this rail to get it working. Thanks for your help!

[Shirow]

If anyone else had this problem, for reference this appears to be the problem area:



It's hard to tell exactly but it seems to be either the concave surface by the sear pin where the body sits or the thin, standing up piece of metal halfway between the venomous serial number tag and where the sear pin goes through. If I push down on the body in that area, it raises it up from the front of the rail about 30-50mm or so. Definitely doesn't quite sit flush there.

[athomas]

It's hard to tell exactly but it seems to be either the concave surface by the sear pin where the body sits or the thin, standing up piece of metal halfway between the venomous serial number tag and where the sear pin goes through. If I push down on the body in that area, it raises it up from the front of the rail about 30-50mm or so. Definitely doesn't quite sit flush there.

If the pim is bottoming out it will act like pivot doing exactly what you are describing. Although, I suspect you mean 3 - 5 mm.

[Shirow]

If the pim is bottoming out it will act like pivot doing exactly what you are describing. Although, I suspect you mean 3 - 5 mm.

I do indeed. Thanks!

[Mongoose]

I just basically rebuilt my entire gun. Venomous rail, new RT sear, ULE body, J&J edge barrel. Only thing from my old build was my intelliframe and valve.

First problem, the sear was catching on the edge of the trough it sits in inside the rail. I had to tighten the sear pin precisely to give it free motion, so I did that and it seemed ok.

Second problem, the screw for my intelliframe would not reach the hole in the ULE body to tighten it down thru the rail. I got a longer screw from the hardware store, seemed OK.

Now, when I gas it up, the trigger rod has pressure behind it. If I lightly touch the trigger just enough to fire, it shoots ok. If I push it ANY harder, it chuffs, balls roll out the barrel or break in the barrel and the bolt sticks back. When I let go of the trigger, the bolt resets.

If I loosen the field strip or screw thru the intelliframe, it gets a LITTLE better but it is still basically unusable.

Any ideas? Velocity is good, tank is good etc..

If your using a new/different body, your going to need to re-tune your lvl 10. Do it using your old parts. Then swap in my rail and try it out, also take out the sear screw and make sure there isnt any residue from polishing/anno,

Lets see if that fixes any of your problems, Once we make sure that the rail is defected i will gladly fix/replace it for you

Christian