Shootdown in ULE body

[AzrealDarkmoonZ]

I have an Xvalve, LVL 10, ULT trigger. I slap it in the ULE body and it works at around 3-4 bps anything beyond that and it starts shooting down. If I put it in my old classic body it shoots just fine with no problems.

Any ideas?

[Ando]

Are there any kind of mods done to the ULE body, frame, rail?

[AzrealDarkmoonZ]

Nope.

[OPBN]

Does it make a difference if you take out the detent?

[factoid]

Describe your shootdown? Is it a steady FPS at 3-4bps and then any faster and it starts going like 250, 210, 200?

Or are you getting like 3-4 normal shots and then it starts chuffing?

Is everything in place correctly on the ULE body? Detent is on tight (but not too far into the body that it's sticking on the bolt) and the feedneck is screwed down well? Does it have the washer and c-clip in place properly?

[Spider-TW]

I would suspect the ULE body sits lower and thinner than the classic body, giving you effectively a longer on/off pin. The classic body may be thicker or slightly warped, so that it lifts the valve up a little higher. You might measure the bodies' thicknesses and lay them on a flat table and check them for warpage.

You can check the bolt for detent drag like factoid pointed out. If you have shot it much and it is dragging, you should see some marks on the bolt and in line on the inside edges of the detent.

[Ando]

If the bolt was hitting the detent. It would blow the detent out the barrel. If you had issues with the lvl 10 prematurely activating or paint busting then the detents i would suspect.

Since you have a ULT. I would start off with adding/removing shims and see if that fixes the problem.

If you have a stock on/off in your parts box or on another marker. Install it and see if the problem persists. If it goes away then it's just a ULT tuning issue.

[AzrealDarkmoonZ]

Added four shims to the ult and it seems to work in the ULE. Thanks very much for your guys help!