LX Bolt not locking up

[CaliMagFan]

hey guys here is my issue..

bought a new rt ule custom w/ ult, ule vert body, intelliframe..
--worked great.... shooting all 290's with longest spring and great lvl 10 setup..
--i wanted to use the classic rail cause the foregrip is set closer to the grip frame.
-- the tolerances should be the same for the classic trigger rod and all that, and the on/off pin should be ok.
-- my LX bolt bumper that came with the gun (the softer clear one) got chewed up by the lvl 10 bur, so i put in the classic valve blue one and trimmed it to fit the body circumfrence.
--sometimes i'll be firing and the bolt doesnt come back and lock up all the way. another ball goes into the breach, the trigger has pressure and can be pulled, but the sear does not seem to have locked up the bolt, and thus, i cannot fire another round.
-- i can stick my finger in the feed tube and click the bolt back into place by hand.
--this happens with the longest spring and the middle spring, both with and without paint.


why do you guys think this is happening?... anything other than the rail swap gunna fix this... i'm pretty sure i'm right on my number of LX shims, carrier size and spring size.... any help would be great.

thanks

-kyro

[Dayspring]

First of all, your on/off pin is the wrong length.

The RT Pro ULE Custom uses a .765 pin. The Classic rail uses a .750 pin. That's #1.

Second, you need to add a shim or two. The bolt not resetting is a symptom of bolt stick. by putting a shim in, you are venting the excess air behind the bolt and allowing it to reset fully.

[the electrician]

is the classic rail thicker than the rt ule custom rail?

does it still do it if you hold the trigger back after it fires?

[CaliMagFan]

i dont think this is a lvl 10 shim issue cause i add one and it makes it leak.. and i know its a shim leak not a carrier leak...

yes, when i get it to fire i can hold the trigger back, but it does nothing to help lock up the bolt...

i have now switched back to the original RT rail, still the same problem, with the same frequency of occurance... mind you that i was able to fire a care or more with the classic rail on before a problem cropped up at all.... now the problem persists on either rail....i cant see how i might have done irreperable damage, certainly i cannot find any.

i have taken the whole valve apart, cleaned it all, oiled the on/off and the reg assembly..

my last guess is that there might be a deformity in my vert ule body.. i'll look at it tomorrow at some point...

any help is great guys..

thanks
kyro

[athomas]

Maybe the carrier o-ring has swelled a bit. Try going with a larger carrier.

[DeerChaser]

I had the same problem, I fixed it by snugging down the field strip screw with a allen, not fingers. I think the ULE body gets warped if you don't have the same tension on both mounting screws. It doesn't take much to throw things off.