Tac-1/Level 10 issues

[Silence]

I bought a Tac-1 in February direct from AGD. It came factory tuned. At first it had some bolt stick issues, but after putting several cases through it that faded away. From April to now it has performed perfectly. I've cleaned it religiously and kept it well oiled.

Yesterday I put about 3/4 of a case through it during rec play and, again, it worked fine. I didn't have time to clean it right away, so I put that off till today. Broke it down, oiled it up, put it together. Here's where the problem starts.

I screw the air tank in and the bolt sets fine. No leaks even if I try to wiggle the bolt around. When I pull the trigger, though, it goes full auto as long as I have the trigger pulled. The bolt resets properly when I release the trigger. If I stick a squeegee in there to test the level 10, the bolt bounces off, only half resets and air leaks down the barrel. If I push the bolt back a little and release, it fires and resets properly.

At this point I had the carrier with one dot (0.5 I believe), and three shims installed.

Things I've tried thus far and the results:

1) Theory: I didn't put it together properly/clean it properly/broke something while cleaning.

Test: Re-cleaned it all and made sure I didn't screw anything up. Checked out the shims to make sure they weren't bent, etc. Put it all back together.

Result: Same symptoms.

2) Theory: Maybe I need less shims.

Test: Removed one shim.

Result: Same symptoms.

Test: Removed all shims.

Result: Full auto with trigger pull. Did not test level 10 anti-chop.

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edit: One tidbit that might be important. When I was chronoing in at the field, I was shooting pretty low (220) for a while, even while doing the X-Valve chrono technique. I had to turn the reg up what seemed like quite a bit before I started hitting 260-280 (maybe a quarter turn or so? can't remember). Could I have screwed up the regulator?

At this point I'm running low on air (I didn't get a full fill from the field when I was done) so I figured I'd appeal to this forum before I blundered further. Maybe another re-cleaning is in order?

Warning: Total noob here! This is my first mag and I'm just going on what I've read in the manual and (possibly incorrectly) deduced from using it. Any help is appreciated!

[Silverback]

Do you have a ULE trigger?

Did you tear down the on/off valve while cleaning?

If no to both questions, don't mess with the on/off yet. Replace o-rings in power tube, relube well. try again. If still full auto, replace on/off o-rings. that should fix it, if not, let us know.

[Silence]

Do not have a ULE trigger.

I replaced the o-ring that sits in the carrier, lubed it up, and tried that. Same symptoms.

It looks like the parts kit that comes with the gun does not have a replacement for the o-ring on the powertube tip or replacements for the on-off o-rings. I'll order some up now and give that a shot.

While I'm waiting though, does the velocity issue sound fishy at all? I've never broken down and cleaned the regulator, assuming that it would be a bad idea. Should I give that a shot?

[FiXeL]

Sounds to me your on/off is not sealing properly. This could either be:

A: Badly leaking/missing o-rings in your on/off
B: Trigger rod was not secured with locktite and screwed in a little, thus the sear is not closing the on/off properly, causing short stroking the gun

That is the only thing i can think of. If the on/off works ok it should seal the air chamber from the reg when pulling and holding the trigger.

[Silence]

I took a look at the trigger pin, but that seems to be locked in place pretty well. I re-checked the on/off just to make sure I didn't leave out an o-ring, and that looked fine too. (I'm also ordering just about every o-ring for the gun right now, to have for next time)

This morning I decided to bite the bullet and see what the inside of the x-valve looked like. So I took it apart and lo and behold, it looks like the middle plastic spacer/o-ring on the tip of the reg valve pin has a crack in it! I'm adding that to the basket. All of the other o-rings look fine - no cracks, well oiled, no obvious wear.

More theories, tests and results to come.

[Silence]

Well, my face is red. For two reasons:

1) I read the stickies in more detail and discovered that the spacer is supposed to have a split in it. Oops. Never hurts to have extra parts, though.

2) When I said I was "low on air" the needle was telling me about 1100 PSI. I'm guessing the needle was wrong - I went and got it refilled, gassed up, and voila! No problems at all!

Lesson learned: Never, ever try to tech an automag with anything less than full output pressure.