Nelson Autotrigger

[fullofpaint]

So just finished rebuilding a modified 007. Shoots great, except the autotrigger seems to fire before the breech closes. Is there a way to adjust the timing on these like a Sheridan or is it just through springing?

I'm using a Lapco bolt and hammer, 6P Powertube, and a Line SI ASA.

[Ghost Flanker]

I have no experience with 007s, but if they're internally similar enough to a Phantom as to be accurately represented in the animation below, then I think I can help.


Changing the springs will not help your timing issue. If the gun is able to fire at field velocities, leave the springs alone. Unfortunately, Nelson AT timing is not adjustable like Sheridan AT timing is. However, you may still be able to fix the issue. How far open is the breech when the gun fires in AT?

It sounds like the sear on your gun is being prematurely actuated by the trigger. If Nelsons were in fact designed to AT properly (they were originally bolt action if I'm not mistaken, so I'm not sure if they were ever even intended to AT), then the sear's premature actuation is probably occurring because you're using an aftermarket hammer with a sear that's out of spec. If you have a Nelson hammer and bolt, install those back into the gun and see if the problem goes away. If it doesn't, then make sure the trigger is not an aftermarket part, as well.

If all the above attempts fail, or if you do not have access to the original parts, then the only way to adjust the AT timing is to modify the trigger using a table grinder. The upper rear portion of the trigger is what makes contact with and actuates the sear, and trimming away the precise amount of that part of the trigger will allow the sear, hammer, and bolt to all travel far enough forward (when you pump forward) to close the breech right as the sear makes sufficient contact with the trigger to fire the gun. If this mod is attempted, though, extreme care must be taken to avoid trimming away too much or else the gun will not fire at all, in which case you'll need a new trigger.

[Rusty Brass]

It's probably just a bad sear - either worn out to where it'll release when jostled or it's out of spec for the 007. If it's too tall then it'll get caught by the trigger when the breech closes or if it's too wide it'll get hung up on something in the body/rail/frame. Do you have a different set of guts to swap in?

[fullofpaint]

Waiting on a set to come in. Sear looks fine visually, doesn't look really worn down or anything and AFAIK it's a stock sear not a Lapco or something.

[Rusty Brass]

Sometimes they look fine and just don't work. I had a phantom doing the same thing and the eventual fix was just to throw out the guts.

[Ghost Flanker]

Fullofpaint, does this issue consistently occur when pumping forward slowly while holding the trigger down? And does the gun fire when pumping forward forcefully with the trigger released?

[fullofpaint]

I need to get some paint to confirm, but it feels like it releases somewhere between a 1/4 to halfway through the breech, regardless of the speed of the pump stroke.

Got a spare sear in today so I'll gonna test out some more and report back.

[Jonnydread]

Curious, do you actually use Nelson A/T? I've tried it a few times and it feels like giving a 7-year old an anti-tank rifle.