Timing issues: Sear won't catch

[PlawB]

I'm hoping one of ya'll can point me in the right direction. I'm timing a cocker on a sliding frame. Everything seems to be set as it should, the hammer is released just before the timing rod starts to move. Pump arm moves almost as soon as the timing rod starts moving. But for some reason the damn sear will not catch the lug.

The sear looks in good shape, no rounding.

What am I missing?

[FrankW]

At what point in your trigger pull is your hammer releasing? Towards the beginning? Towards the middle?

It's been a while since I timed a cocker, but I remember it being easier when you have the release towards the middle of the trigger pull. Too early and it tends not to catch reliably.

[Jordan]

The sear spring can cause this, if it's not strong enough.

I've also seen grip screws that are too long restrict the sear's movement.

[RichM]

X2 on the early trigger pull. If the hammer is released too early (right at the start of the trigger pull) the 4-way will cycle the back-block back to the rest position before the sear is high enough to engage the hammer lug on the way back. Once you get to around half-way through the trigger pull the sear should be high enough to catch the hammer lug on the way back.

[OpusX]

Yep. Screw the lug down a touch more for extra engagement.

[Fubarius]

Don't forget to check the cocking rod length, and how much the back block is screwed into the pump arm.

Either can cause the hammer to not travel far enough back, so the lug will be too far forward when you release the trigger.

[Trbo323]

Don't forget to check the cocking rod length, and how much the back block is screwed into the pump arm.

Either can cause the hammer to not travel far enough back, so the lug will be too far forward when you release the trigger.

This is what I was going to suggest as well

Hold the trigger back and then pull the cocking Rod by hand, is there a lot of extra length you can pull the hammer back?

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[PlawB]

You guys are the best! So, I've definitely identified a few potential causes I'm going to investigate. The sear spring looks squishy. I got a good hardware store near me so I'll try to find a stiff spring there. The backblock and cocking rod are definitely suspect as well! I was definitely trying to get the backblock as close as possible and I think the rod is too short. Also, the IVG was seriously cranked in by me and it's a bear to cock the hammer. At least now I don't feel like I'm hitting my head against the wall.

[PlawB]

IT'S ALIVE! After a solid month of messing with this thing it is ripping! THANK YOU to everybody.

Here's what I fixed: Unscrewed the backblock an extra turn. It's not as close as I'd like but whatever. I also changed the cocking rod to have the bolt come back even more. A little more than I'd like but I'll just wait and see if I get double feeding. And the main thing, which I think was the biggest culprit, was I put the IVG to a normal position. I had it really far forward, past the screw hole for the beavertail, since I'm always worried about the beavertail screw being too long and hitting the IVG. I noticed before that there was a lot of recoil and it was hard to cock the gun. I'm thinking there was too much tension on the spring and the hammer was being forced forward way too hard.

Of course this is not the end of our little journey. Still to do: Fix my palmer's rocks (one that came with gun and old one in storage simply weren't working. I think that's an issue with the seals and with cleaning), put the larger rock on this thing, put the sledgehammer back on my main cocker, sweetspot the reg, and chrono this puppy. There are also some teflon taped parts I need to do with loctite.

I can't wait to get this all done and then never mess with this thing again for as many years as possible. Definitely going to be playing with it, though.

[Seajay]

You guys are the best! So, I've definitely identified a few potential causes I'm going to investigate. The sear spring looks squishy. I got a good hardware store near me so I'll try to find a stiff spring there. The backblock and cocking rod are definitely suspect as well! I was definitely trying to get the backblock as close as possible and I think the rod is too short. Also, the IVG was seriously cranked in by me and it's a bear to cock the hammer. At least now I don't feel like I'm hitting my head against the wall.

Oooo I'd re-adjust the cocking length back to where you think it should be and retest now that you've put the IVG in the correct position.
You probably had wayyyyy too much tension so the hammer wasn't able to travel all the way back. If the IVG was that far forward it would also change the timing a little when put in the correct position, because all the other moving parts can travel correctly now.