Autococker Problem - Sear not Catching Hammer? Hammer Slipping

[heit1_32]

Hello autococker experts! I've got a mystery for you to help me solve! I took a video:

https://streamable.com/vemy90

With no air pressure I can cock and release the hammer with no issues. I have it set conservatively in the stroke to ensure the hammer lug is far enough down.

With air pressure and normal firing the hammer is constantly slipping. It's as if the trigger sear doesn't rise fast enough to capture the hammer. Once I start releasing the trigger very rapidly it catches the hammer every single shot.

Already tried: replacing RAM, replacing LPR, adjusting LPR, adjusting hammer lug, adjusting timing. I've actually got this same problem happening on a trilogy as well with similar troubleshooting and no resolution. I have not tried replacing the hammer lug on this one but I did put a brand new lug in the trilogy and it did not resolve anything. Tried a different frame on the trilogy also with no resolution. HPR is at 270ish PSI.

Why in the world would these autocockers work perfectly fine when rapidly releasing the trigger but when firing normal it slips or short strokes?

All I can think is an issue with the sear or hammer lug but I've swapped frames and lugs without resolution on one marker and now I've got the same problem happening on a Prostock. I'm hopeful someone has seen this before!

Thanks!

[JohnB]

Is the cocking rod seated all the way in the hammer?

[heit1_32]

Yes sir. I'll go ahead and try it with a different cocking rod as well. The rear block is pushing it all the way back past the trigger sear, if I hold the block in the rear position, release the trigger, and then release the rear block by hand, it captures the hammer every time 🤯

[superman]

Have you tried spacing the timing out more?
What lug are you using? round, square, cone?

[heit1_32]

I'm using the square hammer lugs with original frame setup. I've tried spacing the timing out more without success but I'll play with it some more and see if there's a sweet spot.

[Fubarius]

Seems like a timing rod adjustment on the 3-way. It's activating the ram too early in the forward trigger stroke. Assuming a threaded timing rod (on that era of cocker, a pretty good bet), loosen the back set screw, turn the collar in one full turn, and retighten the set screw. Though that might be too much, but a half turn sometimes puts the set screws in a place you can't reach.

Always go only one full turn at a time, and keep track, incase it's making things worse and you need to get back to where you started.

A few other adjustments can cause the issues you're having. It's not so much the hammer slipping, but being too far forward when the ram starts to move forward. Cocking rod length for example. Or sometimes even pump arm length.

[heit1_32]

Winner! You and Beardedworks seem to have had it. I was able to adjust timing to find a sweet spot that works great. Now I'm gonna dig into cocking rod length and pump arm length for this trilogy that's having similar issues. Someone else shared this great resource that I hadn't seen before: https://www.mcarterbrown.com/forum/p...roubleshooting

[JohnB]

Google or search this site Ravi’s autococker mcarterbrown and that will take you to the tech page for cockers

[heit1_32]

Thanks! Fantastic resource! I've not paid attention to cocking rod length to be honest. Gonna give that a couple read throughs!

[Chemical-x.....ahain]

I got my copy off warpig and lost it at some point, thankfully it'd been saved and brought here. I stand by that its the best and most boiled down tuning guide. I recommend it all the time.

[BrendanB]

prob need to come down with ur lug a 1/4 turn, may have to move timing collar a hair longer since it works on full stroke, but not on short stroke.

[Cdn_Cuda]

I had a similar issue with my Fishbone Cocker. As it turns out it was a spring in the trigger frame that was the issue. Swapped the spring out of the frame and things worked better.

[heit1_32]

YES! This is what I discovered on the trilogy last night! Someone had put an aftermarket sear spring in which was super light. I replaced it with a heavier sear spring and suddenly the issues went away. 🤯 it's crazy how many different things issues can be caused by! I love the thrill of finally figuring out the problem though! 🙂

[JohnB]

That feeling of being running around your house at 9 or 10 pm yelling I did it after hours of tinkering. Almost makes you feel genius level for a second. Lol.

[Cdn_Cuda]

It is always nice finding a solution to a problem and MCB is amazing at helping find a solution to nagging problems. They've saved my butt many a time, so happy to pay it forward!