CZ 455 Installing DIP Sear replacement on trigger

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CZ 455 Installing DIP Sear replacement on trigger

Post by Rod_outbak » 12 Dec 2018, 6:35 pm

[I hope this helps someone else....]

Finally got around to replacing the factory (non-adjust.) sear on my CZ 455 Stainless Synthetic.
DIP adjustable sear replacement for the CZ 455(Through Delta Tactical).

I hadnt realized how BIG a PITA the detent ball was!

[Caught up on the joy of it when reading half a dozen forums about OTHER people having just as much frustration...made me feel a bit better.]

When the trigger assembly is installed, the sear has a spring that faces upwards & forward, and has a detent ball(~5mm dia) on the very top of it.
When the trigger is in place, the detent ball looks to rest against the receiver; just behind the mag-well mount.
In the new sear, there is a tiny hole at the top of the recess where the spring sits, and it is to retain the spring and ball during re-assembly.
[The folks at DIP instruct you to remove the mounting pins while the trigger assembly is inside a plastic bag; I can see why... I can also appreciate why they send a spare detent ball...]

Getting the old sear apart isnt a problem; putting the new one in is a PITA!!
[Likely even worse if you decided to re-install the old hole to retain the spring...]

During the assembly, you are expected to force a small spring back down into a hole, and then push it even further down with the ball on top, and then slide a pin in to hold it there until you can install the front pin. EASY, if you have 4 hands, microscopic vision, a missile containment shield, and a LOT of patience.

After nearly losing BOTH detent balls around the kitchen at speed, and much cursing, I ended up with the following solution:

A small block of Marineply to work on.
A big pair of vise-grips, to hold the new sear at the right angle.
A .30 cal flannel patch, to protect the sear from the jaws of the vise-grips.
A 1/4"-drive T15 or T20 security TorX bit, to use to push the detent ball down against the spring into the hole.
A 'Rapid' 9/14 heavy-duty staple; bent straight to use as my retaining pin.
An LED lantern to provide LOTS of light...

Locking the vise-grip onto the sear, I hung the sear over the side of the Marineply, which allowed the spring recess to be about vertical.
When I'm applying force, it will be straight down, which makes life easier.
Drop the spring into the recess, and then carefully place the ball on top.
DIP recommend a dab of grease on the top of the spring to retain the ball, but I didnt find it helped all that much...
The security TORX bit has a small hole in the tip, which helps stop the ball from vanishing at speed, when you start to push down.
I found keeping my fingers around the ball as I started applying pressure, meant I didnt have a vanishment at this stage.
[Vanishments are usually followed by a faint tinkle of a ball landing somewhere unknown, and quickly followed by a "Phukken Phukken" attack...]

Initially, I tried using a small paperclip to retain the ball/spring, but found it just wouldnt work.
EVENTUALLY, and after a few 'Lost Ball Searchings', and accompanied cursings, I hit upon using a 'Rapid' 9/14 staple from a hand heavy-duty staple gun, and found it was enough to keep everything in place long enough to re-assemble. I think because the staple is flat, it was a bit easier to slide in far enough to retain the ball/spring.
Also note you dont need the staple to go right across to the other hole; just in there enough to hold the spring/ball in for assembly(another failed assumption I made to start with)
However, until I was ready to pull the staple out to release the ball/spring, I had a flannel patch wrapped around the sear, to prevent further vanishment (and cursing).

One you get the front trigger-attachment pin back in, you can pull the staple out, and everything else is easy to resolve.

From this point on, it's quite simple to follow the remaining instructions DIP supplied.
Tiny allen key to adjust sear to your preference, test repeatedly that it's not too light, and then a tiny dab of Loctite to set it in place.
Put the rifle back into the stock, torque it down(~27 In Lbs), and give it all a good testing.
I've tried the safety, tried thumping the butt onto the table while cocked, and tried closing the bolt hard & fast, and none have caused it to fire, aside from when I pulled the trigger.
Trigger feels REALLY good, but not likely to give it the acid test until tomorrow morning.
I might also try out and see if the trigger gauge can tell me what weight I've got on it.
I left the (previously installed) Lowey sleeve on the trigger to remove creep; they seem to work pretty well together.

I also installed a DIP extended mag release at the same time. Metal instead of the factory plastic. A little bit fiddly getting the spring into position to re-assemble, but nothing compared to the poxed detent ball on the trigger. New mag release is slightly longer, and feels slightly easier to use.

All good. I hope this helps others.
Sharing the extreme love with cats in Outback QLD
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Re: CZ 455 Installing DIP Sear replacement on trigger

Post by Wm.Traynor » 12 Dec 2018, 7:36 pm

Commiserations Rod. I know from bitter experience just what a pig that job is.
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Re: CZ 455 Installing DIP Sear replacement on trigger

Post by Cooper » 26 Dec 2018, 2:30 pm

Does sound like a prick job Rod. I can live with the factory trigger on my Cz455. But I can see the advantages of having an adjustable sear. My cz452 on other hand needed some work. I installed Yo-Dave trigger Spring kit about 12 months ago. But I mistaking put the smallest shim (blue) when I should have probably started with the thickest shim (red). The blue shim was still an improvement. But it still had a little bit of creep.

I installed the red shim today and it is just about prefect for me.
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Re: CZ 455 Installing DIP Sear replacement on trigger

Post by Rod_outbak » 26 Dec 2018, 8:46 pm


Now that I understand how to do it next time around, it shouldnt be anywhere near as hard to repeat(if needed).
But I wont be upset if I dont have to ever pull that sear out again!

Elder brother was using the CZ 455 last week. He initially commented that the trigger was very light, but after a half-dozen rounds, he was hitting targets at ~100 metres from a rest easily(.17HMR).
I'm very happy with it. I've got the middle shim from the Lowey kit(same as the Yo-Dave?) in my 455, and it seems to take almost all of the creep out.
I think the trigger on my CZ 455 is now better than I need, and aside from the frustrating session installing the sear, the pain has been worth it.
It's turned out to be a really versatile little rifle, and perfect for what I wanted. I'm still waiting for the .22LR barrel, but I'm in no hurry.
Sharing the extreme love with cats in Outback QLD
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