Rimx build wont fire

[702lineman]

I have a lefty rim x that i put together a while back and have been fighting it ever since.

It randomly will fire. It dents the case every time i pull the trigger, just wont set it off. Roughly 1 in 10 cycles of the bolt will go bang. I talked to Zehrmatt and they thought the firing pin may be dragging the sear.

I have tried several different types of ammo, and all are the same.

Rim x action
22 match jgs reamer
Timney 510 trigger
Manners t6a stock
Hawkins dbm


Is there any way to adjust the sear height on the timeny? Anything else i can check? Im open to suggestions

 

[702lineman]

 

[JBoomhauer]

How’s the chamfer from the barrel face to the chamber look?

 

[702lineman]

 

[702lineman]

There isnt really any chamfer on the back of the chamber

 

[JBoomhauer]

Ok that’s good, I’ll include a drawing and a photo.

The geometry of the .22 rim to anvil is basically two radiuses tangent to each other.

The rim-x is controlled so it holds the round to the bolt face. If the chamfer is too big you do not have a surface to act as an anvil against the firing pin. It will push the round forward and rob all the energy.

Might not be what’s going on with yours as a lot of reamers have a radius built in here to avoid this issue.

 

[Boxerglocker]

Did you measure the headspace? Will it go no go with the Zermatt supplied gauge? Have you tried a different trigger?

 

[BisSilent]

And what barrel are you running? A large part of this equation.

 

[jbell]

Just check trigger sear clearance, I bet it’s dragging on the cocking piece.

 

[jbell]

Which drastically reduces the inertia of the firing pin creating light strikes / FTF.

 

[grauhanen]

And what barrel are you running? A large part of this equation.

Why is the barrel manufacturer part of the equation?

 

[BisSilent]

Why is the barrel manufacturer part of the equation?

I'm new to all of this but isn't that who sets the headspace?

I think that would be more part of the equation than the stock and bottom metal?

 

[Zermatt Arms]

It's almost certainly related to the trigger. We can modify the cocking piece to create more clearance if that's not been done yet.

Thank you - Ray

 

[Criver600]

I'm new to all of this but isn't that who sets the headspace?

I think that would be more part of the equation than the stock and bottom metal?he

"I have a lefty rim x that i put together a while back and have been fighting it ever since."

Self-smithed, he fitted the barrel.

Either a headspace issue or sear height, Call Ray at Zermatt, I've heard they can grind a cocking piece to work with your trigger. I'm running a Bix & Andy Tac Sport Pro two stage. I measured the cocking piece on the rifle and ordered the correct height sear. No problems with ignition.

 

[JRSaechao2020]

you can adjust the firing pin protrusion for better ignition

 

[702lineman]

I put a bix and andy in it shortly after I posted this thread and has been flawless ever since.

 

[702lineman]

Those pin strikes are more than deep enough to make any 22lr go bang. It's not the trigger or firing pin or any related ignition parts. It's the barrel. That semi cone breech was not machined correctly.

Well, It has been flawless for several thousand rounds now

 

[obx22]

Could you please post pics of the case rim, where it meets the breechface? I get that your sear could slow the striker down to cause this, but I’m wondering if the chamber rim is the cause. The case rim needs that support to enable the correct crush speed to ignite the primer. As an example, I examined a chamber which had seen excessive dry firing to the point it peened the steel inwards seizing the cases. Rather than “ironing” the steel back in place, the owner had ground off the offending burr. There after, the gun would fail to fire most times, even though the case rims were deformed from the pin strikes.

 

[702lineman]

Could you please post pics of the case rim, where it meets the breechface? I get that your sear could slow the striker down to cause this, but I’m wondering if the chamber rim is the cause. The case rim needs that support to enable the correct crush speed to ignite the primer. As an example, I examined a chamber which had seen excessive dry firing to the point it peened the steel inwards seizing the cases. Rather than “ironing” the steel back in place, the owner had ground off the offending burr. There after, the gun would fail to fire most times, even though the case rims were deformed from the pin strikes.

I changed the trigger like was suggested by Zehrmatt(or grind the cocking piece was also offered) AND IT HAS BEEN FLAWLESS FOR SEVERAL THOUSAND ROUNDS!!!!!! There is nothing wrong with the breech face, or anything else. It has been an awesome firearm and I love shooting it, and have had ZERO issues!!!! Feeds and fires very reliability and is ridiculously accurate. Thank you everyone for the help.