Remington 700 Cocking Piece pin broke

[VA_XTC_Shooter]

The cocking piece pin snapped on me this week during a match. Made the rifle like shooting a flintlock with a delayed ignition...no bueno for shooting offhand.

At first I thought the B&A trigger got dirty and was the cause until I disassembled the firing pin and the cocking piece pin fell out as two pins.

What causes cocking piece pins to break? Anything I can do preventative on? Or should I just replace every 5K rounds?

 

[Walt Krafft]

My first guess is the cocking piece is bottoming out in the slot when the gun is fired.

 

[VA_XTC_Shooter]

Would it be bottoming out because the firing pin spring is not as strong as it was new?

 

[BoydAllen]

Would it be bottoming out because the firing pin spring is not as strong as it was new?

No

 

[VA_XTC_Shooter]

No

what would be the cause/fix if it is bottoming out?

 

[Walt Krafft]

Need a lot more info. Rem 700 action, all factory parts? Any modifications to them? Before replacing the pin, measure the firing pin protrusion. Now replace the pin, un-cock the bolt, re-measure the pin protrusion. Is it the same? Is the cocking piece bottomed out?

 

[BoydAllen]

what would be the cause/fix if it is bottoming out?

First of all, you need to examine the bolt with the firing pin in fired position to see if the cocking piece is in fact bottoming in the cocking cam notch. FYI the front of the firing pin flange that the front of the FP spring contacts is what is supposed to stop the firing pin's forward travel when dry firing. When firing a live round the primer serves this function, but in no case should the front of the cocking piece make contact with the bottom of the cocking cam notch. I am guessing that you have not spent much time examining your bolt and figuring out how it works. These are good things to be familiar with, but of course no one is born knowing them. Feel free to ask.

 

[DaveTooley]

I've seen pins break from the firing pin having a small gap between the pin and the seat inside the cocking piece. Happens sometimes with after market firing pins and hardened dowel pins.

 

[VA_XTC_Shooter]

Need a lot more info. Rem 700 action, all factory parts? Any modifications to them? Before replacing the pin, measure the firing pin protrusion. Now replace the pin, un-cock the bolt, re-measure the pin protrusion. Is it the same? Is the cocking piece bottomed out?

Rem 700 pattern - Pierce action in an Eliseo UMRS, no mods or aftermarket parts.

Will measure as mentioned this evening.

 

[AlNyhus]

As Dave Tooley mentioned, make sure that the back end of the firing pin seats hard against the inside recess of the cocking piece when the holes line up for the cross pin. -Al

 

[Walt Krafft]

Since it is a Pierce action, you should call him.

 

[VA_XTC_Shooter]

Firing pin protrusion = 0.064”
Firing pin fall = 0.261”

The cocking piece does NOT bottom out in the cocking ramp notch when I’m fired position.

I did notice the cocking piece in the fired position has a little play. The cocking piece appears to bottom out on the back of the firing pin when the pin hole is lined up. However, the cocking piece pin hole is 0.094” dia and the firing pin hole is 0.101”. So I think play is coming from that.

I measured a new firing pin I have and that hole is 0.096”.

I’m guessing over time the cocking piece retaining pin hole in the firing pin has enlarged creating more play and back and forth force on the retaining pin itself and it ultimately failed.

 

[VA_XTC_Shooter]

Pierce is replacing the firing pin.

 

[chasespaugh]

As Dave Tooley mentioned, make sure that the back end of the firing pin seats hard against the inside recess of the cocking piece when the holes line up for the cross pin. -Al

How do you make this tight when the holes line up? Mine are too tight in my opinion, mIne have holes that dont lineup cause end of pin is too long to allow lineup and require a lot of force to remove/install the 'roll pin'.