Gunsmith Input ?

[Liven The Dream]

Remington 700 SA .308 Bolt Face Custom Bolt small Firing Pin . Used in a F/Class Rifle

Had weak sound when Firing ?
I pulled the Bolt down to find a broken cross Pin and loose Cooking Piece.
The Threads on the Shroud like razors !
The Firing Pin is steel Fluted , Cooking Piece and Shroud Aluminum ??
The Cross Pin Broken not in the Middle ? about 60/40 ?

I have ordered New SS and steel Parts .
I am also contacting the Company That Sold the Action and did the work ?

Any input for this Problem would be appreciated ,

 

[DaveTooley]

Your cocking piece is steel. Sometimes there is a gap between the end of the firing pin and the cocking piece. Sometimes it doesn't take much to break those pins. If you dry fire a lot that can break the cross pin if there's a gap.

 

[Liven The Dream]

Your cocking piece is steel. Sometimes there is a gap between the end of the firing pin and the cocking piece. Sometimes it doesn't take much to break those pins. If you dry fire a lot that can break the cross pin if there's a gap.

Thanks
The cocking piece was not steel

 

[gunsandgunsmithing]

Thanks
The cocking piece was not steel

I've seen plenty of aluminum bolt shrouds, but never an aluminum cocking piece. Are we on the same page, terminology wise?

With the bolt in the fired condition, is there a gap between the cocking piece and the bottom of the cocking ramp of the bolt?

 

[Liven The Dream]

I've seen plenty of aluminum bolt shrouds, but never an aluminum cocking piece. Are we on the same page, terminology wise?

With the bolt in the fired condition, is there a gap between the cocking piece and the bottom of the cocking ramp of the bolt?

sorry Cocking Piece looks to be investment Casting ?

I am sending the Parts back to the Builder of the Action ??
I have ordered New parts , Delevery not for week or so.

 

[linebaugh]

Just had one go down on a buddy at a match 2 weeks ago. Same thing. Probably some dry fire that started the process but who knows. Was on an Alimo Precision action. Fix is straight forward... new pin.

 

[fyrewall]

If a part sticks to a magnet that part is steel. The investment cast process can be used for making steel parts followed by final precision shaping if needed.

 

[Dusty Stevens]

Buy a whole new replacement firing pin assy. They sell them to replace the J lock assemblies

 

[Liven The Dream]

I have all new parts on order ! As a complete unit ? Small firing pin .

The cocking piece had a lot or wear ( finish off ) on one side ? I am thinking low quality parts .

 

[Edd]

Your cocking piece is steel. Sometimes there is a gap between the end of the firing pin and the cocking piece. Sometimes it doesn't take much to break those pins. If you dry fire a lot that can break the cross pin if there's a gap.

Would you explain how a gap between the end of the firing pin and the cocking piece contributes to a broken pin?

 

[DaveTooley]

Every time the firing pin falls and then stops, the cocking piece impacts the cross pin instead of the end of the firing pin. The cross pins are hardened most of the time making them brittle.

 

[Alex Wheeler]

If the cross pin was broken, look for a groove inside the shroud where one side or both side may have backed out and dragged inside the shroud bore.

 

[Walt Krafft]

Every time the firing pin falls and then stops, the cocking piece impacts the cross pin instead of the end of the firing pin. The cross pins are hardened most of the time making them brittle.

Actually there should be a gap between the end of the cocking piece and the bolt notch in the fired condition. This means that the firing pin is stopping on its shoulder. If there is no gap it is stopping on the cocking piece which breaks the pin.

 

[DaveTooley]

Actually there should be a gap between the end of the cocking piece and the bolt notch in the fired condition. This means that the firing pin is stopping on its shoulder. If there is no gap it is stopping on the cocking piece which breaks the pin.

I'm referring to the gap at the end of the firing pin and the recess in the cocking piece. If there's a gap there the cross pin takes all the load when fired.

 

[Scott Harris]

It's pretty common to break the cross pin and the reason is as Dave Tooley states. I've used shim stock to fill that gap. Not a big fan of aluminum bolt shrouds because the cross pin can work out and gouge into the shroud...with adverse ignition effects. When it comes to the ignition system (shroud, cocking piece, firing pin), I think goood ole steel is the best solution.

 

[Liven The Dream]

It's pretty common to break the cross pin and the reason is as Dave Tooley states. I've used shim stock to fill that gap. Not a big fan of aluminum bolt shrouds because the cross pin can work out and gouge into the shroud...with adverse ignition effects. When it comes to the ignition system (shroud, cocking piece, firing pin), I think goood ole steel is the best solution.

When the parts get here a testing will be done .
Have shim stock .
Thanks

 

[BoydAllen]

A while back, working on a custom action that has a Remington configured cocking piece, while changing the spring, I noticed that the cross pin was bent and seemed to be made of inferior material, so I sacrificed a small drill bit of the proper diameter, using a smooth section of its shank. No problems since. Drill bits are a local hardware store item, and they are inexpensive in that size.

 

[Edd]

Every time the firing pin falls and then stops, the cocking piece impacts the cross pin instead of the end of the firing pin. The cross pins are hardened most of the time making them brittle.

That's interesting, I wouldn't have thought the inertia from something as light as the cocking piece moving such a short distance would break that pin.

Anyone ever put a larger pin in there?

 

[DaveTooley]

That's interesting, I wouldn't have thought the inertia from something as light as the cocking piece moving such a short distance would break that pin.

Anyone ever put a larger pin in there?

all the parts are hardened
99.99% of the time there's no problem