Remington 700 Firing pin drag

[tonyben]

My Remington 700 build is coming along nicely but I noticed that with a stripped bolt, it slides and locks freely with no resistance. With the firing pin installed, I can feel resistance as the firing pin tail drags on the side as it passes through the slot in the tang of the receiver.

Is this typical or is this something that people typically fix on their receivers? Do you widen the slot a little? Stone down the firing pin tail?

Thanks,

Tony.

 

[DaveTooley]

How does it line up when in the cocked position. That's all that matters. Even then friction on the side of the cocking piece would minimal. Bushing the firing pin hole and modifying the firing pin to stay supported when cocked is far more important.
Once upon a time I reamed and polished the interior of the bolt and made a bushing to fit in front of the firing pin spring to maintain alignment. Don't know that it helped but it didn't hurt.

 

[Will Henry]

Like Dave said, the important thing is whether or not the striker drags anywhere when the rifle is fired. When the striker is in the fired position, it should not contact anywhere in the notch. Not on the cam and not on the straight side. Remove the striker assy and check to make sure the pin isn't dragging in the bolt head. WH

 

[DaveTooley]

Like Dave said, the important thing is whether or not the striker drags anywhere when the rifle is fired. When the striker is in the fired position, it should not contact anywhere in the notch. Not on the cam and not on the straight side. Remove the striker assy and check to make sure the pin isn't dragging in the bolt head. WH

I'll bet there is a shiny mark at the 6 o'clock position on the tapered section.

 

[rwj]

One would think that the slot width in the firing pin shroud would be narrower than in the action to avoid such contact?

 

[DaveTooley]

One would think that the slot width in the firing pin shroud would be narrower than in the action to avoid such contact?

Too many variables with all the parts involved.

 

[tonyben]

This is where it hangs up...

It breaks free here...

This is the rub mark on the receiver...

Corresponding rub mark on the firing pin tail...

Second bind point...

Also noticing these two surfaces are not on the same plane...

I checked four other Remington 700 rifles I have here and none of them have the drag.

If I could identify an actual root cause, it would be that the notch in the bolt body that the firing pin tail detents to is off by a couple of degrees. If it was located a couple of degrees more clockwise, the drag wouldn't happen.

**Edit** I took the firing pin from another action and put it in this one and the binding is gone. Upon further observation, it seems the firing pin channel at the tang might be milled just slightly off center. If you look at the action screw, the hole isn't centered on the firing pin tail channel.

It looks like I have a case of tolerance stacking. I put my firing pin in the other rifle and it doesn't hang up at all.

It looks like I just need to take a skim pass on the channel and open it up maybe 0.005"

Tony.

 

[DaveTooley]

So now what?

 

[LVLAaron]

 

[ShtrRdy]

@tonyben -- that's interesting. Thanks for the excellent pictures.

 

[ebb]

Leave the firing pins swapped????

 

[AlNyhus]

I'd start by tweaking the cocking piece.

Good shootin' -Al

 

[STS]

I’ll place bet that the action screws are not perpendicular to the action rails. It’s more common than one would think and easy to see with the action set up on a flat surface and the guard screws in their hole. That would lead you to believe that the cocking piece slot is off center..

 

[tonyben]

Leave the firing pins swapped????

I was going to do this and make sure that firing pin protrusion wasn't out of spec. I checked firing pin protrusion with my USGI firing pin GO/NO-GO gauge and the firing pin from my original bolt fails in both bolt bodies. It protrudes past the 0.060" maximum protrusion. I checked my original FP and it protrudes 0.077" from the bolt face.

Tony.

 

[ebb]

Yea, I never thought of that! It is important!!! I had one that was in a factory bolt and was put into a PGT bolt and was too short, lots of hang fires. The picture of the tang sure looks like the slot is misaligned with the hole. I just looked at 2 of mine and the older short action looks as if it is misaligned also and in the same direction as yours. The newer SS magnum action looks like it is closer to center than the picture you posted and my SA. The SS looks like it was a hex hole and was drilled round and the points of the hex still show.

 

[WSnyder]

I’ll place bet that the action screws are not perpendicular to the action rails. It’s more common than one would think and easy to see with the action set up on a flat surface and the guard screws in their hole. That would lead you to believe that the cocking piece slot is off center..

Pretty common. I have one here that has the action screws in one plane, trigger in another and the base screws on a third. Those three all point in different directions. How did they screw this one up that bad???

 

[AlNyhus]

@tonyben, how much bolt-to-receiver clearance do you have at the back end of the bolt? -Al

 

[tonyben]

@tonyben, how much bolt-to-receiver clearance do you have at the back end of the bolt? -Al

I can fit a shim stack 0.014" thick between the front of the bolt handle and the receiver. Is that the clearance you're asking about?

Also, I was measuring FP protrusion before with the bolt locked in the receiver and measuring from the face. This morning, I pulled the cocking piece back and rotated it to the firing position and placed the bolt body in a vise to get a better measurement and this morning I measured the actual firing pin protrusion at 0.071".

Is this still too far? I might polish the firing pin tip and see if I can take off 0.002 and get it below 0.070".

Tony.

 

[AlNyhus]

Tony, I was asking about the radial clearance....bolt body diameter versus raceway diameter. -Al

 

[Edd]

Also, I was measuring FP protrusion before with the bolt locked in the receiver and measuring from the face. This morning, I pulled the cocking piece back and rotated it to the firing position and placed the bolt body in a vise to get a better measurement and this morning I measured the actual firing pin protrusion at 0.071".

Is this still too far? I might polish the firing pin tip and see if I can take off 0.002 and get it below 0.070".

Tony.

Why wouldn't you grind ~.015" off of it?