Cocking slide & light strikes

[Bill Graham]

Could intermittent light strikes be caused by a clocking slide that is binding as it articulates?

Thanks.

[Bill Graham]

Guess not, based on lack of comments. The reason I was thinking cocking slide is because of it interacting with the hammers, thinking it could cause a short stroke when cocking.

Second question, aside from weak springs, deep chamber cuts and/or thin rims, what else could be likely?

Thanks!

[mark beasland]

Crud

[Bill Graham]

Gave it another cycle through the ulstrasonic. Maybe the crud will get out of the way. I've also gotten great advice from Jason Barden on checking pin protrusion measurements, length of the sear, length of hammer struts, and maybe the mainspring. The thinking is that if it's not crud, it would be one of those components as the likely culprit. So far the pin protrusion is .0056', and the sears are 2.5" in overall length, which are within normal ranges. The shell cuts are acceptible too.

[jolly bill]

. . . So far the pin protrusion is .0056', and the sears are 2.5" in overall length, which are within normal ranges. The shell cuts are acceptible too.

I suspect you meant to type 0.056" as the measurement for your firing pin protrusion.

I have previously measured the firing pin protrusion on my Sterlingworth Pin gun and they measure 0.061" and 0.062" for right and left barrel. Shoots consistently with no problems.

I have an early A grade 12 gauge and depending on what primers (Winchester) I use in my reloads, the gun is a little hard to open after firing both barrels. Both firing pins extend 0.072" and I suspect engage the primer deeper, hence, difficulty in opening after firing both barrels. If I use Remingtom primers which seem to be harder, no problem opening.

This may not have anything to do with light strikes but thought I would at least offer this info.

Curious if it might be related to a particular brand of shell or primer.

Jolly

[Bill Graham]

. . . So far the pin protrusion is .0056', and the sears are 2.5" in overall length, which are within normal ranges. The shell cuts are acceptible too.

I suspect you meant to type 0.056" as the measurement for your firing pin protrusion.

Yes, I did. Thanks.

I've only shot Clever and Federal Target loads thus far. Both behaved similarly, and still only on the left. If the last, more lengthy, ultrasonic didn't fix it, I'll look at the springs and struts.

[bbman3]

You can shim the mainspring to make it stronger. Bobby

[Bill Graham]

I think it's been figured out. With a bit of anxiety, I removed the hammers and related parts. What I found was:

* Mainspring had irregular coil spacing and roughly ground ends
* Ejector mainspring follower (31) had a burr on the circumference of the hammer strut cup area that could restrict it's movement in its channel
* Ejector mainspring followers are split half the distrance of their length, and the split end pinches the ejector tabs that ride in the front of the receiver. The left side follower has a crack and had material had been built up. This build up increased the OD of the shaft, which certainly could have restricted the movement of the mainspring by reducing the space between it and the ID of the mainspring, retarding the power of the spring = light strike.

I don't know for certain if all this is the cause, but I did find a poorly finished part and a broken part, and they're being changed. I've also cleaned out the chanels the mainsprings ride in with Kroil and a brass bore brush for a .380.

If all goes well, I'll get the hammers back in without ruining something, or bleeding, and my wife will have a consistently firing gun for the Southern next week.

[Jim Cloninger]

Mr. Graham, You are becoming a very good smith in dealing with your Foxes! Keep it up. Jim

[Bill Graham]

Mr. Graham, You are becoming a very good smith in dealing with your Foxes! Keep it up. Jim

Thank you, Mr. Cloninger. I like to learn, and hope to stay humble as I do. I see spending this time as paying "tuition". Thank you all for being patient with the student.

[Bill Graham]

Update:

Ejector mainspring followers have been dressed, polished, and installed with a new pair of mainsprings. I also needed to polish up the edges of the ejector trip blades, which were binding a little. Thus far with dry firing, the triggers feel the same and the both sides sound the same as well. All is much more smooth. Additionally, both barrel eject empty hulls the same distance and with authority. I "feel" like the problem is solved, but that certainly could be wishful thinking.

As soon as I can test fire a box through it, with 100% success, I'll claim victory. Should be today or tomorrow for that.

Interestingly some of what I've been struggling with is in the latest newsletter: Volume nine, Issue 1.

[Bill Graham]

Update part 2:

Clever factory target loads. Pulled the triggers 27 times, gun fired 25 times. One light strike with the left side, and one rear trigger that didn't reset and was dead, towards the end of the box. I want to call it fixed, but I suppose another box would be in order. If it's not the same or better with another box, I guess Mrs. will shoot our sons Stevens 311A 20ga. Not what was hoped for, but better than not going bang 100% of the time.

Hopefully all of this helps someone sort a problem of their own down the road.

[mike campbell]

It may have occurred to you, but the other half of the "light strike" equation is primer seating depth. Federal promo ammo is especially prone to deep primers which may work fine in Bubba's gun but not in mine. I've no experience with Clever ammo.

Sometimes, striking the same shell with the same pin will set it off. If that happens, the jury is still out....if it fails to fire on a second strike, trying it in the second barrel is an option. If it fails to fire in the second barrel after 2 failures in the first, seems pretty obvious the shell is at fault. If it fails twice in the first barrel and goes bang in the second, that implicates the gun.

In any event, before it drives you to distraction, consider trying a third brand of ammo.

[Bill Graham]

The problem was fixed with a new pair of hammer springs, ejector hammer spring guide rods, and some polishing of the guide rods. One of the original guide rods had been broken and soldered back together, and there was a significant burr on it that would impede the movement of the spring, thereby reducing it's power and causing a light strike.