Shilen Bolts with Adj firing pins

[SFGUY]

I have a Shilen action (BP-S model) and it has an usual firing pin arrangement which is very interesting. Rather than a pin to hold the pin in the shroud it has a threaded end on the firing pin and uses a set screw to fix in place. I believe it is a left handed thread. Loosen the set screw and rotate the pin and it will lengthen or or shorten it a few thousandths. I developed some light strikes and discovered this.

Anyone else seen one of these? Ed Shilen sure knew what he was doing back then!

 

[lloydx2]

Some of the Superior Shooting Systems (Tubb) firing pin kits
with cocking piece came with threaded pins so you could set it for proper pin fall and timing. You drilled and pinned the cocking piece
to the shaft after adjustment. No set screws.

 

[SF-Guy]

Some of the Superior Shooting Systems (Tubb) firing pin kits
with cocking piece came with threaded pins so you could set it for proper pin fall and timing. You drilled and pinned the cocking piece
to the shaft after adjustment. No set screws.

Yes it is a fascinating arrangement and now that I am fully familiar I really like it! Too bad Shilen does not make any parts or springs. I will have to make what I need from here on.
When the set screw is loosened I can rotate the pin CW or CCW and tighten the spring tension. This does shorten the overall length but since the tapered pin matches the internal contour of the firing pin channel in the bolt, the pin protrusion is exactly the same. I was getting some light strikes and tightened the pin spring and solved the problem.

 

[jepp2]

Same way Sako (L461 models for sure) and Cooper does it. Lets you set the firing pin protrusion.