Timing the ignition on a Bighorn TL3

[Alex Wheeler]

I have a customer that likes to run these actions in BR and F open. Overall they are a pretty decent action, but are really designed for a different purpose. Very shallow cocking cams make them open very easy but even with considerable cock on close they dont have much firing pin fall. This one had .203" with .025" of cock on close. Maybe not a bad setup for PRS but we do like them timed for Br and F open. So these do require cutting the cocking cam helix, picking up the threads on the firing pin and extending them, and machining the cocking piece. They end up with almost .260" of pin fall without any cock on close and still open nice. They do a pretty good job with the coatings on these, so they end up pretty nice. Extractors need a little work to get smooth on a single shot as well since its kind of a controlled round feed. Just something that may be of interest to some. No, Im not looking for a bunch of these to time LOL.

 

[boltfluter]

Very interesting Alex! Nice to know it is an option on these nice actions. I have a TL2 on a hunting rifle at the moment. As accurate as anything I have ever owned.
Paul

 

[Hal]

Alex

Thanks for posing pictures . It's always interesting to see what is done to fine tune actions.

Hal

 

[JFrank]

I have a customer that likes to run these actions in BR and F open. Overall they are a pretty decent action, but are really designed for a different purpose. Very shallow cocking cams make them open very easy but even with considerable cock on close they dont have much firing pin fall. This one had .203" with .025" of cock on close. Maybe not a bad setup for PRS but we do like them timed for Br and F open. So these do require cutting the cocking cam helix, picking up the threads on the firing pin and extending them, and machining the cocking piece. They end up with almost .260" of pin fall without any cock on close and still open nice. They do a pretty good job with the coatings on these, so they end up pretty nice. Extractors need a little work to get smooth on a single shot as well since its kind of a controlled round feed. Just something that may be of interest to some. No, Im not looking for a bunch of these to time LOL.
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Speaking of action timing, we need to chat.

 

[GoferDog]

Thanks for the photos, literally speaks a thousand words to those of us without the first hand knowledge!

 

[rwj]

Speaking of action timing, we need to chat.

Being merely a shooter with limited knowledge of smithing, what does “timing” an action involve?

 

[Carl S]

Very interesting Alex! Nice to know it is an option on these nice actions. I have a TL2 on a hunting rifle at the moment. As accurate as anything I have ever owned.
Paul

Excellent actions and I found they head space (TL3)the same.

 

[BoydAllen]

I have an older one with a threaded shroud that has plenty of pin fall and .015 cock on close. The shroud threads are fine and a very close fit. Since it is left bolt, the shroud is pulled into the bolt (RH shroud threads) as the handle is brought down. At the bottom there is no real gap between bolt and shroud.

 

[G7BC]

They offer push feed style bolt heads for these also. Just order the diameter you want and put "push feed" in the order notes. Really smoothed out single feeding for me with the bolt head not trying to capture the round.

 

[Alex Wheeler]

They offer push feed style bolt heads for these also. Just order the diameter you want and put "push feed" in the order notes. Really smoothed out single feeding for me with the bolt head not trying to capture the round.

Thats good info. After you rework the control feed it does close very well, just some polishing. But the push feed would be the way to go.