Tubb Duo Firing Pin Springs

[reinert]

Surfing around gun cyberspace yesterday, I came across this two spring system offered by David Tubb, and thought it looked like a good upgrade on a firing pin spring in a bolt gun. Anyone use this? I tried the search engine here, but didn't get any results. So, I thought I'd run it by ya'll. Interesting how the bolt torque is eliminated on firing. Might not make a noticeable difference in a hunting situation, but then again...

Check it out... He had a shorter youtube version of the springs and installation, but it wouldn't come up for me. This one did.

www.youtube.com/watch?v=rzVnN_5Wp6c

 

[Picher]

Interesting, but I'd be more convinced if there was a demonstrated increase in accuracy.

I haven't noticed a dramatic decrease in spring strength in any of my Rem 700s, or even in the 60 year-old 721 I worked on recently.

JP

 

[reinert]

JP,
Agree for sure; interesting. The torque elimination thing I thought worth a chin scratch. Most of my hunting rifle "rest" shooting practice is over my day-pack once I have a load I've settled on. The torque thing, shooting over a day-pack, probably wouldn't make a difference at all in the field. Maybe load testing on a good bench rest set-up might/could, though (along with a decent trigger). Pure speculation here.

 

[Picher]

I did some checking with several Rem 700s I own. The amount of bolt movement on dry firing varied among them, but the newest .270 had the most movement, so it was chosen for an experiment.

My theory is that, when dry-firing, the rear head of the bolt hits the bottom of the bolt cocking ramp and, depending on bolt position, may hit a bit on the ramp, causing the bolt to rotate.

I inserted a sized and primed(only) case and "fired" it and there was no rotation, (the case fit loosely in the chamber, so case friction didn't seem to retard rotation).

Apparently, firing pin travel was limited by contacting the primer, hence the cocking ramp was not contacted by the head of the firing pin. Trying an empty case with a fired primer also didn't cause rotation, for the same reason.

My brief test may not be conclusive, but I'm convinced that there is minimal, near-zero bolt spring-induced torque when actually firing the rifle.

I probably won't be buying the Tubbs spring kit any time soon.

JP

 

[reinert]

Thanks for doing that little test of yours. I tried it, too. I have 2 LA 700s (both '06), and one SA (.223). I put a fired case with a spent primer in both my LAs, and didn't see any kind of bolt movement at all on firing. My SA didn't really move much (if any that I could really notice) with an empty chamber, nor did it with the case/spent primer as with both LAs on firing. I believe I'll save my $$ and pass on the duo-spring, too.

I can only imagine a competitor like David Tubb has found fine tuning applications to enhance his shooting/rifles to the utmost. That two-spring addition on a competition rifle would be just one more factor to cancel out on the accuracy quest. My hunting rifles are o.k. as they are. Still, I found it an interesting video from a top rifle champion, nonetheless.