Gunsmithing Bench Rest Cocking Piece for R700

[mdesign]

I saw on the PTG website that they offer a "bench rest" cocking piece for the 700 actions. It appears that the stop has has been moved back .030 so I'm thinking to goal is to reduce lock time and the force of the impact of the firing pin slamming home and potentially disrupting the sight picture. Is this a benefit and if so, why not move the stop back .100 assuming there would still be enough force to fire the primer? Anyone ever tested how little force is needed to fire primers?

 

[Aeon1]

Kiff produced these in response to a bunch of guys quite a few years back that were grinding/shortening their own cocking pieces and others asked Kiff to make some up. The whole purpose as I recall was to improve the feel of the bolt closing. If you shorten the cocking piece the trigger/cocking piece to locking lug hand off is smoothed out. You eliminate or almost eliminate that little bump (aka cock on close) when dropping the bolt handle into battery. The downside is you lose pin fall (as you surmised) which many people have found to produce ignition problems. Others have never had an issue but many have with reducing pin fall. Look around and see how many have had ignition issues with the Timney 510. It was never intended to improve lock time and if you ask Kiff he never knew what the purpose was just that people wanted them.

Another note: Some bench rest competitors have moved their trigger hangers on the actions to do the same thing but many found it to be detrimental due to inconsistent ignition. The idea was a smoother bolt operation would disturb the rifle in the bags less.

 

[my human host]

It's all about speed with the br guys. The less you disturb the rifle manipulating the bolt, the easier it is to get your rounds off before conditions change.

 

[mdesign]

Thanks - figured there was a reason behind the design. Got my old 700 out and was looking at the how the cocking piece cycles when the bolt closes, .030 might make it feel very different.