- Nov 19, 2007
Gunsmith (action maker) is asking if I prefer neutral or slight cock on close. What would be the advantages or disadvantages of either for a long range hunting rifle.
With cock on close there is a hitch in the closing of the bolt, where you have to forcefully push the handle down past the “speed bump” as it cocks the firing pin more. With no cock on close the bolt handle evenly falls as you guide/lightly press it down. It helps to do it with just a single finger. My tikka for example goes part the way and then hits a bump and I force it over and it closes. My defiance Alex Wheeler timed shuts like I’m pressing a knife through warm butter.I'd love a good description of both because I have never heard those two options. Always learning something
Thanks for the description. I guess my question was more "what does it look like regarding lug/lug abatements for each". Are the abatements just barely fully engaged on the "perfectly timed"?I’ve seen some people prefer a slight cock on close with the concept being I believe that they can make opening lighter and rely on some of the closing cocking for full pin travel.
personally, I can’t stand it(cock on close) I don’t want another custom action that’s timed (or not timed) for cock on close because I find it extremely disruptive and annoying and always feels like an uncomfortable hitch during closing. However I would rather have an untimed/COC action than one timed for no cock on close with poor/insuffficient pin fall because the smith didn’t check firing pin travel before filing the cocking piece
I know Jim Borden mentioned he will time stuff either neutral handoff (0%) or a bit of close depending on what the customer wants as lots of prs guys like a lighter opening feel and don’t care about COC
With cock on close there is a hitch in the closing of the bolt, where you have to forcefully push the handle down past the “speed bump” as it cocks the firing pin more. With no cock on close the bolt handle evenly falls as you guide/lightly press it down. It helps to do it with just a single finger. My tikka for example goes part the way and then hits a bump and I force it over and it closes. My defiance Alex Wheeler timed shuts like I’m pressing a knife through warm butter.
for tactical stuff, high energy bolt cycling I rarely notice it. I run the tikka hard and put it up wet. While shooting quickly it I rarely notice the hitch on closing, but it’s there and it annoys me at times. If I could chose for it to not be there I would.
I’m not sure what you mean, I don’t know the technical aspects of the geometry but if I understand correctly the difference is just when and how the cocking peace is handed of to the trigger sear.Thanks for the description. I guess my question was more "what does it look like regarding lug/lug abatements for each". Are the abatements just barely fully engaged on the "perfectly timed"?
Thanks Shep. Should have known to just ask you Still a bit cloudy, but I'll read it again to make sure I get it. Again, thanksCock on close actions like a 96 Mauser the sear catches well before you can close the bolt handle. Which means you need to push the bolt forward against the spring to close the bolt. On modern factory rifle actions the same thing is happening but at a much reduced distance. Model 70 and rem 700 are actually considered cock on opening actions but do have some more cocking that happens as you close your bolt. The sear engages just as the lugs on the bolt hit the ramps in the action. As the bolt is closed it moves forward on these ramps and the cocking piece stays stationary. This is why it cocks more on close. But on a timed br action or any action really the sear engages when the lugs are at the end of the ramp and allow the bolt to close with out further cocking of the firing pin. On actions that are timed a little too far the bolt will almost close itself and you will see the cocking piece move slightly forward as you close it. On actions with trigger hangers you can move the trigger forward to remove the cock on close feeling but you can only go so far because the distance you move the trigger forward has to be subtracted from your pin fall. To little pin fall will sure ruin accuracy. On a rem 700 you can grind back the cocking piece engagement surface to help some but again it will reduce your pin fall. To get this pin fall back requires machining many other parts like your firing pin tip and stop and the cocking piece and the cam ramp in the bolt. To me it’s not worth the effort on factory actions. If you want that kind of timing go custom. I know Bordin will time your trigger for you if you send it to him or buy a trigger from him and Wheeler does timing on some actions. Like has been said if your running your action fast it’s not real noticeable but if you are looking through the x hairs and close the bolt it is going to move. On a well timed action you can be on a pack for a rest and put a round in the chamber and close the bolt and the gun will stay on target. These timed actions would benefit hunters that chamber a round before firing as opposed to hunters who hunt with one in the chamber. So your hunting style and geographic area you hunt would help make up your mind.
If it’s no cost difference I would go perfectly timed every time. Just know on factory actions there will be a lot more cost to achieve this properly.