Cocking force and bolt movement

[1jonzmith]

There is a Gentleman on another forum named "Clark". He is a mechanical engineer by vocation. His postings and videos qualify him as the "go-to-guy" for preeminent professional Gunsmiths when they encounter a really sticky problem with mechanics. Clark uses measuring instruments that have the old timey round gauge/scales for the readout. Great for filming and demonstrating what he is talking about. As you might be able to tell, I found this man to be a very impressive fellow. In one of his vids he connected a 1/4 inch torque wrench to the bolt nut and measured the force needed to cock a rifle. WOW! FLASH! No more "seems to be better" or "broke in" or how many other subjective observations. Max inch pounds to cock his rifle was ????? Whatever it was. I bought that $270 dial readout torque wrench by SnapOn for not nearly any where near the new price and have set to measuring my bolt performance. Regretfully I didn't have the wrench when I sent the receiver off to SSS for a T&T job. But I can spit out numbers now. Problem is that the cocking ramp, that primary VILLEIN in the entire bolt operation, isn't the only part of a bolt cycle that I find offensively difficult/rough. I want to document the forces across the cocking and battery cycles that include all the little "flaws" in the design/finish of my gun.

Does anyone have the type of inch pound torque wrench I mentioned and a "stock" action that they can measure both lubricated and dry(as most are). I will be documenting the various "nodes of resistance" in both strokes. Following that I will address the cause of the resistance on my SS Target action and be able to quantify the results for my action. I think this will have a close relationship to other SS Target actions only. Might be very useful to others with any Savage 110 action, however. We could also use this data to measure the effectiveness of lubricants for the Savage.

So, is there another tinkerer with a SS Target action and access to a torque wrench that has the time? I can't imagine that the data collected will not be of interest to the Forum.

PM me or use jegrabe@gmail.com

Thank you,

John

[thomae]

:) We have our share of engineers on this forum as well. Sharpshooter comes to mind right away. Take a look at the following post and it may address some of your issues. It certainly shows that there is at least one person on this forum who tries to use a very serious and careful scientific method when attempting to determine what works better.

http://savageshooters.com/SavageForum/index.php/topic,30658.msg219952.html#msg219952

Do you have a link or links to the other thread(s) you reference so we can take a look at "Clark's" posts?

Also, (this is neither meant as a cheap shot, nor a slam, but rather a more precise technical vocabulary lesson) FWIW, the "measuring instruments that have the old timey round gauge/scales for the readout" are more generically known as "analog" and specifically as "dial" instruments. For example: a dial caliper:
http://www.gagewebsite.com/wp-content/uploads/2011/04/6-dial-caliper.jpg.

A dial indicator:
http://www.humboldtmfg.com/images/products/large/H-4460.jpg

[stangfish]

Analog instruments have their place, I have some digital stuff in my box...all with dead batteries.

[Blue Avenger]

Sharp shooter has done the work a time or two also. Here is something he wrote that I copied and pasted. It is a response to a "bolt lift kit" that was being tested so some of the response will not directly correspond to You.

http://savageshooters.com/SavageForum/index.php/topic,47731.0.html

[BobT]

I have the torque wrench you mention, alas no Savage target action. It sounds like an interesting project though.



Analog instruments have their place, I have some digital stuff in my box...all with dead batteries.


I only have one digital caliper, I use it to check case lengths. My work tools are all analog, dial or vernier. All the new "kids" they hire at work buy digital stuff, most of them don't have a clue how to use it!

[Blue Avenger]

LOL I'm old enough to use it and a clock with those stick things with no numbers, just chose not to when I can. :)

[justin1098]

I have a stock ss target action and a dial type inch pound torque wrench.

[Smokey262]

Some of us still have these too

http://www.verniercalipers.net/verniercaliper.jpg

[1jonzmith]

Sharp shooter has done the work a time or two also. Here is something he wrote that I copied and pasted. It is a response to a "bolt lift kit" that was being tested so some of the response will not directly correspond to You.

http://savageshooters.com/SavageForum/index.php/topic,47731.0.html


Blue,

I remember now that I have read SS post. It is a terricic post and a must read prior to reading what I will post eventually. The post by Clark is better only ion that it is a video and it gives you close ups of the dial while measuring. SS is a better post in that he gives more and better info. Engineer like.

Clark is a fixture over on the Mosin Nagant board.

Thanks all, John

Thank

[justin1098]

cocking force on my rifle, that is greased, is 21 and a half in/lbs when cycled slowly. Its 20 in/lbs cycled at normal speed.

[1jonzmith]

Justin,

Good for you! M y cocking force is 25 max with normal lube and oiling. It drops to 16 when I grease it. The difference is profound...in mine. I think you will see an equal improvement when we are done with this.

I owe you all a description of what I am doing and my objectives. As SS says "first step is telling us what your goal might be". In this case "My goal is to identify the cause of the required cocking and cycling force...firstly. That will result in a corrective action. Finally, measure the effectiveness of the corrections".

For a prelim: I have reduced the cocking force in my SS Target action from 25 inch pounds to 16 inch pounds with nothing more than the "proper grease" on the cocking ramp. More good news to come but I suspect, hunch, that 16 is as far as we can depress the max cocking force due to the need to compress the firing pin spring. BUT, there is just soo many other points in the cocking stroke where nodes of resistance are found that can be all but eliminated that the character of the Savage, mine at least, can be improved to the point that it won't be recognizable.

I will try to get the explanation of the procedures to collect the data....and I will use that word loosely. Validation and a grand finale will be up to SS and his likes.

John

[seanhagerty]

Pictures of where to grease and polish. We all throw terms around that some may not understand...(ME!!)

Sean

[fgw_in_fla]

I recall having to stand on the rifle & pull on the bolt handle with a cheater bar before I read some of Northland's informative posts. There's a few others here that have also provided good info on bolt lube & such but Jim's info stick's in my empty head for some reason....

At this time, after polishing & lubing I can cock the bolt with one finger without jarring the rifle around & knocking it off target.

It's amazing what a little lube will do for ya... :o


"Slippery" Frank in Fla.

[cwop]

i would sure like to see how this is accomplished!!!!

bob

[1jonzmith]

i would sure like to see how this is accomplished!!!!

bob


And you will Grasshopper....and you will. Can you also help? Can you lay hands on a inch pound analog dial torque meter? Analog lets you see the force you are dealing with and where and when it happens. Round dial redaouits have a "memory of the max torque applied and for reporting and documenting that is a very nice feature. Also not rare in the least. I have another post coming on the "how to" so you might want to wait till you do it. If you don't want to spend the $80 to buy a used Snap On inch pound wrench may I suggest that you have a auto parts store that will lend tools with a deposit. May shops/etail outlets around here do this so it isn't out of the ordinary. A rental would be $5.

Thanks for your interest.

John