Rem 700 bolt lift improvement

[Alex Wheeler]

My testing of springs with different rates shows there is no magic there. Compressed force is compressed force. A lower rate spring will maintain a more even force over its compression. Thats what is being sold. A high rate spring may range from 23lb in the cocked to 17lb. fired. So some would say we can lower the spring rate, compress it more and say go to 21lb cocked, but because of the design we still are at 19 in the fired. Total force over the travel is similar and bolt lift is reduced. This is very obvious in the Bat B vs Bat M spring designs.

 

[mike a]

you can see on the bolts pictured, the one on the left (Rem 700) the cocking piece notch is further away from the end of the cocking ramp (note the flat between the notch and the end of the ramp) than the bolt on the right (Pierce) that makes the cocking ramp on the left steeper which increases the bolt lift force, other factors I've found that helps decrease bolt lift is the surface finish as well as the surface hardness of the interacting parts, the bolt and cocking piece on the right have been nitrided, the harder surfaces glide easier over each other, if you decide to wade in and try re shaping your cocking ramp, be very careful, the water gets deep real fast

Very illuminating. No words could of explained that to me. I'm not a gunsmith but pretty handy. Clearly making a change like that is not a hand tool job. That is why I'd rather save more money and go custom. I'll never go back to factory again. Im sure the 700 is making a lot of money for Gunsmith's. Seems to me fools and there money easily separated. Mike

 

[Michael Huebner]

My testing of springs with different rates shows there is no magic there. Compressed force is compressed force. A lower rate spring will maintain a more even force over its compression. Thats what is being sold. A high rate spring may range from 23lb in the cocked to 17lb. fired. So some would say we can lower the spring rate, compress it more and say go to 21lb cocked, but because of the design we still are at 19 in the fired. Total force over the travel is similar and bolt lift is reduced. This is very obvious in the Bat B vs Bat M spring designs.

Alex,
You lost me at “A lower rate spring will maintain a more ‘even force’ over its compression.” How does a lighter single rate spring achieve this compared to a heavier single rate spring? Keeping in mind that the actual spring force = travel length x Spring k

Ok, so the BAT ‘Light’ spring for the DS,B etc actions must fall into your statement above, lighter spring rate compressed further = higher lbF

BAT Light Spring specs
Free Length = 6.69”
Outside Diameter = 0.401
Inner Diameter = 0.293
Wire Diameter = 0.054
No. Of Active Coils = 46
No. Of Coils = 48
Spring Rate k = 6.356lb/in
Installed (Action cocked) height = 3.2”
19.82lbF Max Force (Safe limit)
At loaded height of 3.2” = 22.18lbF

1. Can you explain to me how the spring can obtain the 22.18lbF?
And if this force can be achieved, how many times can the spring achieve this force?

2. So in your examples above with say a 21lb spring and it’s still 19 in the fired position are you saying it takes 2lb to cock the action.
And the 23lb spring - 17lb in fired so 6lb to cock action - Is this what you are suggesting? If not what are you meaning?

This is what I would like to know. It’s not a trick question(s) I genuinely would like it explained to me.

Can send me a message if you don’t want to reply here

Michael

 

[Alex Wheeler]

1. The light spring that comes in a model B does measure about 21.5lb in the cocked position and about 19 fired. Pretty close to the numbers you quoted.
2. I am talking about how much force a spring is loosing over the 1/4" of travel we use it for. A higher rate looses its force faster than a lower rate thats highly compressed. So Im saying we are adding 2lb of spring force when we compress the spring from fired to cocked position in the B example.

 

[carlsbad]

90% of the bolts I receive for bushing are inadequately greased. The threads should be well greased.

Some springs compress in a way that drags on the inside. If your spring is dragging, replace it with one that doesn't bulge when it compresses.

Heavy firing pin springs aren't needed. If you have an aftermarket heavy spring, go back to a lighter one. If you think you need one, something else is wrong.

I thread all the bolt knobs on Remingtons and put a longer bolt knob on. You don't have to use one the size of a hand grenade to get more leverage. Or when you adjust the timing, solder on a longer handle from hollands or PTG.

I also reduce the cocking detente as shown above.

Trigger timing doesn't affect bolt lift but it affect bolt cycling. a rifle with the cock on close reduced to .005" will cycle much more smoothly in the closed direction making it feel like less force is required. This is one of the things that makes a custom appear much smoother than a stock Remington 700.

If you want to go all the way to Dollar Shave Club smooth, then you can replace your bolt with an oversize aftermarket bolt and ream/lap the boltway. But that doesn't affect cocking force.

Jerry

 

[topclass2017]

stone the cocking ramp

Sounds like a middle ages battle cry..."Stone the Cocking Ramp!"

 

[Twdmar]

Something that I think perhaps has not been mentioned is that, in my opinion, you can over polish the cocking ramp. By this I mean, if its too smooth and I want to put a little grease on the ramp, the grease just gets wiped off when moving the bolt. I like to think that by only finishing with 400 grit there are some fine scratches that hold a little lube after the cocking ramp has been burnished a little by working the bolt.

 

[Michael Huebner]

1. The light spring that comes in a model B does measure about 21.5lb in the cocked position and about 19 fired. Pretty close to the numbers you quoted.
2. I am talking about how much force a spring is loosing over the 1/4" of travel we use it for. A higher rate looses its force faster than a lower rate thats highly compressed. So Im saying we are adding 2lb of spring force when we compress the spring from fired to cocked position in the B example.

Alex,

The spring spec I put in my post above is the BAT 'DS', 'B' light spring and I understand what you are saying with the heavier spring losing force quicker. The issue with the longer spring the manufacturers say is they are likely to have some set, so reduce length. Thats why they have a safe force limit and minimum installed length. If that light spring sets 1/2" then it loses about 2.5-3lb of force, which makes it marginal for ignition. It will be a 19 -16lb spring
The BAT Heavy Spring has the following Specs;
Free Length = 5.45”
Outside Diameter = 0.416
Inner Diameter = 0.294
Wire Diameter = 0.061
No. Of Active Coils = 41
No. Of Coils = 43
Spring Rate k = 10.84lb/in
27.3lbF Max Force (Safe limit)

At loaded (action cocked) height of 3.2” = 24.4lbF

So assuming .25 Fall, it is a 24.4lb in the cocked and 21.68 in the fired with nil issues regarding extra length causing potential set of spring and loss of spring force.

For comparison the Dwight Scott Tungsten weight and spring that I have is a 24.5lb Max Spring and is a 22.1 to 19.24 spring, no extra length etc, more like the BAT Heavy Spring in design

Do you find these extra long lighter springs become shorter after they are installed (They set like the manufacturers warn they will)?
How often are you changing these sprngs?

I will try both and see how it shoots and whether I notice the light long spring set and the extra 2lbs on the heavy spring when cycling the action. Also the heavy spring gains around an extra 8% impact energy over the lighter spring!

Cheers
Michael

 

[butchlambert]

Alex,

The spring spec I put in my post above is the BAT 'DS', 'B' light spring and I understand what you are saying with the heavier spring losing force quicker. The issue with the longer spring the manufacturers say is they are likely to have some set, so reduce length. Thats why they have a safe force limit and minimum installed length. If that light spring sets 1/2" then it loses about 2.5-3lb of force, which makes it marginal for ignition. It will be a 19 -16lb spring
The BAT Heavy Spring has the following Specs;
Free Length = 5.45”
Outside Diameter = 0.416
Inner Diameter = 0.294
Wire Diameter = 0.061
No. Of Active Coils = 41
No. Of Coils = 43
Spring Rate k = 10.84lb/in
27.3lbF Max Force (Safe limit)

At loaded (action cocked) height of 3.2” = 24.4lbF

So assuming .25 Fall, it is a 24.4lb in the cocked and 21.68 in the fired with nil issues regarding extra length causing potential set of spring and loss of spring force.

For comparison the Dwight Scott Tungsten weight and spring that I have is a 24.5lb Max Spring and is a 22.1 to 19.24 spring, no extra length etc, more like the BAT Heavy Spring in design

Do you find these extra long lighter springs become shorter after they are installed (They set like the manufacturers warn they will)?
How often are you changing these sprngs?

I will try both and see how it shoots and whether I notice the light long spring set and the extra 2lbs on the heavy spring when cycling the action. Also the heavy spring gains around an extra 8% impact energy over the lighter spring!

Cheers
Michael

Hey Michael, How are things down under?

 

[Alex Wheeler]

Alex,

The spring spec I put in my post above is the BAT 'DS', 'B' light spring and I understand what you are saying with the heavier spring losing force quicker. The issue with the longer spring the manufacturers say is they are likely to have some set, so reduce length. Thats why they have a safe force limit and minimum installed length. If that light spring sets 1/2" then it loses about 2.5-3lb of force, which makes it marginal for ignition. It will be a 19 -16lb spring
The BAT Heavy Spring has the following Specs;
Free Length = 5.45”
Outside Diameter = 0.416
Inner Diameter = 0.294
Wire Diameter = 0.061
No. Of Active Coils = 41
No. Of Coils = 43
Spring Rate k = 10.84lb/in
27.3lbF Max Force (Safe limit)

At loaded (action cocked) height of 3.2” = 24.4lbF

So assuming .25 Fall, it is a 24.4lb in the cocked and 21.68 in the fired with nil issues regarding extra length causing potential set of spring and loss of spring force.

For comparison the Dwight Scott Tungsten weight and spring that I have is a 24.5lb Max Spring and is a 22.1 to 19.24 spring, no extra length etc, more like the BAT Heavy Spring in design

Do you find these extra long lighter springs become shorter after they are installed (They set like the manufacturers warn they will)?
How often are you changing these sprngs?

I will try both and see how it shoots and whether I notice the light long spring set and the extra 2lbs on the heavy spring when cycling the action. Also the heavy spring gains around an extra 8% impact energy over the lighter spring!

Cheers
Michael

PM sent

 

[Michael Huebner]

Hey Michael, How are things down under?

Butch,
Going well. I have three boys now, 15 months, 3 1/2 and 5 1/2 which keep us busy.
Didn't get to Canada WBC as finances didnt allow. Maybe next time.

Hope to get to the USA again soon.

Hope all is well with you and your family

Michael

 

[Papa Charlie]

I still have my factory spring in my Rem 700 F-TR rifle after more than 3700 rounds. I haven't experienced any problems with it.
It has been suggested that I replace it. So I ordered a Wolff 28 lb, but after reading this I wonder if this was the best choice.
The only thing I can say about the stock spring is that when dry fired the impact does move the POA more than I care for.
What replacement would you recommend?

 

[Dusty Stevens]

I still have my factory spring in my Rem 700 F-TR rifle after more than 3700 rounds. I haven't experienced any problems with it.
It has been suggested that I replace it. So I ordered a Wolff 28 lb, but after reading this I wonder if this was the best choice.
The only thing I can say about the stock spring is that when dry fired the impact does move the POA more than I care for.
What replacement would you recommend?

If it moves now youll really hate the 28. Just put the factory replacement back in

 

[Papa Charlie]

If it moves now youll really hate the 28. Just put the factory replacement back in

But is there a better choice that will reduce that impact movement?

 

[Dusty Stevens]

But is there a better choice that will reduce that impact movement?

Proper action setup will eliminate it if its the bolt moving. If the bolt doesnt move its either your trigger or you. Its a pretty violent knock so sometimes “movement” is a relative term and different for different folks.

 

[BoydAllen]

I know that this is an old thread, but I reviewed it just now because it was linked to from a current one on bolt opening force. Dusty's post is probably about the motion that is seen of the cross hairs on the target when dry firing on an empty chamber. My reason for adding to this thread is that one time, years ago, I was looking at this and found that switching rear bags took the jiggle from slight to none.

 

[BoydAllen]

You need mass and speed. That comes with standard weight or heavier moving assemblies, and more than standard weight springs. Lighter springs equal less speed no matter what any salesman says or how good the bolt lift feels afterwards

Stiller once told me that there is no substitute for pin fall. Take as heavy a hammer as you can manage and hold it a half inch away from somthing and hit is as hard as you can, then do the same thing from a foot away. A smaller tip has a higher unit loading for the same pin weight, spring weight and pin fall. The force is more concentrated. The area of a .075 dia. circle being 46% larger than that of one of .062 dia.

 

[Will Henry]

On a Remington 700 or 40X, I harden selectively the cocking cam and polish it. Just as I would on a Mauser. Heat to bright red with a carburizing flame and quench in oil. Polish with a 600 grit wet or dry paper. WH

 

[BoydAllen]

Boyd,

Well I respectfully have to disagree regarding the Tubb dual spring.
The spring rate is less so therefore the cocked weight is less with the same travel.
Educate me on how with two 11.03 lb/in springs (which equates to half 5.52lb/in for overall installed spring rate)
Also I would like to know how it is a 24lb spring when cocked with 0.050 wire diameter.
Remington Long Action Spring
Tubb Duo Kit have the following dimensions;
Wire diameter Size = 0.050"
Spring OD = 0.394"
Free Length = 3.72"
No. of Active Coils = 20
Total Coils 22
Spring Rate: 11.03 lb/in each spring
One CW wound and one CCW wound Spring
0.095 Spacer
Overall spring assembly - 7.54”
Remington Action is roughly 3.33” cocked

I respect your knowledge and I am happy to be educated and see all the calculations to get it to 24lb cocked as my calcs I did say otherwise.

Looking forward to your reply

Cheers
Michael

Hi Michael,
Perhaps you are overlooking the role of the free length in all of this. With the same number of coils, uncompressed springs' free lengths can vary, and it seems to me that when a spring is compressed more, its cocked weight will be more even with the same wire diameter and number of coils. The advantage is that there is less "stack" during cocking.

 

[Michael Huebner]

Hi Michael,
Perhaps you are overlooking the role of the free length in all of this. With the same number of coils, uncompressed springs' free lengths can vary, and it seems to me that when a spring is compressed more, its cocked weight will be more even with the same wire diameter and number of coils. The advantage is that there is less "stack" during cocking.

Hi Michael,
Perhaps you are overlooking the role of the free length in all of this. With the same number of coils, uncompressed springs' free lengths can vary, and it seems to me that when a spring is compressed more, its cocked weight will be more even with the same wire diameter and number of coils. The advantage is that there is less "stack" during cocking.

Boyd,
You have resurrected this old thread.
I am not sure what your trying to say. I am ready to be educated!
The DUO spring is around 19-20lb that is why it feels easier - period. Bought it, installed it, tested it, did the calc’s, sent it back for a refund which I received as it is not as advertised @ 24lb no matter how it’s tested. I believe you cannot get 24lb from 0.050” wire in a firearm application for Remington 700 style.