Recoil Spring Specs- Anyone Have Info

[Grease Gunner]

Hello All:

After having the buffer pilot failure which i fixed with a WW2 Savage, My attention Now Turns to Replacing the Bent and Kinked up spring

I plan to photo the Actuator which is knurled so members can tell me if its a WH or not. After having the Buffer pilot go out the back

another inch and stop; it has me worried about making sure the internals are GI

 

So with the Recoil Spring for the 1928 and 1928a1 spring, does anyone know the quantity of coils and the coil thickness so I can sort my springs?

 

Thanks!

[bob241]

look at the print. look on left side, pick out prints, go down to spring, recoil

 

http://www.nfatoys.com/tsmg/pdf/5153024.pdf

[Grease Gunner]

Thanks so much!

[Grease Gunner]

Has anyone clipped coils off a recoil spring to make it run slower??

[StrangeRanger]

It's counterintuitive but cutting a coil spring actually increases the spring rate

[Grease Gunner]

It's counterintuitive but cutting a coil spring actually increases the spring rate

 

I have always heard the opposite that a stiffer spring really sends the bolt home much faster on the return .

[StrangeRanger]

When you cut a coil spring 2 things happen:

First, the spring rate, i.e. lbs/inch of compression, increases

Second, for any amount of bolt travel the spring will be compressed less

 

So the spring restoring force at any given point of bolt travel may be more or less than before you cut it due to the reduction in force from the lesser initial compression but the spring will gain force at a higher rate as the bolt motion continues. It can all be calculated but it's really not worth the effort

 

FWIW just buy an Extra Force recoil Spring from Wolff and call it good

[reconbob]

It may be counter intuitive, but if you say, cut the spring in half, there would

barely be enough power in the spring to move the bolt forward. The bolt would

recoil much faster due to less spring force, and counter recoil/move forward

very slowly due to a much weaker spring. So reducing the length of the spring

will not increase the rate of fire.

I think you can use a Grease Gun as an example. Heavy bolt, light springs,

very slow (for an SMG) rate of fire..

This reminds me of years ago in Sports Illustrated they had an article where

a guy researched the science of shooting a basketball and he concluded that

the higher the ball was shot, the larger the area available for the ball to fall thru

the rim. In other words, a high lobbing shot has a better chance than a line drive.

He was set upon by many because according to his calculations (as Wiley E.

Coyote would say) the shot with the highest percentage of success would be a shot

that went straight up, which of course has a zero percent change of success.

 

Bob

[StrangeRanger]

If you cut coils off a spring the spring rate in lbs/in will always increase. However, there will also be an offsetting loss of force due to the fewer inches of initial compression so the net effect may or may not be a gain in restoring force at full stroke in any given application.