1911 recoil and main spring info.

I'm making a 1911 spring tester using a Chatillon force gauge. My friend has one so that spring can be inserted into tube, compress to line on the window for correct compressed length using a spring weight scale. I measured the dimensions for both the recoil and main spring version using my depth micrometers. I got 1.587" for recoil spring and 1.225" for main spring. However online drawing of GI 1911 has 1.81" for recoil spring and 1.062 for main spring.
 Does anyone have the compress lengths of the springs? Seems there is quite a bit of difference between what I measured on my friend gauges and the GI drawing online. Maybe I read depth micrometer wrong since reading are opposite that of a standard micrometer. Though I did check the depth mic. rod length with machinist scale.

I use 1.810 on my spring tester and new springs measure what they are marked.

Greetings,

From Drawing 5013200, Spring, Recoil...

Load at Compressed Length of 3.72" = 8.00 LB +/- 0.50 LB

Load at Compressed Length of 1.81" = 13.55 LB +/- 0.60 LB

********************************************************************

From Drawing 5013208, Spring, Helical (Main Spring)...

Load at Assembled Height of 1.312" = 22.0 LB +/- 2.0 LB

Load at Operating Height of 1.062" = 29.5 LB +/- 2.0 LB

Cheers,

Dave

Yes I know what the drawing has, I down loaded them and compared them to the dimensions I got from my friends gauge. I was surprised to see a great difference. Either I read the dept mic wrong but I know how to read it or I used the wrong line in that the gauges had a different line for the 3 different types of 1911s (Officers, Commander and Government).

So as to be listed as a new post I'll ask here rather than edit my previous post.
 Does anyone know where the compressed length of the spring is measured to determine the rated poundage of the spring force? At the point slide is returned so that lock back will occur? Max slide travel? Or some other place?
 I have a full guide rod on my recoil spring that is flush with the recoil spring plug when slide is in the closed position. I can measure the distance it protrudes out of the plug. Then measure the distance from the face of the spring guide to the edge of the plug then add the depth inside of the plug to get the first compressed length, subtract the amount the full length guide rod protrudes at the correct location and subtract is from the first compressed length to get the second compressed length.
 Using the compressed length of the two listed in the online drawing then 3.72 - 1.81 = 1.91" of slide travel for the recoil spring rated location.
 Not sure why I would need to know the first compressed length poundage but I guess it will be good to know especially for those variable rate springs.

It's not real clear what you are asking.

When the overall length of the recoil spring is compressed to 1.810" it should be at the rated force. A 12 lb spring should measure 12 lbs when compressed to an overall length of 1.810".

Don’t forget that springs have a rather large tolerance on load ratings.  +/-10% usually so even if you compress it to 1.8-odd inches the force can be somewhat different.

Yes I know but can't figure out why measurement taken from a purchased spring gauge is so different from the dimensions on the drawing. My friend remeasured the main spring gauge using a different method and we are .004" apart. Close enough but 1.225 is not the same as 1.062 listed as compressed length of the main spring! Our dimensions are taken from a purchased gauge that looks quite professionally done.
 He's going to check the recoil gauge again because my measurement 1.58 is way to short, slide will never travel that distance!

So this would be better than stabbing a screwdriver through a spring and into the base of an empty soup can on a bathroom scale?

Any thing will be better that that. I can easily make the item in the photo. The measured distance to the line is 1.225" and confirmed by my friend but online drawing of 1911 has 1.062" listed as compressed length of main spring. So as to make an accurate gauge I purchased a couple of linear slides with carriages and will use a screw to push the tube toward a Chatillon force gauge (far more accurate than a spring fish type scale). All I need is the correct compressed length! I've talked to a few well known smiths and get different compressed length for the springs! I would hate to buy a spring, test it and find it's not what it is as per the label on the package, complain to the vendor only to find I was using the wrong compressed length! Simply put if I purchase a 19lb main spring I want 19lbs or if I test a spring from a 1911 I want to know what it is!
 Foe example I have a Nelson .22 conversion, Larry recommends a 19lb main spring so I purchased 19lb main spring from EGW but gun will not fire with first drop of hammer but will on second drop. Is it the spring or another problem??? Ordered another 19lb spring, same thing! No change! If I add a heavier spring then recoil spring must be lowered. Changed hammers, same thing no change and will not fire with first drop of the hammer. Tried different ammo Eley SK and others, same thing no change. Conversion is new never used and firing pin spring is as it was installed by Nelson!
 Make it work, yes I did with a little modification but why doe it not work as it's supposed to! Currently it's functioning with 17lb main spring from EGW. That is what is on the package label!

Use a wolf 19lb spring

I called Wolff, ordered 2 main spring kits + an 18lb spring so I have them all from 15lbs to 21lbs. I also have a new in the package 22lb from EGW.
 I also asked the compression measurement for the recoil and main spring and got yet a different number! They use 1.625" as the compressed length of the recoil spring. My friend re-measured the gauge and came up with 1.629", if I use the revers of the .033 reading it would be .067" so my measurement came to 1.618" and the width of the gauge line is .025" So that confirms the gauge maker used .1625" same as Wolff. Why I don't know and wasn't going to tell Wolff they were wrong since they were the experts.
 As I said I have the conversion firing with a 17lb spring and it might work with less when the Wolf springs are tested in the gun.
 BUT I still don't have a compression length for my soon to be built spring tester! But I'm rethinking my gauge build.