Testing a recoil spring the low-tech way?

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mfree

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Is there a simple way to check the weight on a recoil spring, like maybe pressing down on the spring (over a guide rod, of course) with the end on a bathroom scale? Precision isn't terribly important.... I think the spring in my CZ75 has gone kaput (extremely heavy recoil, bad muzzle flip, slide stop pin warping) and I'd like to know before I throw money in Wolff's direction.

Any hints? The gun was walking all over me saturday, engendered a god-awful flinch since I thought I was going to leave front sight marks in my forehead more than once. I'm not a little guy, I don't *think* I was limp-wristing... the big clue was that I was shooting my CZ52 immediately before that and the recoil was *much* lighter and more manageable. I was under the impression that hot 7.62x25 was supposed to be a harsh round :) My 75 was making me *hurt* with winchester white box...
 
Testing suspect recoil springs:

1. Buy a handful of recoil springs.
2. Throw away the recoil spring that you think might be worn out.
3. Install one of the new recoil springs.
 
Recoil springs are dirt cheap. Just buy a new one. Why wonder ? Don't just buy one, buy several, that way you will be more likely to keep up with the maintainance of your pistol.
Once you get the new springs you can hold your new spring up against the old spring and look to see if the old spring is compressed.
 
Mikey is po'. I waited nearly two weeks before I could afford to go get ammo for my CZ52 and try it out at the range.

EDIT: That's not an excuse, btw... but it is a legitimate limitation. It'll be a while before I can afford Wolff's equivalent of an armorer's kit.

It appears that the spring stopped pushing the bathroom scale down at around the 11 pound mark. That's not a happy number, from what I see in other places...
 
One recoil spring is $7.89.
Sorry to hear about your financial condition, I have been there.
 
I have a Wolff gunsmithing pak and make double and triple recoil spring assemblies sometimes.

Joe at realguns made a spring tester
http://www.realguns.com/Commentary/comar16.htm



What I do is put a string on the trigger guard of the pistol, hang a bucket or ammo can on the string, and hold the gun by the slide with the muzzle pointed toward the floor. Now I add ammo to the can until the slide just opens all the way while shaking the pistol up and down to overcome static friction. Then I put the bucket on the scales, and voila, the weight scale reads the spring force.
 
Hmmmm.... very similar to my method of checking trigger pulls. Coffee can, coat hanger, cooking scale and a box of 200 grain bullets.
 
I did the ammo can, ammo, string, and weight scale method on the slide pull of a Kel-Tec P-3AT .380 this morning:
1) initial opening: 4 pounds
2) cocking hammer: 12 pounds
3) slide all the way back: 9 pounds +/- a couple pounds of friction

Then I got out the FDK10 that I got off Ebay for cheap [I sure didn't pay the $145]:
http://www.wagnerinstruments.com/fdk_dial_force_gauge.php

1) initial opening 4.5 pounds going back, 3.5 pounds going forward
2) cocking the hammer: 11.5 pounds
3) slide all the way back and moving back: 12 pounds, moving forward: 6.5 pounds


I am very pleased with the tight co-relation between force and gravity where I am on earth:)
 
I've got a 20 pounder in the gun now, waiting for time/money to hit the range...

I just remembered that when i was firing the CZ75, I could hear tinging behind me. The only thing that could have been was the shells getting launched into the metal chairs behind me with some force remaining. I'd have hated to be standing right behind me, because those chairs were a good 12 feet away :D
 
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