Umm, How Does One Measure Spring Weights?

Just realized that after borrowing my Mom's old wadgun for a few months, I had swapped out the recoil spring with a longer one from Dad's box 'o parts.

Not even sure that the longer ones are truly hardball springs. Since I'm refurbishing two GI builds and a first-generation Gold Cup, how do we determine what the springs are?

From the old Service Rifle days, I remember a Garand Op Rod Spring had to be so-and-so long with a tolerance of minus-so-much, and should compress to not shorter than another length under a vertical load of so many pounds.

I'm pretty sure that 1911 recoil springs are measured the same way.

I trust you guys more than the USPSA guys--sounds like they are under-springing and either battering or needing a Shok-Buff in their search for "flat"-recoiling raceguns.

Oh, once we know what the springs are, what's right for hardball and what's generally right for 200-gr SWCs at 750-825-ish fps? No slide-mounted optics, but one of them will always be using a grip mounted dot if that even makes a difference.

Generally curious about the M9s too. Or do you even need to fiddle with springs with the 9mm popgun?

Universal spring tension tool - I bought one because I had too many springs sitting around unlabeled.

http://www.brownells.com/gunsmith-tools-supplies/handgun-tools/magazine-tools/universal-spring-tension-tool-prod56227.aspx?psize=96

I run a 18 1/2 Wolf in my hardball gun and a 13 in my wad gun (frame mounted optics).

Nice Universal System!

You might also check out this other thread:

Earlier Spring Weight Thread

I seem to remember from high school physics class that the spring force ("pounds") is the force needed to compress a spring one inch, from the resting state.  So, if my memory is still good (and it's like a steel trap-old and rusty), you coul make your own spring force measuring device pretty simply.  Some sort of scale (digital fish scale), a long light bolt with a washer, and a ruler.  Hook them up, compress one inch, and record what the fishing scale reading is at one inch compression level.

buttstock wrote:I seem to remember from high school physics class that the spring force ("pounds") is the force needed to compress a spring one inch, from the resting state.  So, if my memory is still good (and it's like a steel trap-old and rusty), you coul make your own spring force measuring device pretty simply.  Some sort of scale (digital fish scale), a long light bolt with a washer, and a ruler.  Hook them up, compress one inch, and record what the fishing scale reading is at one inch compression level.

I think in the case of the 1911, the spring weight is measured with the spring compressed to its length in the gun, when the slide is in battery.  There are some suggested lengths and alternate solutions in the other thread.