From: [b--gl--y] at [hc.ti.com] (Ross Bagley)
Newsgroups: rec.guns
Subject: Re: Storage of ammo in clips?
Date: 22 Apr 1994 17:17:17 -0400

[l--o--e] at [xenon.arc.nasa.gov] (Soren LaForce) writes:
#[d--tz--u] at [uxa.cso.uiuc.edu] (putzolu david) writes...
[...snip...]
## 
##The engineers (ok, engineering students :) told me that if a spring
##is kept under constant tension and is within its deformation
##limits, it should not get worse over time.
#
#This generally means that the student has a book that supports what he 
#said.  It doesn't mean either is correct.

Actually, no.  That statement is correct.  It takes certain elements in
reality and dismisses them as unimportant, but for "reasonable" periods
of time, the spring won't change.  Leaving bullets in a magazine places
less stress on the magazine spring than moving the bullets around from 
magazine to magazine so one spring doesn't stay compressed for too long.
The repeated action fatigue creates many more microfractures in spring
steel than a constant load within the limits of the spring.
 
#Or even if correct, where are the deformation limits?  One round?
#Five rounds?  Full?

Spring steel has an extraordinarily high modulus.  A correctly built magazine
should be able to have the follower compressed all the way to the base-plate
of the magazine for months without spring deterioration.  By leaving one
or two bullets from the magazine, the spring compression is a fraction of
the fully loaded magazine, and barring rust or abrasion, the spring should
last indefinitely.

#I have a book that says stuff from which you can infer that the width
#of a tire has no effect on it's ability to provide traction.

Guess what.  Omitting certain variables, like surface deformations in the
rubber and rubber cohesiveness, the width of a tire has absolutely no
effect on it's ability to provide traction.  It's a fact, Jack.

#I guess no one has bothered to mention this to the Indy car folks!

They absolutely have to deal with those variables and many others in 
order to push the rubber as far as they do.  Wanna see a thin tire, with
less weight above it out accelerate an Indy car?  Watch unlimited
motorcycles.  They can't turn as fast, but boy can they accelerate...

#Engineering students (and some engineers too) often haven't figured 
#out that what they are learning are *approximations*.

What they are actually learning are ideals.  Certain variables are held
fixed or considered to have negligent effect within the parameters of the
equations.  Within those restrictions, the equations that all those little
second year engineers are learning in Mechanics I and Physics III are
completely and exactly correct.  Accounting for nonideal situations is
what happens a little further on in life.  

You have to simplify things in order to characterize them.  The complete
description of exactly what happens when every bullet fires is far too
complex to actually deal with.  So we idealize things.  We say that the
"wave front" of the powder burning is a plane in smooth motion.  We say
that bullets are identical if they come from the same lot.  We say that 
the primer explosion is a uniform shape, that the crimp is uniform, that
the case wall is uniform, that the the bullet jump distance doesn't 
affect accuracy if it's small enough...  We make approximations to make
things understandable.  

Don't cycle your bullets through your magazines.  Load up a magazine and
leave it a few rounds short of full.  Then leave it until you use it.

You will save your springs.

Ross Bagley	[b--gl--y] at [eli.hc.ti.com]

If I spoke for TI... ah, forget it, you know what I mean.