Download -1 in a magazine?

[hoot]

Recently took a LE training and the LEO Instructor mentioned that some departments are downloading mags by one less round to lessen the over compression on the mag spring (this was referencing GLOCKS).
Any data on this to keep the springs from weakening?

[Dietrich]

I may be wrong but I don`t think that a magazine is over compressed if it`s filled to capacity.If you tried to go +1 above capacity you could damage the spring but not at its` normal capacity. There are more knoledgeable people in this forum than I am and I`m sure they will weigh in with factual information but I`m almost 100% certain that I`m correct.

[arizona98tj]

That would be correct assuming the mag design was correct and that they didn't end up designing in an over compressed spring.

Not saying any company did.....but that would be a good reason to download a mag, assuming the original cartridge count was too much. Got any friends that are mechanical engineers?

[mr surveyor]

I'm waiting for mr. 72's response. I think he knows a "little" about springs.

[oldtex]

Recently took a LE training and the LEO Instructor mentioned that some departments are downloading mags by one less round to lessen the over compression on the mag spring (this was referencing GLOCKS).
Any data on this to keep the springs from weakening?

I don't know about the mechanics of spring compression, but I've run into folks who load their mags down one round with some weapons. If they're changing mags with the slide forward, they find it easier to fully seat a mag downloaded one round than a fully loaded mag.

Is this what the instructor was addressing?

[Spank the Monkey]

I always thought that working a spring was good for it...in fact made it stronger as long as it wasn't overstreched. I just knew I should have paid more attention in Physics calss :o.

[zena]

I'm with you OldTex. I download 1 with certain guns for faster/smoother reloads on the move. Otherwise, top 'em off! :86:

[ltxi]

I've always loaded my Glocks -1

[.45mac.40]

Question >>>
6 rd. mag. charge only 3 rds.
7 rd. mag. charge only 4 rds.
10 .... charge 5 ....and tha' 13 rd. mag. only load 6 .....
why would ya' want less rds. than what the magazine was designed for ???
Fill em' up ..... take care of them.
Mac

[Grabbrass]

I've read more than once on the internets that Glock overdoes it on mag capacity for the sake of the spec sheet. Haven't you ever wondered how/why Glock gets 17ds. of 9mm into a magazine the same size that Sig and H&K pack 15rds into? But just because it might be prudent for a Glock owner to download -1 doesn't mean it's something you need to do with other brands.

[500KV]

Know nothing at all about spring fatigue, if it really exists, but I do change out mags periodically in home defense/CC handguns just to give them a "rest".
Also to rotate ammo. Maybe once a month.
Anyone else do this?

[pistol pete]

I have not heard of this either, but I do like to change the mag I carry in the pistol every once and a while. I would think that Kahr would have posted something on thier Q&A section if that were the case.

[mr surveyor]

it is my understanding that springs ARE at rest if left uncompressed or compressed, either way. The kinetic process of compression-uncompression is what actually causes fatigue in modern spring materials. So, if you are tryinig to avoid unnecessary spring wear and tear, leave 'em loaded.


surv

[ltxi]

Springs left, especially severely, compressed for long periods of time will eventually take a set and lose their elasticity and ability to function properly. That can be different from fatigue in the more proper sense. I also agree with the thought that Glock "overstates" their practical magazine capacity and down load both my G23 and G27 (which use the same spring, go figure) by one. Even so, the only "normal" feed failures I've ever experienced in a Glock came with two magazines that had been inadvertantly left minus one loaded for somewhere close to ten years. New Wolff springs fixed that issue.

[Pistol Pedro]

I download by one the magazine of any pistol I carry. I do this so I have someplace to put the round that is in the chamber should I need to unload for any reason. I do this on my Glocks and my Kahr.

[Longitude Zero]

I have read and heard of downloading and the supposed benefits but I have never seen any data to prove the case one way or another. I load to mazimum capacity.