Re: How many magazines per rifle ?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ORD</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tylerw02</div><div class="ubbcode-body">Repeated compression/decompression wears mags. Not constant compression. </div></div>
While generally correct with respect to mag springs wearing out/weakening, that statement as a whole is not correct. If you load mags to their full capacity and leave them that way, you create pressure on the feed lips which over time will cause them to deform and to malfunction, and it can also take a toll on the mag bodies themselves with some mags, causing them to bow. This is one of the prime reasons that Magpul offers their snap on "dust covers" as it both protects one of the crucial areas of the mag and keeps debris from entering the mags, as well as taking that pressure off the feed lips by pushing the rounds down and off the lips slightly. </div></div>
This was the original intent of Magpul when they designed the dust covers. However, continued testing by Magpul of their mags has revealed that it is not necessary. Magpul claimes that it is fine to leave their mags fully loaded with 30 rounds for extended periods of time. If you don't believe me, send them an email and ask them yourself. They have found no evidence of feed lip creep or spring set. One of the reasons for this is that a P-Mag 30 is actually capable of holding 31 rounds, but won't seat on a closed bolt this way. With 30 rounds it will still seat on a closed bolt, and not set the spring, but if you cram 31 rounds in one, you do run the risk of setting the spring. So, 30 rounds in a 30-round PMag for "extended peroid of time (at least 6 years) is apparently fine, even if you don't use the dust cover.