Feeding Question and Spring Fatigue Question in 300 BLK magazines an issue?

[mannythegreek]

Hello,

I was wondering if anyone had any knowledge of spring fatigue in magazines that are fully loaded with 300 blk (or even partially loaded).

From wikipedia, an average 62 grain projectile in 5.56 weighs 11.8 grams or about 183 grains in total. 30 rounds of 5.56 should weigh 354 grams or 5490 grains in total .

30 rounds of 300 blk should weigh around 7300 grains or 470 grams. Do you think this would cause an issue with spring fatigue?

Although the pressures of both rounds are equal (as explained in an earlier post) What about feeding the larger (and heavier!) cartridge from the magazine? I realize that changing buffer weights is a no-no (as described by other users who have done this), but it would seem that the heavier cartridge would ideally require a heavier spring. Would appreciate your responses!

-MannytheGreek



https://en.wikipedia.org/wiki/5.56%C3%9745mm_NATO

[Marty916]

Not having any empirical data, this is only conjecture but I would think that the added static bullet weight would have much less impact on spring fatique in a static state than dynamic cycling of the spring during use.

[skyugo]

i'd agree that ideally the heavier cartridge would get a heavier spring. It's probably still inside the "safe zone" with normal 5.56 springs. I'd say making sure your bolt speed is lowered a little would be more than enough to ensure cycling.
as far as fatigue on the spring goes, probably not an issue, it only matters how many times it is deflected, not about how much force deflects it .

[GunnutAF]

I have had my 300 Blk for about 5 months now other then getting the COAL right to ensure proper feeding I haven't had any issues with mag/feeding. Could it become a problem -sure it could but until it does not going to worry about it!

[wahoo95]

Never an issue in mine

Sent from my DROIDX using Tapatalk 2

[rsilvers]

Spring stress is a function of how compressed the spring is. Spring compression is a function of how many rounds are loaded in the magazine. Heavier rounds do not compress the spring more.