我想，制造尺寸上的微小差异造成了这个问题，而且这些口袋的尺寸并非专为M4弹匣设计的。

I think that minor differences in manufacturing dimensions accounts for this, and the pockets aren't specifically sized for M4 Mags.

youdao

依据概率统计的相关理论进行机构设计，即考虑构件制造尺寸的随机误差，以保证机构运动的精度在允许的误差范围内。

According to the probability and statistics theory, the mechanism is designed, that's considering the random error of the component to make sure that the motion accuracy is in the allowed error range.

youdao

为了达到这样的效果，小组改变了光通过玻璃方式，是通过制造了个毫米尺寸的单片玻璃空间变向转换器。

To do so, the team altered the way light passes through glass by creating millimeter-sized devices called monolithic glass space-variant converters.

youdao