Prometheus
Master
Short answer? No.
Long answer, brass is better for an AR (which is what your initial question is) but the cost savings far outweigh and negate any *possible* side effects of prolonged use of steel cased.
For most shooters steel cases will never be an issue. For shooters who fire tens of thousands of rounds, the cost savings will more than make up for any issues that may be speed up by use of the steel casings.
Long answer, brass is better for an AR (which is what your initial question is) but the cost savings far outweigh and negate any *possible* side effects of prolonged use of steel cased.
For most shooters steel cases will never be an issue. For shooters who fire tens of thousands of rounds, the cost savings will more than make up for any issues that may be speed up by use of the steel casings.