Hi Brock and welcome. This rifle has been completely re-engineered by upgrading the quality of the steel for critical components. The new S7 Steel Bolt Carrier and feed ramps including a tool steel plate front trunnion. S7 is often referred to as a "Shock-Resisting Tool Steel" is commonly used for chisels, jackhammer tips and other tools which need to remain tough even under maximum shock and compression. In short, the VSKA adds a new heavy-duty spin on a old trusty favorite. Cheers and Happy New Year!