Regardless of the reason, SRPs are a practical substitute for SPPs. I am approaching 50 years of their use. For some calibers I don't load often, such as .32 ACP and .380 ACP, I do use SPPs. But for .32-20, .38 Special, .357, 9mm, .38 Super, and 9x23mm Win, it's always SRPs. The same SRPs I use for .223/5.56mm and .30 Carbine. I don't worry much about who makes them. In my case, usually Winchester or CCI.