What's with small primer 45"s?

[gunbugs]

Originally Posted by Schutzenbob

Generally, with rifle calibers small primers were used in magazine rifles to decrease the possibility of detonation in a magazine tube. It could be that some folks feel that there's a risk with the large pistol primers in a 45 magazine. However, with the scarcity of primers it's probably a good idea to have some small primer cases on hand just in case.

The only reason SP 45acp exists is that over the course of millions of rounds, small primers are cheaper than large primers. They first started being used in 45 with CCI Blazer aluminum case ammo.
Most tube fed firearms, except for 22lr, are large primer calibers. (The exceptions being 357/38, 25-20, and 32-20), most others are bigger calibers, 45-70, 35Rem, 30-30, 32WS. 40-65, and a myriad of other obsolete big bore calibers. The detonation of primers in a tube fed firearm is mostly a non-issue, even with round nose bullets. Size of the primer will not make a difference.