What's with small primer 45"s?

gunbugs · 08-14-2022, 03:26 PM

Quote:

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.

Patrick Sweeney · 08-15-2022, 04:45 PM

the story is long and ugly. Police departments insisted in lead-free primers because of heavy use on indoor ranges, and the apparent inability to make the officers involved actually run a clean range.

The new compositions had a higher force, and primers backing out became a problem. The ammo companies tried to solve it by making the flash hole bigger, so there would be less back thrust.

the long-term solution, for some, was to use small pistol primers, and they also found it helped make loading more efficient and less costly. (when you load by the million-round production lot, even a small cost change matters.)

So, save them up, they work just fine, and you can always trade them, or hold them in reserve for when you have small but not large pistol primers.

08-15-2022, 04:45 PM	#2
Patrick Sweeney User Join Date: Jun 2005 Posts: 77 Thanks: 0 Thanked 58 Times in 29 Posts	the story is long and ugly. Police departments insisted in lead-free primers because of heavy use on indoor ranges, and the apparent inability to make the officers involved actually run a clean range. The new compositions had a higher force, and primers backing out became a problem. The ammo companies tried to solve it by making the flash hole bigger, so there would be less back thrust. the long-term solution, for some, was to use small pistol primers, and they also found it helped make loading more efficient and less costly. (when you load by the million-round production lot, even a small cost change matters.) So, save them up, they work just fine, and you can always trade them, or hold them in reserve for when you have small but not large pistol primers.