Rifle-to-pistol chamber adaptor

I got this one at a show, and then started reading in a forum (not IAA) about such adaptors. Some people say that these do not produce a good chamber mouth seal and leak gas into chamber, thus producing fouling. Is it a significant/common problem?

Back in the 1950s (and earlier, they were fairly common and widely advertised, in several calibers. I believe some were sold by Marble, the gun sight company. Once I had one in .30-30 using I think .32 ACP and don’t remember anything unusual happening when fired. I haven’t seen one in a long time, even at gun shows.


Most of them are called Auxiliary Cartridges, although some do go by other names, such as adaptors, chambers, holders, etc, depending on their construction and use. They’ve been discussed quite a bit on the Forum. A quick search should turn up several threads.

They were popular back in the 1930s through 1950s when the average guy had but one rifle to use for all of his shooting. They never were really as functional and useful as the advertising would have you believe but, nothing ever is.

They make an interesting collecting specialty on their own. You could probably find 100+ different ones. Some command pretty good prices.

To your question - no, they do not effectively seal the chamber. Fouling needs to be cleaned out after using them but you’d clean after using conventional cartridges too. So, no big deal.

Wait till you see the next IAA journal