Reisings are fun SMGs. They were designed in the '30s and thus originally ran lower-powered .45 ammo. If you run them with today's ammo they do run faster than original spec ... but a half-century of use and wear often makes them only reliable with hotter ammo.

Mine ran fine with downloaded .45 ACP. It was a technical pre-war and I bought it with the original FedLabs fitted hard case, and paid a premium. The deep bluing and walnut stock are gorgeous. I did an FOIA request and the Form 5 to the Pittsburgh PD was approved on Dec. 8, 1941, the day after the attack on Pearl Harbor; the Pittsburgh PD was arming up to defend the steel mills, and it was part of a bulk purchase by them, though only a few came with fitted hard cases.

I bought mine without any knowledge of its history for $3.7k; after I researched its history, I sold it for $8.5k to a WWII-fanatic friend who just had to have it. Wish I still owned it ... it ran 100%, but the bluing and wood were so beautiful and perfect, I couldn't shoot it anymore and it became a safe queen. Sigh.

Here she is with the original prewar factory manual, hard case, NIB unfired mags, FOIA report, Pittsburgh LE patches, box of original ammo, etc.:

If ya like that pic ... here's a couple more, never-uploaded, pix that really show the prewar quality (and the hand-fitting). BTW, this is the original 1941 bluing -- check out the muzzle. I'm not sure it was ever fired, though it does have some armory-rack dings and dents. But I'm guessing this one was assigned to a ranking officer.

IMHO, the condition is incredible for a 75-year-old duty weapon (though IIRC from the FOIA, it took its PPD pension and retired in the late '80s; it only had one non-SOT owner prior to me; it came from his estate).

It's now in a private collection in Maryland, last I heard. I do miss it.