Benet or Bar and Anvil 56-52 Spencer?

This non-magnetic Benet-primed or bar and anvil primed cartridge looks unusual. It came to me identified as a 56-52 Spencer. Please see photos.

56-52 Spencer RF HS

The dimensions (inches) for the cartridge in the photos are:
RimD: 0.662
BaseD: 0.5665
NeckD: 0.5415
BulletD: 0.527 (at case mouth)
CaseL: 1.03
OAL: 1.39

First unusual thing is the cartridge is Benet-primed or bar and anvil primed and not a rimfire.

Second unusual thing, is the rim diameter is closer to the 50-70 (0.666") and its brothers (50 Cadet and 50 Carbine) than to the 56-52 cartridge (~0.626 to 0.639").

Third unusual thing, is the flat nose bullet. I have several Spencer cartridges and have seen numerous photos of them, but none have a flat nose bullet. Every Spencer cartridge I have seen has a conical bullet.

My questions are:

Is this really a 56-52 Spencer cartridge or is it someone’s reload or hybrid?

Was the 56-52 Spencer ever loaded as a Benet or bar and anvil primed cartridge?

Why is the rim diameter so much greater (0.023" to 0.036") than published 56-52 measurements? (Maybe the measurement difference isn’t all that great considering tolerance control back then and the need for reliable firearms using black powder?)

Was the 56-52 Spencer ever loaded with a flat nose bullet like the one in the photo?

Thank you for your thoughts.

Heavyiron

It doesn’t seem like a Spencer cartridge to me as I don’t think this would feed well with the Spencer’s tubular magazine. If it’s a fake it’s good work. Jack

Jack thank you for your response. I agree the flat nose bullet is not a great choice for the Spencer action. Yes if it is a fake it is a good fake.

I thought all Spencer’s were rimfire as well. I know the 50-70 was a Benet primed, rimfire, Farmington and centerfire cartridge at one time or another. Never saw a benet primed Spencer. Not saying they didn’t make any, just never saw one.

Best.

The Spencer was made as an inside primed centerfire but with Martin’s patented priming system.
Martin primed Spencer head Martin Primed Spencer oa

Learned something new, again.
Thanks guys.
Zac