Cartridge base alteration??

[Black River Smith]

I thank you all for the additional replies and new Rook idea.

To answer some of the additional questions about the conditions of the brass --- The extractor groove on them has not been modified.  The diameter of the bases are all around 0.435, like new Win.  The OAL is standard at 1.285"( I checked OAL on all 500 purchased pieces of mixed brands after sizing).  Did not lose that many pieces of this brand, so did not think about 'something funny being up' like a cartridge conversion alteration.

Do appreciate all the insight you all have provided into this issue that I have never experience before.  Thanks again.

[Hair Trigger Jim]

Back to the .351 idea -- if it had an extractor groove from the factory (.357 Magnum usually does but doesn't require it in a revolver), then that probably wouldn't have been modified.  And the case would still be full-length, as the .357 Magnum case is just a bit short but useable (.357 Maximum would have to be trimmed though).

HOWEVER, as the rim doesn't seem to have been trimmed, that's probably not the answer.  While I suppose the breech face and extractor could be modified (to reduce time spent modifying the brass?), that hardly seems practical.  And I have no idea whether the cartridges would still feed through the magazine.  I've handled quite a few Winchester self-loading cartridges but never had a chance to use one of the rifles (yet).

And I have no experience with Rook rifles.

[Professor Marvel]

Ok.

I had to go look.

Rook rifles are for shooting .... Rooks.
And rabbits.

Rabbits is self explanatory, but Rooks?

I followed the links and found that rooks are birds that live in colonies. Well. Thanks.
And the brits liked to shoot them with rook rifles. Well. Thanks again.

Unfortunate facts: rooks were considered pests, adult rooks were considered inedible, so a "rook shoot" often consisted
Of shooting imature rooks who could not yet fly, sitting in the trees.

Talk about shooting a sitting bird.....

I discover that rooks are

" The rook (Corvus frugilegus) is a member of the family Corvidae in the passerine order of birds. It is found in the Palearctic, its range extending from Scandinavia and western Europe to eastern Siberia. It is a large, gregarious, black-feathered bird, "

Still not helping any....

Finally I find out that they are basically Ravens.
Finally.
Omg.

And the rook rifles and their calibres were outmoded by the .22 rimfires.

Well hmph.

Yhs
Prof aaaaaaaargh

[Reverend P. Babcock Chase]

Thank you Perfesser,

Your exhaustive research has demystified the issue. I still have no idea what a rook tastes like as I have never eaten crow. I almost found out what seagull tasted like as i was shooting them at a nearby beach. A game warden came running up to me and told me to stop. He asked my why I was doing it and I pointed to a sign that said: "Fine for Shooting Seagulls".

Rev. Chase
ps: game wardens have no sense of humor.

[Coffinmaker]

Aha 

Not Chicken.  Taste like Snake.

You don't wanna no what Sea Gull taste like.  I ain't gonna tell ya how I found out neither.  Nanny Nanny Poo Poo

[Lucky R. K.]

Rooks were basically British crows, and the Rook rifle was the method used to control them at that time. Most of the major British gun builders of the time offered a Rook rifle, usually around .300 caliber. A friend used to have a Rook Rifle match on his farm in Indiana where there would usually be 15-20 men and women shooting the match.

Lucky